Caloric Restriction vs. Animal-Protein Restriction

Caloric Restriction vs. Animal-Protein Restriction
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The lifespan extension associated with dietary restriction may be due less to a reduction in calories, and more to a reduction in animal protein (particularly the amino acid leucine, which may accelerate aging via the enzyme TOR).


Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

?Although the beneficial effects of caloric restriction on lifespan and health have been clearly demonstrated, it is difficult to implement such restrictions in our lives.” In the classic Minnesota Starvation Study, many of the volunteers suffered a “preoccupation with food, constant hunger, binge eating,” and lots of emotional and psychological issues. “Even researchers who study caloric restriction rarely practise it.” There’s got to be a better way to suppress the engine-of-aging enzyme, TOR.

That’s why researchers were so excited about rapamycin, a drug that inhibits TOR, thinking it could be caloric restriction in a pill. But, like any drug, it’s got side effects, too. There’s got to be a better way.

The breakthrough came when scientists discovered that the benefits of dietary restriction may be coming not from the restriction of calories, but from the restriction of protein intake. If we look at “the first comprehensive comparative meta-analysis of [dietary restriction],…the proportion of protein intake was more important for life extension via [dietary restriction] than the degree of caloric restriction.” In fact, just reducing protein, “without any changes in calorie level, have been shown to have similar effects as caloric restriction.”

That’s good news, because “[p]rotein restriction is much less difficult to maintain than dietary restriction, and may be more powerful than dietary restriction,” because it suppresses both TOR and IGF-1—the two pathways thought responsible for the “drastic longevity and health benefits” of caloric restriction.

And, some proteins are worse than others. One amino acid in particular, leucine, appears to exert “the greatest effect” on TOR. In fact, just cutting down on leucine may be “nearly as effective” as cutting down on all protein. So, where is leucine found? Predominantly animal foods: eggs, dairy, and meat, including chicken and fish, whereas plant foods have much less: fruits, vegetables, grains, and beans.

“In general, lower leucine levels are only reached by restriction of animal proteins.” To reach the leucine intake provided by dairy or meat, we’d have to eat like nine pounds of cabbage—that’s like four big heads of cabbage—or 100 apples. “These calculations exemplify the extreme differences in leucine amounts provided by [a more standard diet] in comparison to a [plant-based] diet.” “The functional role of leucine in regulating [TOR] activity” may help explain the extraordinary results reported in the Cornell-Oxford-China Study, since “[q]uasi-vegan diets of modest protein content tend to be relatively low in leucine.”

This may also help explain the longevity of long-lived populations like the Okinawa Japanese, who have about half our mortality rate. The traditional Okinawan diet was only about 10% protein, and practically no cholesterol, because they ate almost all plants. Only one percent of their diet was fish; meat, eggs, and dairy, less than one percent—the equivalent of one serving of meat a month; one egg every two months. Their longevity surpassed only by vegetarian Adventists in California, “giving them perhaps the highest life expectancy of any formally described population in history.” And now, we may be a little closer to answering the mystery as to why populations eating plant-based diets live the longest.

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Images thanks to Great Beyond via flickr

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

?Although the beneficial effects of caloric restriction on lifespan and health have been clearly demonstrated, it is difficult to implement such restrictions in our lives.” In the classic Minnesota Starvation Study, many of the volunteers suffered a “preoccupation with food, constant hunger, binge eating,” and lots of emotional and psychological issues. “Even researchers who study caloric restriction rarely practise it.” There’s got to be a better way to suppress the engine-of-aging enzyme, TOR.

That’s why researchers were so excited about rapamycin, a drug that inhibits TOR, thinking it could be caloric restriction in a pill. But, like any drug, it’s got side effects, too. There’s got to be a better way.

The breakthrough came when scientists discovered that the benefits of dietary restriction may be coming not from the restriction of calories, but from the restriction of protein intake. If we look at “the first comprehensive comparative meta-analysis of [dietary restriction],…the proportion of protein intake was more important for life extension via [dietary restriction] than the degree of caloric restriction.” In fact, just reducing protein, “without any changes in calorie level, have been shown to have similar effects as caloric restriction.”

That’s good news, because “[p]rotein restriction is much less difficult to maintain than dietary restriction, and may be more powerful than dietary restriction,” because it suppresses both TOR and IGF-1—the two pathways thought responsible for the “drastic longevity and health benefits” of caloric restriction.

And, some proteins are worse than others. One amino acid in particular, leucine, appears to exert “the greatest effect” on TOR. In fact, just cutting down on leucine may be “nearly as effective” as cutting down on all protein. So, where is leucine found? Predominantly animal foods: eggs, dairy, and meat, including chicken and fish, whereas plant foods have much less: fruits, vegetables, grains, and beans.

“In general, lower leucine levels are only reached by restriction of animal proteins.” To reach the leucine intake provided by dairy or meat, we’d have to eat like nine pounds of cabbage—that’s like four big heads of cabbage—or 100 apples. “These calculations exemplify the extreme differences in leucine amounts provided by [a more standard diet] in comparison to a [plant-based] diet.” “The functional role of leucine in regulating [TOR] activity” may help explain the extraordinary results reported in the Cornell-Oxford-China Study, since “[q]uasi-vegan diets of modest protein content tend to be relatively low in leucine.”

This may also help explain the longevity of long-lived populations like the Okinawa Japanese, who have about half our mortality rate. The traditional Okinawan diet was only about 10% protein, and practically no cholesterol, because they ate almost all plants. Only one percent of their diet was fish; meat, eggs, and dairy, less than one percent—the equivalent of one serving of meat a month; one egg every two months. Their longevity surpassed only by vegetarian Adventists in California, “giving them perhaps the highest life expectancy of any formally described population in history.” And now, we may be a little closer to answering the mystery as to why populations eating plant-based diets live the longest.

Please consider volunteering to help out on the site.

Images thanks to Great Beyond via flickr

Doctor's Note

What’s TOR? Be sure to watch my “prequel” video, Why Do We Age?

This reminds of the study I profiled in The Benefits of Caloric Restriction without the Actual Restricting.

Methionine is another amino acid that may be associated with aging; see Methionine Restriction as a Life-Extension Strategy to find out which foods to avoid. Both leucine and methionine content may be additional reasons why plant protein is preferable (see Plant Protein Preferable).

Other reasons why those eating plant-based diets may live longer:

 This all may help explain the results of Harvard’s Meat & Mortality Studies.

2019 Update: I have a couple of new videos on caloric restriction. See The Benefits of Calorie Restriction for Longevity and Potential Pitfalls of Calorie Restriction

If you haven’t yet, you can subscribe to my videos for free by clicking here.

200 responses to “Caloric Restriction vs. Animal-Protein Restriction

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    1. What about Leucine in protein powder? How much should be taken to suppress an increase in tor but still be beneficial for muscle growth? I use the powders and the Leucine amount is usually over 2000 grams per scoop. I want to gain size but I also drink a shake after I exercise; two scoops. Help

      1. Thanks for your question.

        Leucine is a the key amino acid that appears to exert the greatest effect on muscle protein synthesis, and to optimise this process 2-3g per meal is suggested. However, from a health perspective it may not be great as Dr Greger mentions here and here.

        Hope this answer helps.

  1. Heavy side of relief!
    I thought I was going to have to do the crazy calorie restriction diet and turn into Ichabod Crane just get a few more years on this planet!
    Look out plants, I’m hungry!

      1. When you say ” plant based diet” does that mean that it must be eaten raw, or can you use conventional cooking methods to prepare the plant to eat.

        1. I eat mostly uncooked since I am drinking veggie or fruit juices, and eating fruits, salad, nuts throughout the day. (I blend my veggie and fruit juices, I don’t juice) For my last meal of the day I may have some quinoa, split pea soup, boiled plantains, black rice, or some kamut spirals. 115 dregrees is considered raw so those might be considered raw. I don’t believe you have to be completely uncooked or raw to be healthy, but most of your food should be to get the most nutrients out of your food. Stay away from frying.

        2. Plant based is not connected to cooked or raw. It just means you eat foods mostly from plants, not from animals. Mushrooms are not plants or animals.

            1. Mushrooms are not plants, but they’re not animals either so they don’t contain cholesterol, excess protein, or much fat, so they’re ok to eat.

        3. The simple answers are: variety and enjoyment. The details are: in some cases, cooking enhances the availability of nutrients in food. In other cases, cooking damages the nutrients. My recommendation is: Don’t try to micromanage it. Eat some cooked, some fresh. And enjoy.

        4. A plant-based diet refers to a diet that is based predominantly on plant foods – legumes, nuts, seeds, vegetables, fruit, and whole grains – and includes both cooked and raw plant foods. Ideally, you should aim for variety, and this means not just variety in types of foods you eat, but also variety in preparation methods. This is because different preparation methods will affect how your body absorbs the hundreds to thousands of phyto-nutrients found in these foods. In general, most “gentle” cooking methods – stir frying, sauteing, or microwaving, for example – are excellent choices for most vegetables.

          If you want fine detail, be sure to check out Best Cooking Method. But keep in mind, the study mentioned in the video considered how cooking methods affect antioxidant levels. There are dozens of nutrients that have activities far beyond being mere antioxidants

          If you like REALLY fine detail, you may enjoy Polyphenols: food sources and bioavailability. As noted in this article, polyphenols may have important effects on human health because they are metabolized by the same pathways as xenobiotics and endogenous hormones. This may, in turn, decrease the risk of neurodegenerative diseases, cardiovascular diseases, and hormone-dependent cancers. In this regard, polyphenols may be affecting health through pathways unrelated to antioxidant activity, and considering only the effects of cooking methods on antioxidant levels would miss these considerations.

          In the end, I believe it’s important not to get too bogged down in what I refer to as “minutia,” or the extremely fine details, which, in the context of balanced, varied, healthy plant-based diets, are inconsequential. Some of the mysteries of how and why plants improve human health may never be solved, but we do know that eating these foods is one of the best things you can do to decrease chronic disease risk!

    1. Good question. So I checked Nutrition Data…

      …and aside from soy protein isolate, soy protein concentrate, and spirulina, none of which Dr. Greger recommends, I had a hard time finding any other plants with a high leucine content. I had to go through pages just to find tofu and seaweed, both of which were at almost #300 on the list.

      Search for soy and spirulina for Dr. Greger’s reports on those foods.

      If I recall properly, I believe Dr. Greger recommended limiting traditionally processed soy (not veggie burgers) to one serving a day.

      1. The numbers I’ve seen suggest that peanuts and almonds have comparatively high leucine levels, which presents a bit of a contradiction with the previous research suggesting the nut consumption is associated with greater longevity.

        1. Interesting. I’d love to see your data source.

          I’m also wondering if traditional food combining for “complete” proteins, like rice and beans, peanut butter on whole wheat bread, etc. negate the lowered leucine effect.

          1. Well, if you look at the USDA database without vegan glasses ;-) there are actually plenty of plant foods high in leucine, isoleucine or methionine.

            Dried peas are among the top sources of leucin, they provide just as much as meat. Nuts are but a little bit lower, proving similar amounts as eggs or cheese.

            The two top-sources of methionin are plant-based too: brazil nuts and sesame seeds. You don’t usually eat very much of those, though.

            1. Grams leucine / 100 g (as in this video) is not a particularly practical measure, compared to g leucine / kcal. That said, consider the diet of two hypothetical 60 kg adults consuming 2400 calories. One with a diet comprised entirely of potatoes would ingest 3.4 g leucine, while the another with a diet entirely of skim milk would 22.9 g. As their leucine requirement is 2.34 g according to the WHO, the extreme McDougaller is getting 144% of the requirement, while the dairy fanatic is getting 978% of the requirement.

              With regard to the video, mTOR may be the main cellular regulatory hub downstream of IGF-1: they’re two links in a branching chain, rather than separate strands. The full pathway is in an earlier comment here, while this is an abbreviated diagram of where leucine interacts wiith insulin/IGF-1/mTOR signalling (mTORC1 is the mTOR complex associated with growth signalling):


              1. Wow, thanks once again for this information darryl! I sometimes can get a grasp on how the chemistry works by reading various papers, but the graph you have here makes it much easier to see the whole picture. I’m waiting for the days of genetic manipulation to modify directly these pathways.

              2. LoL 2 60 kg adults. Is that the norm now?

                I mean a 60 kg male is a skeleton m8.
                Women can still have babies weighing that but come on!

                In your world women would have great difficulties surpressing the urge to shop for seed outside of the relationship. Their uncontious brain would have them throw themselves at the first meat eating male doing some repair work around the house.

                1. As you’re perhaps aware, food combining for a complete amino acid profile each meal is unneccessary, as the body stores of each essential amino acid are generally enough to get through 24 hours. Vegans mosty just need to eat some higher lysine (not leucine) foods like legumes sometime each day to ensure adequate lysine, and the rest takes care of itself.

                  So, practically looking a real life diets, vegans likely consume 150-250% of the leucine requirement, while most omnivores and ovo-lacto-vegetarians are likely around 400-600% of the requirement.

                  1. Yup. On paper, I know that. But food sensitivities cut down on the amount and variety of plants I can eat. That forced decrease in intake caused me some protein challenges, so any little but of help I could give my body I tried, not to mention issues of flavor and convenience. It makes sense for me to mix my black-eyed peas and lentils with a starch, mainly wild rice or yellow corn.

                    Eventually I had to give in and add a little animal protein to my diet à la Fuhrman. First time in 20 years. I was not a happy camper.

                    1. If you have food allergies, check out a treatment called NAET. It helped me relieve/eliminate most of mine.

                    2. Thanks for the sales pitch. But NAET has a disclaimer on their website:

                      NAET does NOT claim to cure allergies or food, chemical and environmental sensitivities.”

                      Acupuncture, kinesiology, and chiropractic. No thanks.

                    3. Sorry for the cynicism, Sebastian. I apologize for my curt response. Most alternative treatments, when scrutinized in quality peer reviewed studies demonstrate little benefit beyond placebo. Chiropractic has been proven to have benefits for lower back pain but not for any other maladies.

                    4. No worries. I’m a fellow skeptic. When I speak of NAET, I speak from personal experience. I, my girlfriend and all our acquaintances who were treated by our acupuncturist/osteopath benefited from it. When I say benefited, I mean my allergies were 90% gone (for at least a year) from the first treatment. Yet, the skeptic that I am, I still didn’t believe in it. It took me 5-7 sessions to feel more at ease with it. As for acupuncture, still speaking from personal experience, it has helped me tremendously with joint issues due to exercising and typing (I work in an office).

                    5. If you have ever heard of Airrosti, they are soft tissue specialists that are chiropractors but with advanced training. They have a business model of trying to achieve healing in 3 visits or less. It sounds unreal and illegitimate at first, but its seriously incredible the work they do. I suffered shoulder impingement due to excessive rock climbing and a friend told me about Airrosti. I had been stagnating for a couple months in recovery and had seen 2 orthopedists and they gave me no help so out of desperation I decided to check it out. The Dr. there worked wonders on me, within 2 weeks I could climb hard routes with very little pain. There is a science behind it and its not gypsy, nor do they have the chiropractic model of returning to them forever, they want you healed asap so you dont ever have to return. They do every body part pretty much.

                      I just thought I would say something about Airrosti because it has healed me. They do what the orthopedists cannot, which is surprisingly alot. They are also within departments at major hospitals around Houston where I live which further adds credibility to the outside eye.

                    6. Interesting, Toxins. Not sure what Airrosti can do for food sensitivities, but they’re a long walk from South Dakota. ;-P

                      What do they do? massage?

                    7. Yes, completely unrelated to food allergies! They don’t massage, they do “manual therapy”, which is actually quite painful. The idea is to loosen the connective tissue, improve mobility, and then there is very specific physical therapy prescribed which maintains the work the Dr. did.

                    8. Sounds interestingly dangerous! How can you be sure it was the manipulation and not the physical therapy which did the trick for you? ;-P

                    9. Its definitely a mix of both, immediately after treatment you are instructed to try the physical activity depending on the severity of your injury. The orthopedists I went to gave me PT to do and it really was not helping at all, they couldn’t even diagnose me. Like I said, I would not have believed it myself if I hadn’t experienced it and seen many of my climber friends heal from it. Check out the Airrosti link in my first post for details. This is one of those moments for me that there doesn’t need to be scientific papers to prove its efficacy, the documented 94% patient improval rate and 88% resolution of injuries is enough for me. Most major insurances cover it.

                    10. Visited the website when you first posted it. Guess it’ll be awhile before they open an office in South Dakota. Any nutriceuticals involved?

              3. As ever you are right, Darryl. It’s the whole IGF-1/Akt1/PI3K/mTOR-pathway (and the AMPK branch) we have to keep an eye on. It starts by improving insulin sensitivity in order to optimize postprandial glucose uptake and, as a consequence, minimize insulin signaling in the fasted state. Reducing IGF-1 by protein restiction is just another part of the plan.Then we should make sure to get plenty of all the phytochemicals which inhibit mTOR either directly, or more, often indirectly. It is not unlikely that the combined action of all those phytochemicals at different points on the signaling cascade excert a synergistic inhibitory effect. This could be the reason why plant protein may have a different effect on mTOR activity despite similar levels of leucine: in contrast to animal protein, it comes packed together with those phytochemicals.

            2. We run into problems when we try to isolate the properties of individual nutrients because they react differently depending on the environment they are in. Aminos acids in meats react differently than amino acids in plant life because of there total nutrient makeup.

            3. Exactly! an appropriate size 1 ounce portion of brazil nuts contains 323 mg of leucine. A modest 3 ounce portion of cooked beef contains 2,200 mg of leucine. More importantly, it’s best not to look for exceptions. You will always be able to find them. When you test a claim, look at the big picture. Is a plant-based diet lower in leucine than a diet that is high in animal protein? Yes, the devil is in the details, but the big picture is what is most important.

          2. I used data from the USDA, which reports peanuts at 1.54g of leucine per 100g.

            In terms of food combining, I’d be surprised if that had any effect, as the limiting amino acids in plant foods tend to be methionine and lysine, rather than leucine. That’s part of the reason I’m surprised by the conclusion of this article, as leucine is not one of the amino acids which tends to be proportionately low in plant food sources.

        2. Nutrients in animals sources and plant sources don’t necessarily react the same way in the body. Campbell’s work showed an increased correlation between protein increasing from 10-20% of calories but soy and wheat protein at the same levels did not show the correlation. It is likely the leucine levels in meat are the problem. I love almonds an do eat a lot of them, but I don’t eat peanuts.

              1. That statement would only make sense if the leucine in meat could be shown to be chemically different to the leucine in plants.

                1. Really, that is the only way it would make sense? Why couldn’t it be something in the meat that interact with the leucine that causes leucine to be the problem, and that something might not be in plant based foods, or not to the same level.

                  1. That could be the case, but that would contradict your assertion that it is the leucine in meat protein which causes the problem.

                    You’re conflating two different possibilities:

                    1 – The leucine in meat is the problem.
                    2 – The leucine in meat is not the problem, but something else in meat creates a problem when it interacts with leucine.

                    It is a very important distinction if somebody is assessing the risks of consuming isolated leucine.

                    There are other possibilities which are also relevant when it comes to decision making:

                    3 – Leucine in general causes the problem, but something else in plant based sources of Leucine provides a protective effect.
                    4 – It’s has nothing to do with Leucine, but is caused by another substance or combination of substances.

                    For the research underpinning this article to have practical use, we need to find out which of the possibilities it is.

                    1. I see it this way. Meat protein acts differently in the body than plant protein. Since the leucine in meat may be the issues and not the leucine in plant based foods then it is the leucine in meat that is the problem, Whether it is because of the way it interacts with other substances or not. Our approaches are a bit different, and yours appears to be scientifically driven. Mine is naturally holistically driven. Too much animal protein is destructive to the if it is leucine or not which is the problem, The problem is still meat protein. While people are taking the reductionist approach to issue I am taking the traditional approach (of countries of color) and a meat heavy diet was not part of it,

                    2. I think it might very well have something to do with leucine and very well might be leucine in combination with something else in animal protein that is the culprit. The issues with the reductionist thought is that total effects are attributed to single nutrients where it is likely the nutrient in reaction to other nutrients cause the wider effect. Case in point that it might be leucine in combination with other substances in meat that is the culprit, but that same reaction does not happen or happen as extremely in plant protein. So while it is likely better to warn people about leucine meat consumption, the same conclusion shouldn’t be made for leucine almond consumption.

          1. Hi Aqiyl, If you like OLD wheat grains, have you ever tried Einkorn bread? Einkorn is much older than Kamut and we love the taste made from flour bought online and baked in our Cuisinart bread maker. (no need for expensive bread makers).

        3. Aloha,
          Good point. As a vegetarian for more than 4 decades, I think it important to say to people that leucine is necessary for muscle function and development.Leucine is NEVER a bad thing, its the source(animal) and amounts that are taken in as the result of a typical meat/dairy based diet that’s bad.

  2. Good News. But what about the autophagy and possible neurogenisis that fasting, or near-fasting popularized by Dr. Michael Mosley’s BBC special and 5:2 diet which we have practiced for about 7 months? Is it worth it? Just how many hours of no or few calories suffice to get enough done in the areas of autophagy and possible? likely? neurogneisis?

    Richard Head MD, a friend of ours in Mill Valley, CA and retired radiologist of tremendous energy, a near-vegan, writes a health blog and tries to provide facts to overcome emotional resistance to same. His blog , chapter 25 ( )
    includes this on fasting:

    A lot of work over many years shows that decreasing the amount of calories ingested (30%)will decrease aging. (See previous discussions). However, it is not proven this works in humans. It is known that excess calories, forming fat, will increase aging and chronic disease. One of the chemicals associated with this antiaging is Reservatrol which causes a number of positive effects. It appears the the starving releases this material. It is also found in certain foods. It appears to offer a number of ways to help our health including blocking the division of some cancer cells. Older people with less calorie intake appear to have less memory loss, then those with more caloric intake.

    Recent studies show that the primary mechanism that decrease calories (and vigorous exercise!) work to trigger off signals to increase autophagy (cell repair). This is an important way the body actually destroys various things that are malfunctioning. Without this cleanup the cells will divide and spread the malfunction so that various diseases and aging occur. It appears a certain amount of physical stress is important to make sure our body is healthy. (see chapter on exercise). The fasting time during sleep is very important to allow these functions to happen.

    Recently there has been emphasis on the benefits of fasting. 50 plus years of research has shown that reducing calories by 30% in animals increases their life span and lowers chance of most disease. It has been shown this is due to shift from cell division to cell repair and maintenace. Many genes are activated by the “stress’ of less calories. These allow many important repairs to occur. The results in many lab animals are available, longer life (40%), less cancer, heart disease etc, more neurons , less hypertension and diabetes. .

    “Fasting causes hunger or stress. In response, the body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body,” . “This is important because the fewer fat cells a body has, the less likely it will experience insulin resistance, or diabetes.”
    It seems that one major effect of the fast idea (along with the activation of many protective genes) is the lowering of an important chemical in our bodies Insulin like growth Factor, IGF. This is produced by the liver and is released by Growth Hormone. it is active when we are young and growing but is supposed to lower when we age. It promotes division and cell activity and diminishes repair and maintenance. As we age we need more repair and less new cells. A group in South America, dwarfs, have a gene mutation and have low HG and low IGF. They live long lives, have no cancers or chronic diseases. Besides GH high protein in our diets stimulate IGF.

    A vegan diet is associated with a 50% reduction in IGF in the blood. This diet releases a protein that binds the IGF so it cannot be active. The blood from these patients had 8X the ability to stop cancer cell line growth as regular diets.

    Dr. Michael Mosley has become the “poster boy” of fasting. He did a 5:2 fast plan. two , non consecutive days of fast , out of 7. On the fast days he limited himself to 600 calories. Either one meal or two small meals of 300 calories. He limited his protein. On the “regular” days he ate a normal diet of 1600 to 2000 calories. Again, watched the protein amount ( should not have more then 0.4 grams of protein intake per pound of weight). His results after 5 weeks showed 50% lowering of the IGF, lowered insulin from 110 (pre diabetic) to 90 (normal) and lost 15 lbs. His cholesterol lowered. This is only one case but shows the possibilities.

    It takes about 16 hours for the glycogen stores in the liver to deplete. It is probably this that triggers off the many signals to activate our amazing body pharmacy to repair and recycle. I think the fast should allow at least 18 hours or so of no calories to allow this to happen.

    In chapter 32, Richard writes on
    How and why we age …

    1. Lady you are stressing yourself out over these restriction things.
      Stressing while restricting will cancel each other out if not even worse effects.

      I’m suspecting you are wasting good quality time better spent on the joys of your life. What use is a few extra crippled last months when you could be ice skating right now instead of obcessing over what not to eat?

      Relax, calm down and be merry and you will get your extra years even from that alone! Stop being fat obcessed and live, if not longer.

      If my illnesses tought me anything it is that the quality of life is what is important not so much the duration.

      1. I hate to admit, but you are so right. I often obsess and research, when I should be outside riding my bike or playing pranks on friends

  3. We need to be careful we don’t narrow our focus too much here.

    Given their relative leucine levels one could easily conclude that it is better to eat an egg or two than to much on a handful of soy nuts to satisfy a protein craving. And soy protein isolate, the prime source of protein in many packaged vegetarian products, appears to be worse than going totally carnivore.

    I think more research is needed before the advantages of leucine restriction are emphasized this strongly.

    1. Dr. Greger does not recommend any foods containing soy protein isolate. It raises IGF-1 more than dairy. However, it does not lower IGF-1 binding protein as animal foods tend to do, so one can not say the net effect may be worse than going carnivore.

      PS. You mean omnivore, right? Humans are definitely not obligate carnivores. ;-)

      1. I strongly support the benefits of reducing inflammation. However I would encourage you to research some of the basic tenants of the Zone diet. Fish consumption, for instance, is pretty toxic. Please search on NutritionFacts and you will find studies showing that our fish supply is severely polluted with Industrial contaminants:

        1. Oh I searched and yes I agree the fish and anyone who eats them are Fu_kushima_ed. I am doing the Zone Vegan; except that I still like grass fed organic Chalav Yisroel dairy. Dr Sears likes Vegans. He doesn’t hold by eating fish either, he is into molecularly distilled and very purified fish oil capsules. I think vegan sources of omega 3 work really good. The daily minimum requirement to be ok if you don’t consume any other fats except nuts, seeds, avocado, olives, coconut and small amounts of extra virgin olive oil is 4000mg of omega 3 like from 2 tablespoons ground flax seeds.

        2. The usual kind of fearmongering, concerning all kinds animal products, Dr. Greger often indulges in.

          Epidemiological evidence reigns supreme in this case. There is a clear-cut, positive association between fish consumption and good health.

          You can’t, one the one hand, argue that “nutritionism” is flawed and that you have to regard the whole food (see Collin Campbell’s latest book), and then on the other hand neatly divide fish into omega-3-FA and contaminants, in order to claim that you can get the all the benefits without the purported risks.

          You just can’t know for sure what it is in or about the fish that makes it so healthy. Maybe even the hormetic effects of some contaminants have beneficial health effects? We just don’t know. What we do know beyond any doubt is that regular fish consumption is healthy. Period.

  4. In case my recent post does not make it obvious, I think Dr. Greger and his work are TOPS! The best we have found and we are so very grateful to “our borhter as Aqiyi (bleow) says. What a change he has made in our lives and even his humor and cadences have influenced my public speaking and our conversations on other matters! Thank you,
    Dr. Greger!

  5. Being a vegan is freeing, I have soo many choices of fruit, veggies, and legumes..and YES all the nuts and seeds I want too..not concerned about watching my weight. I’ve dropped 3 dress sizes since becoming vegan a year ago. oh and my blood pressure is back to normal.

    1. I completely agree with Anita. Vegetarianism is liberating. I find people’s dietary habits interesting. We have various noon-time meetings throughout the month which are catered by a mediterranean restaurant. I always order the veggie plate which is a delicious combo of hummus, tabbouleh,bulgur wheat, turnips, falafel, rolled grape leaves and Greek salad. The psychologist, who BTW, is a lymphoma survivor, always orders chicken kebab which also comes with greens, onions, and assorted bell peppers. He has such an aversion to vegetables that he cannot stand the thought of their touching his meat. In the past he would simply shove them to the side of the plate. After a while even the sight of them became repugnant so now, prior each meal, he meticulously scrapes them into the trash.

      1. As an erstwhile life extensionist and avid reader on health issues and subscriber to health newsletters…I see a “conflict” between those who expouse “squaring the curve” by improving and speeding up life and metabolisim in a more immediate fashion vs those focused slowing things down thru metabolic restriction and reducing protein intake. I tend to eat too many calories…but also have a fairly balanced/varied diet…and take many supplements…including resveratrol/COQ10/PPQ.
        The first approach is that of increasing metabolic activity…the second that of reducing it and directing it towards the eventual metabolic “wall of death”? Is it possible to do both?

      2. This is a story about the bad dietary habits of your colleague, not about the benefits of being a vegetarian. You don’t need to be a vegetarian to enjoy your vegetables. You don’t even need to be a vegetarian to eat a predominantly plant-based diet…

    2. Following this logic, every kind of dietary restriction is liberating.

      I’m a flexitarian and I am not concerned at all about weight or blood pressure, too. I don’t need to be “liberated” from my home-made yogurt, parmesan or feta cheese, but rather enjoy the full bounty of Nature and traditional foods. If you are accustomed to a good dietary habits (whole foods, mostly plants, not too much) there is no need for any liberation, as you are consuming all types of food in healthy ratios, just like the traditional “Blue Zone” cultures did for hundreds of years. None of those traditional diets is/was “vegan”, but they all are “plant-based”, deriving most of their calories from plant foods.

      1. Agree with your emphasis on whole foods, Timar, but believe me it’s also liberating to know that one’s meals are not contributing to the torment of other beings, not to mention climate change and other environmental degradation, and abuse of human labor.

        1. Well, I’m with you: eat as much organic, locally grown and produced foods as you can afford. And buy fair trade when it comes to coffee, tea, cocoa or anything imported from developing countries.

          Of course if you have a moral problem with killing animals for food you should follow a vegetarian or vegan diet. I certainly haven’t, as long as the animals are treated and kept well, according to their species needs (i.e. not confining them to a feedlot).

          1. The difficulty is that animal agriculture has more impact on climate change (18%-51%) than all the cars, buses, trucks, trains, ships and airplanes combined (12%).

            The 18% estimate is from the UN report “Livestocks Long Shadow” It was prepared by the FAO, which is the UN agency in charge of promoting among other things the production of animal foods around the world.

            The 51% estimate comes from two climatologist who work for the World Bank They feel the FAO didn’t take all climate impacts into account, such as the loss of carbon sink capability of forests cut down in order to grow more feed.

            Whether you agree with all the conclusions in the World Bank report of not, you can see that livestock is the single largest driver of climate change.

            Pastured meat, dairy and eggs isn’t the answer either. The amount of pasture required is such that we would require every square foot of *all* of North America, Central America and the Northern third of South America just to meet current American demands for these products. (

            Now I know that you have cut back a lot and if everybody did that we might be able to all eat a bit of pastured animal foods without having to turn our entire landmass into pasture. Still if we didn’t eat any, more land could be returned to natural conditions, which are generally better carbon sinks than open grasslands. And we need every bit of help pulling carbon out of the atmosphere that we can get.

            1. Jim: Thank you for explaining the differences between the 18% number and the 51% number. I have seen both of those numbers before and wondered where the discrepancy came in. Thanks! Great post.

  6. I would like to echo Gayle here. Listening to all of your videos has been invaluable in developing a clear communication style for the many curious parties that have questions when confronted with WFPB as an option. My wife and I sell WFPB foods at farmers markets and it means so much to have your videos and blogs to refer to with the frequency we are challenged.

  7. I, too, would love to see some videos about fasting generally, water fasting, juice fasting, and 5:2 fasting. Would love to know if there have been studies about the effects of fasting.

  8. I am so thankful for this information. I have been using food as medicine for almost 3 years after a diagnosis of breast cancer. I was first told it was fine to eat a lot of fish. We are eating mostly plant-based now, thanks to Dr. Greger and Dr. Fuhrman. I can’t thank you enough for this service that you provide to us. I also can’t get enough of your sublime delivery and fabulous voice!

    1. They ate the Okinawan purple sweet potatoes, which are extremely tasty. Its important to note the Okinawans in the prime of their days had the most centenarians per capita.

  9. Advertists consume a lot of soy which is high in Leucine but yet live longer than any other studied group. There must be more to it that we are not seeing.

    1. Soy protein is not high in leucine, its about even with bean protein, rice protein, meat protein, and even kale protein. I’m at a loss as to how the good doctor blew the interpretation of the data so bad this time, except to think that everyone has bad days now and then. The possible bad implications of excess leucine would be relevant to excess protein intake, not just animal protein. The graph that showed the difference in leucine content was based on 100 gram servings. As the leucine content of the food item protein fractions was effectively equal across the board, all the graph showed was relative protein content. Granted, with meat and beans its easier to consume too much protein, but that doesnt make either bad, it just makes wisdom and self control that much better.

    1. They’re less likely to suffer from hemochromatosis because of their monthly menses. This puts them in good stead for old age. Men however can get the same protection be avoiding the heme iron found in animal products or by donating blood.

    2. Around 73% of the difference is due to lifestyle choices:

      Life expectancy Men Women Difference
      Californians 73.9 79.5 5.6
      Adventists 81.2 83.9 2.7
      Vegetarian Adventists 83.3 85.7 2.4
      Healthy* Adventists 87.0 88.5 1.5

      * never-smoking, vegetarian, exercise ≥ 3 times weekly, eat nuts ≥ 4 times weekly, BMI < 25.90 (males) or <25.20 (females).

  10. Great video, ground-breaking in fact. I can skip soy except some very occasional edamame, which is soon tiring, like everything else plant-based that I consume. My current diet is mostly plant-based, no dairy, little if any meat, and I add juiced beets, kale, lemons, carrots, celery, parsely to a blended salad with spinach and romaine, RAW Life protein powder and ground flax seed daily. This is a high nitric oxide dietary formula. Over age 40 we need more beets and spinach to supplement for loss of ability to convert arginine to nitric oxide.

  11. Is there a list of Leucine relative to a standardized protein level? For example mg/10 grams of protein from beef, soy, milk, beans, etc. As other have mentioned, mg/100kg serving can be misleading because the total amount of protein is different between foods in this measurement.

    1. Roll your own. Dr. William Harris converted the USDA food database to an Excel spreadsheet. Its not at all difficult to enter a “=cell/cell” formula as an entry and copy it through a column to get g leucine per g protein, leucine per kcal, or my favorites like leucine/lysine or methionine/lysine. For those who don’t have a copy of Excel, there are fine (in some respects, superior) open source software like OpenOffice which works fine.

      1. Darryl, great suggestion. I have been using Dr. Harris’s spreadsheet for some time now. Dr. Harris is a big proponent of sorting foods by nutrient/calorie ratio, and to summarize: animal foods and soy isolates have about 2 grams leucine per 100 calories while beans and tofu have about half a gram leucine per 100 calories, which is the same proportions Dr. Greger shows in this video.

      2. I took your advice and I quickly did make a spreadsheet that I can share with everyone. I choose some common foods for contrast and added a cell of the % of the protein content derived from Leucine. The results surprised me. Of course total protein content is also very important as that determines the overall “leucine load” but just looking at the percent derived from leucine is interesting as well.

        1. Aaron: It took me a while to get to your post, but I’m glad I took a moment to check it out. Your spreadsheet is great! Thanks for sharing!

  12. Keep eating plant foods. Today at lunch they served cookies, various sandwiches (including so-called vegetarian ones containing egg salad and feta cheese) and I just ate three plates of fruits and veggies (and brought my own vegan sandwich). I looked around the room and saw several people manifesting early obesity and advanced aging. It was interesting to correlate what people ate with how they looked. I will continue to eat as much plant-based food as I want until I am full and not worry too much about macronutrient distributions or total caloric intake, relying on my own sense of satiety and intrinsically filling fiber-dense plant foods to get me through. Caloric restriction is great if you are overweight but if not, then you just end up tired and osteopenic and too fagged to exercise.

    1. I looked around the room and saw several people manifesting early obesity and advanced aging. It was interesting to correlate what people ate with how they looked.

      Every single time I shop for groceries.

      1. Me too. But from my observations it seems hardly related to the amount of animal products in the shopping cart, but rather to the amount of processed, refined and manufactured food (or rather “edible foodlike substances, as Michael Pollan put it).

        1. Hi Timar,
          I see you enjoy Michael Pollan’s books. I too read them as them were published and practiced “mostly plants” idea. Then I read two books written by vegan athletes who talked about recovering faster after long runs. I had already been enjoying Dr Greger’s website so the books and these videos made the switch easy. I didn’t eat processed foods before my switch. Actually I can’t remember a time when I did. Also primarily organic since it was a available.

          But here is the weird part. Since going vegan I am taking less thyroid medication every time I go in to have it checked. I have been on this medication for 18 years with no fluctuations before.

          And before you say

            1. I can’t agree more. Even after 2 years of giving up the meat/fish my thyroid med is still going down. So strange. I wonder if anyone else has had a similar response?

            2. No, it isn’t. It is a great example of how we are all individuals, with our own, individual health concerns and dietary requirements ;)

          1. It’s great that you have found a diet that works for you and that helps to keep your thyroid problems in check! I’m doing fine on my flexitarian diet too, with excellent biomarkers and no health issues.

            However, I have seen a lot of reports similar to yours, but many of them (pretty much half, I guess) are just the other way around: people who have followed a plant-based diet for years experienced health benefits when they included some animal products.

            I guess they are all right. There are a myriad of reasons why people do better eating or avoding certain foods. For some people, animal protein may contribute to low-level inflamation, for other people it may have beneficial effects. Some people get all their vitamin A from plant foods, while a few people lack the enzyme that splits beta-carotene into retinol and need preformed vitamin A to feel healthy.

            There’s a vast biochemical individuality related to nutrition, which we only have begun to understand on a genetic level (sometimes refered to as nutrigenetics). This is why there is no optimum diet for everyone beyond the basic rules Micheal Pollan described so aptly. We all need to start from there and figure out for ourselves.

  13. “Autophagy: It’s what’s for dinner.”
    Great set of videos, Dr. G. Your ability to present complex information in a digestible format is second to none, and your choice of topics continues to raise my game. As an added bonus, you provide the source material which-in this case-is enough for PBS to start a new series called, “This Old Mouse.”

  14. Thank you Dr Greger. Your work helps to keep my husband and I on the WFPB diet. And we try to spread the word despite the tomato effect, the nutritional advice of mainstream media and the latest fad diet.

  15. A Plant based diet is great! Large portions, nutritionally dense and lower in calories than a meat based diet. If I ate as much meat as i do veggies I’d be huge.

  16. Question to Dr Greger: Soy products like “fake meats” containing Isolated soy protein is a no go then? I’ve read that the isolated soy protein actually raises IGF1-levels more than cow’s milk. (Starch Solution by Dr John Mcdougall)

  17. watch your videos incessantly … (fighting cancer) … watching this one, overcome with gratitude … Thank you SO much for your work… what an amazing, incredible gift… I NEED the science to have the discipline to choose what is healthy.

  18. I am all in on the plant based diet. But the other side of it is the side effect of a diet high in oxalates. Oxalates come in the darker vegetables, beans and nuts which I have been living on for several years now. I developed a very painful condition called vulvadynia. I am now taking calcium citrate and weaning myself from those wonderfully “healthy” foods including whole wheat and gluten and soy and am experiencing tremendous relief. What’s a health conscious eater to do?

  19. Boy am I confused… O.K. We’ve had some videos regarding adequate protein intake. The scientific mantra is that the best ratio is 0.8-1.2 grams of protein per kg of optimal body weight. Nevertheless, the Doc mentioned a study that criticized this concept, saying that we should maybe strive more for 1.2 gr/kg. Do we scrap this? Because at 10% protein, I would never reach the 90 gr of protein per day. I need answers because A) for years I have tried to pack as much protein as I can in my meals, which can be difficult if you consume a vegan diet; B) I am very active physically.

  20. I started using Cronometer to track my plant-based nutritional profile… My fiber intake is almost double the minimum. No problem there. However, my total protein intake is 215% over the RDV. But the lowest component is methionine at 105%. So, how can I lower the total without bringing this one lower as well and breaking below the minimum?

  21. The table shows Okinawans eat 69% of their calories from sweet potatoes and only 3% from vegetables. Perhaps other routes than leafy greens to get to the same longevity.

    1. I consider sweet potatoes part vegetable, especially since Okinawan sweet potatoes are a deep purple color. The antioxidant content of sweet potatoes are very high, as Dr. greger will discuss in a near future video.

  22. Good to know! Of course nobody else is going to admit that limiting protein intake is just as effective for longevity as calorie restriction. Some would just rather starve. As a vegan, I’m never starving.. always pigging out and wondering how I manage to keep the weight off :-)

  23. Gotta say that most places, when you read the comments, they are riddled with disrespectful and ill informed people. This is the first time I have seen constructive discussion taking place. Brilliant.

    1. Brenda: Thank you very much for this nice feedback. We don’t always succeed, but we try very hard at NutrtionFacts to make the comments section a pleasant and helpful community for everyone. Thanks for noticing.

  24. In looking for ways to increase my longevity, I have been made aware of the potential benefit of caloric restriction and/or intermittent fasting. BCAA supplements (typically a mixture of leucine, isoleucine, and valine) are supposed to be helpful for retaining muscle while fasting.

    Of all the poking around the internet to learn about BCAA benefits/risks, the most scientifically-referenced-looking piece of seconday literature was at:

    Take note of the paragraph near the end with the heading “#10: BCAAs Correlate With Longevity and Are Therapeutic”.

    Side note: I can’t remember my source, but I was informed that Okinawans consume pork fairly regularly. Coincidentally I don’t enjoy eating pork but do enjoy eating the other Okinawan staple food – sweet potato.

    1. re: “I was informed that Okinawans consume pork fairly regularly.” I suppose that could be technically true if frequency is an issue and is well defined, but it is very misleading. My understanding is that historically, traditional Okinwan’s ate 4% animal products. This includes all dairy, fish and other meats. Even if pork were part of that 4%, it would not be a significant part of their diet.

      Sweet potatoes, on the other hand, was something like 70% (if I remember correctly). So, good thing you like those sweet potatos!

      1. Speaking of Okinawan sweet potatoes, every November they are in most major grocery stores for a short period of time, so save the date and stock up when you can!

  25. Leucine and Weight Loss

    Researchers have looked at the response of adipocytes to leucine deprivation (taking leucine from the diet). Much of the following is based on animal research, as it is difficult to justify refusing human subjects an essential micronutrient. When mice were provided with a leucine-depleted diet, fat loss was greater. Lipolysis, the release of stored fat, was increased; lipogenic enzymes, including fatty acid synthase, were reduced; and uncoupling protein was increased in brown fat, which results in burning more fat for heat production.How much weight loss was experienced by the leucine-deprived mice, and how did it occur? The leucine deprived mice lost about 15 percent body mass, related in part to a near equivalent reduction in daily calorie intake (15 percent). However, an increase in energy expenditure was also present; typically, when energy intake goes down, so does energy expenditure, as the body tries to conserve in an environment of limited resources (food).

    A separate group of mice that was fed an equal number of calories, containing a normal leucine content, lost only 5 percent of bodyweight. Of the weight lost, the leucine-deprived mice lost a significant amount from the abdominal fat depot, roughly 40 percent; the leucine-fed mice fed the same number of calories did not lose a significant amount of abdominal fat. Total body fat was similarly affected.

    Markers of metabolism supported the hypothesis that energy expenditure was increased in leucine deprived mice. Serum (blood) norepinephrine and T3 were elevated in the leucine-deprived group; body temperature was elevated; and brown fat was activated, turning fat calories into heat as opposed to energy; the leucine-deprived mice managed to burn more calories, specifically fat for calories, without any increase in physical activity.

    The net result was a marked 42 percent decrease in white adipose (the storage form of fat) volume.This was accomplished by increasing the activity of hormones involved in breaking down the stored fat, and burning much of that fat in the adipocyte. A 200 percent increase in PPAR-alpha was recorded, along with increases in the fat-burning enzymes stimulated by PPAR-alpha protein. As more fat was being lost, less was being made. One enzyme important to storing fat, called fatty acid synthase, was suppressed over 30 percent in white, adipose tissue. A prior study by the same authors showed a similar effect on suppressing fatty acid synthase in the liver of leucine-deprived mice.

    Of course, bodybuilders are scoffing at the notion, regardless of fat loss, because everyone knows depriving the body of the essential branched-chain amino acid leucine would lead to catastrophic losses in lean mass… right?

    Actually, the leucine-deprived mice showed no difference in lean mass, from either the control mice or those that were restricted to the same number of (reduced) calories consumed by the leucine-deprived mice. The control mice are normal mice, eating as much as they will; the pair-fed mice are normal mice eating a normal diet, but only as much as the leucine-deprived mice chose to eat; the leucine deprived mice ate as much as they wanted, but they chose to eat 15 percent less than the control mice, (thus, the pair-fed also ate 15 percent less than control, but it was a diet that contained a normal amount of leucine).

    Pair-fed mice lost only 5 percent of bodyweight, and their lean mass did not change appreciably; leucine deprived mice lost 15 percent of body-weight, and their lean mass was the same as the control mice, and unchanged.There were no strength or endurance challenges, but when one considers that the mice lost 50 percent of abdominal fat, 15 percent of bodyweight, and had no loss of lean mass, that is incredible.

  26. Dr. Greger,

    It seems that both signaling muscle protein synthesis (MPS) and aging prematurely (as discussed in this and previous video) involve the leucine/mTOR connection. Do you think, or is there research, that long life and building muscle mass are fundamentally opposed goals based on how our body is designed? Also, do you think, or is there research, that the mTOR theory of aging and leucine acting as a trigger could be meat/animal-protein specific? In other words, could eating leucine-rich plant foods in order to signal MPS still provide longevity benefits as well as muscle-building benefits? Kind of similar to the whole nitrate/nitrite conundrum where plant-sourced nitrates (from beets and arugula) get metabolized in the stomach and re-sent to the mouth where, instead of becoming carcinogenic nitrosamines (as is what happens when you consume nitrates from meat), they become NO and increase our oxygen efficiency. This seems plausible to me since you’ve praised pumpkins seeds (which are relatively high in leucine) in some past videos: ( specifically the mineral content and serotonin boosting effect.

    Research papers describing MPS and leucine signaling:

    1. Super important questions especially for body builders who may want to follow a more plant-based diet. I think you are onto something. Plant-based diets have been shown to work successfully in athletes, but over-consuming protein and working your muscles day in day out to me seems like there could be a downside. I know many plant-based athletes who refrain from large supplements and stick to whole foods. Let me research this a bit more and read your studies. Forgive my delay I will answer you as best as possible. Do you want my links to plant-based athletic research? Thanks, Michael

      1. Thanks for the reply, Joseph!

        I would love to review what research you can share. From what I have read, relating to popular plant-based athletes, it seems the main focus has been on endurance athletes rather than athletes concerned with hypertrophy. Of the anecdotal plant-based bodybuilders stories that I’ve read, they are relatively recent converts to a PB diet (i.e. they were winning athletes with large muscles before converting, and have been able to retain their mass and increase their recovery once switching diets). My question is more about building muscle mass while on a PB diet which is something that I haven’t found much research on.

        Also as I stated above, I am very fascinated by the possibility that leucine/mTOR could be an analogue to the nitrate/nitrosamine/NO connection — that plants cause benefit where meat causes harm.

  27. Dr Greger,

    I love your videos. However, I do not believe that you always present the facts as straight forward and objectively as they could be. From your video, one would believe that chicken has more leucine than kale. However, the amount of leucine per gram of protein from chicken is very close to the amount of leucine per gram of protein in kale. Yes, there is more protein in 3 oz of chicken than 3 oz of kale, but per gram of protein. leucine content is very similar.

    So the objective seems more to limit total protein consumption rather than from what the protein is derived. Obviously, avoiding animal products is a great way to reduce total protein consumption, but I believe most people from this video would believe that 60 grams of protein from animal products has substantaily more leucine than 60 grams of protein from navy beans. According to nutrition facts and analysis, 60 grams of chicken protein has 4200 mg of leucine and 60 grams of protein from navy beans has 5100 mg of leucine. Clearly, that is different than what anyone watching this video would believe.

    My concern is that I wonder how many other video analyses also have such bias toward veganism.

    1. The difference is that with a diet centered around animal products, it is difficult to get a day’s worth of calories without getting excess protein. Can you devise a diet where a substantial percentage of total calories comes from animal products that A) has the same number of grams of protein and B) has the same number of calories as a WFPB without resorting to refined sugars and oils to up the calories without any additional protein.

      The frequent knock on WFPB diets is that they “lack” protein. And relative to a meat-centric diet, it does. But that also means that eating a WFPB diet it is relatively easy to get enough calories to maintain weight while still keeping protein consumption to that required for body maintenance (~5-10% of total calories). Not covered in this video, but I would be willing to bet that an increase in TOR signalling starts at the level of protein required for maintenance. It would be very interesting to know if luciene in protein up to the maintenance level has any effect on TOR.

      But your point is well taken. A lot of people eating a WFPB worry about getting “enough” protein, and so devote particular attention to eating plant foods particularly high in protein, like beans, or even going to the extreme of eating isolated protein supplements like pea protein to make sure that they “get enough”. I know that I did at least initially. But I don’t any more because I demonstrated to myself that a given amount of just about any whole plant food, save fruits, supplies the same or higher percentage of daily protein requirements than that same amount contributes towards daily calorie requirements. The same also applies to each of the essential amino acids as to protein overall. The bottom line is that if you eat enough calories, protein just takes care of itself. No need to make any special effort what so ever. And with the information in this video, it might be wise to actually do a bit of the reverse and focus a little extra on the lower protein foods like rice, wheat, potatoes and a little less on high protein foods like legumes. And we should eat greens because they are just jammed full of nutrients rather than the fact that 40-50% of the calories (even though the number of calories is very modest) come from protein.

      1. I agree with what you said. I just wanted to point out that for a fixed amount of grams of protein either from plants or animal, leucine content is about the same so the only way to really limit leucine is to limit protein. However, methionine levels are much lower in plant based protein rather animal based protein so a WFPB is the only way to go.

  28. Your article states that, “To reach the leucine intake provided by dairy or meat, we’d have to eat nine pounds of cabbage—about four big heads—or 100 apples. These calculations exemplify the extreme differences in leucine amounts provided by a conventional diet in comparison to a plant-based diet.”

    Why not present a more protein-equivalent comparison like beans, rather than an extreme example of vegetarian foods that contain very little protein? This type of apples-to-oranges comparison leads me to question the objectivity of your reporting.

    1. Hi Caroline. There is a lot of discussion about leucine content in plant foods on the latests blog today about TOR. See if that thread helps answer your questions? I’m to happy to help answer any additional questions you have and agree that maybe comparing beans and plant sources that tend to be high in leucine is more appropriate. Thanks for your comment.

  29. Great video and comments but I thought that caloric restriction as a mechanism for increasing longevity in primates has been discredited in recent studies such as . I don’t think this negates Dr. Greger’s points/conclusions in this video but I have noticed that he asserts that “the benefits of caloric restriction on health and aging has been clearly demonstrated” (i’m assuming he means in humans) in several videos and blog posts including today’s (15June 2015) post “Living Longer by Reducing Leucine Intake”. Again, I’m not debating the good doctor’s conclusions but just wondering why he continues to make assertions that i thought were essentially disproven. Also wondering why this point has not been brought up in any of the numerous comments for this video. Please enlighten me :).

    1. A later (2014) study in primates confirmed the benefits of calorie restriction. It suggested that, in the 2012 study you refer to, the control group of monkeys was also effectively undergoing calorie restriction which explains why there was no benefit found in that study.
      “Here we show that CR significantly improves age-related and all-cause survival in monkeys on a long-term ~30% restricted diet since young adulthood. These data contrast with observations in the 2012 NIA intramural study report, where a difference in survival was not detected between control-fed and CR monkeys. A comparison of body weight of control animals from both studies with each other, and against data collected in a multi-centred relational database of primate ageing, suggests that the NIA control monkeys were effectively undergoing CR. Our data indicate that the benefits of CR on ageing are conserved in primates.”

  30. I was watching this video while my 11 year old daughter is sitting next engaged in something else and seemingly not paying listening. Until she responds to the question, “So where is luecine found?” Her response, “McDonald’s.” :) I think her passive nurtion facts education is having a positive effect. I’ll continue to keep the volume turned up.

  31. Paul Jaminet writes “As I mentioned yesterday, I have a Google
    Alert for centenarian stories and have been reading about them for
    some time. One thing I’ve found is that most centenarians don’t
    seem to think very much about their diets (which protects them from
    the food pyramid!), but supercentenarians tend to be very picky about
    what they eat. Supercentenarian diets come in two basic
    1) Calorie-restriction and
    intermittent fasting.
    2) High (saturated and
    monounsaturated) fat low-carb diets.”
    Is that last bit about the “two flavors” true? I believe you
    recommend strongly against saturated fat and do not say we should
    restrict calories, right? Your video says it makes more sense to restrict proteins, especially animal proteins containing high levels of leucine. Therefore Jaminet must be mistaken, isn’t
    he? What about intermittent fasting—doesn’t it lead to autophagy,
    which can be a good thing? Also can you comment generally about supercentenarians please?
    –john tiffany
    Information From:

  32. The problem I have with this video is Dr. Greger fails to mention that Leucine is an essential amino acid, meaning that the human body cannot synthesize it, and it therefore must be ingested to live. Moreover the highest quanity of Leucine per gram of food source is soy beans, followed by beef, peanuts, fish, wheat germ, almonds and chicken.
    It seems to me limiting your Leucine levels would be dangerous and difficult.

    1. CommanderBill3: The following page has a nice bar graph showing the 1) essential amino acids, 2) how much we need of each acid, 3) how much we get from common plant foods. (Scroll down a bit)

      It’s not a matter of getting the highest quantity of any particular amino acid. The issue is how to cover our dietary needs. It looks to me like common plant foods (even ice berg lettuce!) cover our essential protein needs just fine.

      1. I think your missing my point. The video suggested that we could live a longer life by limiting our dietary Leucine by reduction or elimination of eating meat. What the video failed to mention is Leucine is essential and it is in a great deal of foods besides meats. It would be very difficult to limit it’s consumption. Moreover you’ll probably find some one that will try to eliminate for their diet in its entirity with a fatal result.

        1. CommanderBill3: Thank you for your clarification. I feel I had addressed your points, but your reply makes it clear that I need to be more direct with my wording.

          re: “Moreover you’ll probably find some one that will try to eliminate for their diet in its entirity with a fatal result.” Please review the link I provided above. Repeated here for your convenience:
          The bar graph in the middle of the page makes it clear that it would be impossible to eliminate leucine for anyone eating the diet recommended on this site. They couldn’t do it even if they tried. Your concern is not justified.

          re: “What the video failed to mention is Leucine is essential…” That’s because the point of the video is to limit foods that have excessive amounts of leucine, not to eliminate leucine.

          re: “…and it is in a great deal of foods besides meats.” As mentioned above, leucine isn’t just in “a great deal of foods besides meats”. To my knowledge, leucine is in all whole foods besides meat. And as you point out, it is very good that all whole plant foods have some leucine in them. We just don’t want too much leucine. This point is getting at the concept: “the dose makes the poison.”

          The video is not telling anyone to eliminate leucine. In fact, to my knowledge, that’s impossible on a whole plant food based diet. So, there’s no need to explain that leucine is essential or worry that people will cut out leucine from their diet. Instead, people need to know which foods in general have a whole lot of leucine compared to other foods so that healthier food choices can be made. Following a general practice of choosing foods lower in leucine is how someone can end up with the healthy amounts of leucine.

          From the video: “…just cutting down on leucine may be nearly as effective as cutting down on all protein. So where is leucine found? Predominantly animal foods: eggs, dairy, and meat, including chicken and fish, whereas plant foods have much less: fruits, vegetables, grains, and beans.” Dr. Greger is giving us simple rules of thumb to follow in order to get the right amount of leucine in the end. The video is not telling anyone to precisely measure leucine or worry about eating a few almonds now and then. But if your diet contains lots of meat, dairy and eggs, then you may have a problem…

          I hope this reply is more clear.

  33. Are there any studies on fasting? This seems to be a fad now, for ageing and weight loss. What’s more effective–fasting for 3-5 days once a month, 2 days a week, or 16 hours a day. It’s struck that fasting may be a factor as one very strong element of the traditional Cretan diet, albeit never mentioned, is the Orthodox fast which was still a very strong element when Ancel Keys conducted his study and is also very strong among older Ikarians whose longevity has been referenced quite a bit recently.

  34. I heard about a study finding that elderly people consuming above average amounts of protein showed the least amount of cognitive decline. Does anyone have a reference for the study?

  35. Although leucine does indeed seem to activate TOR, it along with the other branched-chain amino acids isoleucine and valine seem to have some life extending benefits such as activating sirtuins, encouraging mitochondrial replication, and bolstering our internal antioxidant systems as detailed in the following article:

    Branched-chain amino acids, mitochondrial biogenesis, and healthspan: an evolutionary perspective.

    I spent a few hours reading and highlighting this article. At this time, I think leucine is fine and perhaps even desirable. According to the American College of Sports Medicine position stand on nutrition, muscle protein synthesis is improved after strength training by consuming meals containing something like 3-4g of leucine every 3-5 hours.

    Right now, the amino acid I try to limit is methionine because it is substrate for overproduction of homocysteine, which is in turn a risk factor for heart disease.

  36. I just checked the Bragg liquid animos I use as an alternative to soy sauce and it says it has both leucine and methionine animos. Do plant based (soy) sources of these amino acids have the same effect as animal product sources?

    1. leucine and methionine are found in lots of plant foods but animal products contain extremely high amounts in comparison. Consuming soy regularly is linked to health benefits including preventing breast cancer and being good for skin quality, but soy protein, unlike other plant proteins, is similar to animal protein so it can have similar effects but only if you’re eating MASS amounts of it. Dr. Greger has at least a couple videos on that.

    2. Hi, Inches. I am Christine, a NF volunteer moderator. First of all, I am not sure why you would use Bragg’s Liquid Aminos as a substitute for soy sauce, because it is not very different from soy sauce, particularly tamari. Second, I do not think the video above is advocating for eliminating leucine and methionine from the diet entirely. They are, after all, essential amino acids, meaning that the human body needs them, and cannot make them in sufficient quantities. Plant-based foods tend to have less of these amino acids than animal-derived foods. They are likely to meet nutritional needs without exceeding them. It seems to be the excess that causes problems. I hope that helps!

  37. I think I understand the strategy of restricting leucine to avoid TOR, but if I’m wanting to maximize the benefits of autophagy, is there some benefit to be gained from skipping breakfast and maybe lunch and condense my plant based meal(s) to later in the day? I’ve tried it a few times and sort of like how it feels to have an empty stomach. It seems a little easier for me to skip meals than to eat lightly. BTW – even though n=1 is a flaw, have you seen Hershel Walker lately? Life long 1 meal a day guy in his mid fifties looking like his mid thirties.
    PS – I guess everyone saw Nobel Prize awarded recently for work on autophagy.

    1. Hi Chanjw,

      I am a volunteer NF moderator and am happy to help. Intermittent fasting does decrease IGF-1 and has been shown to slow down the aging process and reduce some cancer risks Most intermittment fasting benefits are seen from fasting 16-18 hrs per day. Of course, it is always advised to talk to your healthcare practitioner first before long periods of fasting in order to prevent any drops in blood sugar that may be problematic. I hope this helps!

  38. Hi, eqbal oughtought. I am Christine, a NF volunteer moderator. Tofu may appear to have a lot of leucine if you look at the content per 100 calories, as you have, because tofu is not a calorie-dense food. If you compare with other foods per 100 grams, which is a generous 1/2 cup serving and only 78 kcal, the leucine content is less than a gram.
    Compare that to 100g of whole, poached egg, which provides 143 kcal and more than a gram of leucine.
    We are not suggesting that people completely eliminate leucine from their diets, as it is an essential amino acid. This means that the human body needs it, but cannot make enough of it. I think the problems arise when people get too much, which is more likely with animal-derived foods. Foods from plant sources generally have lower leucine contents than foods derived from animals. I hope that helps!

  39. I need help!! I’ve been lurking on this site for about a year. Finally bit the bullet about 2 months ago and went vegan (starch solution style). I feel great. Almost everything in my life is better on this way of eating.

    One thing I’ve noticed in the past week or so though, is that my face, neck and back are breaking out in zits in a way they haven’t since high school (I’m 33). Also my face/neck skin suddenly feels very thin. I know this is happening because every day at work I sit with my elbow on the desk, hand on under my chin or on my cheek. For the past week, my skin feels like tissue paper. When I scratch my eye, my skin pulls and feels like it’s going to tear. One other thing that might be happening but I’m not sure, is it seems like the area around my eyes looks hollow, like I’ve lost fat or skin thickness there.

    This is very alarming! In itself weird, and scary to think I might be doing some other unseen damage to my body if I don’t fix this. I’ve looked it up and it sounds like the culprits MIGHT be that my diet is too low in either protein or fat. Does anyone have any experience with this? Any advice on how to change my diet to better support skin elasticity and skin robustness? I’ll be sad if I have to abandoned this way of eating since it has so many other benefits. Sorry for the long post. Thanks in advance for any advice!

    1. Hi L King, thanks for your question. I am one of the volunteers at the site. I don’t know your daily food intake and activity level. Also your age and life style and level of stress in your day to day life. I could suggest writing your food dairy and activity and emotional journal to see if you are including the right amount of food intake and activity and good steps for relaxation. Also vitamin D levels is known to be important in skin protection .

      The good fats that are recommended can be found in avocado, nuts say minimum of 10 gram per day which would be for example up to 10 almonds or up to six cashew nuts or 5 walnuts or pecans and also two to three Brazil nuts per day or mixture of all. Please know that your nuts intake can be higher depending on the total food intake.
      Seeds such as chia seeds could be very good for skin. Of course we know the benefits of fruits and vegetables and their polyphenols and antioxident protection. Certain ones are particularly high in antioxidants that can protect your skin, including blueberries, green leafy vegetables, and yellow- or orange-colored fruits and vegetables. Fruits and vegetables are also a good source of water, which also helps maintain skin health and elasticity. Consume a variety of fruits and vegetables to provide a variety of nutrients from different sources. Which I assume as a plant base diet you shall have adequate amount. Other issues could be reactivity to certain food, environmental trigger? Please refer to below refernces. As for protein source in plant based diet plenty of diffrent beans, lentils, soy if you can tolerate it and nuts and seeds also have good source of proteins. Meanwhile use of essential oil as topical is good for skin. I personally use them. I hope these informations of any use to you.

      Top 4 Essential Oils for Acne
      Vitamin D and its role in psoriasis: An overview of the dermatologist and nutritionist.

      Flax Seeds for Sensitive Skin

      1. Thank you for all the info! I searched this site for relevant topics earlier and hadn’t found the Flax Seeds video, so I will watch that now. I will start eating flax seeds (I have some in my freezer, just hadn’t been eating them regularly). My diet is usually this: oatmeal with almond milk for breakfast, or shredded wheat with banana, etc. Lunch this week has been a mix of sorghum, rice, onions, and eggplant. For dinner I will eat a salad with nutritional yeast and then some other veggies with tofu or a sweet potato. My fat intake has been very low, I will add in some more nuts and seeds. Hopefully that helps!

        I started a regimen of tanning in a UVB ray-only tanning bed since watching a video about it here. I feel better since I started doing this. I only go for a few minutes at a time maybe 2-3 times a week. I keep my face covered when I do this, since it is getting sun the rest of the time.

        I exercise 5 or more times a week. Intense cardio and weight lifting for about 45 mins – 1 hour each time.

        I have been mildly stressed with my job, etc. so I will try some strategies to reduce that.

        Thank you for the info on the essential oils. I will try those as well.

        Thank you for all these suggestions!

  40. Hi everyone, I have a question that is probably relevant for people trying to build muscle at the gym. Clearly, protein and hence amino acid intake as well as excess calories are needed to build more muscle mass. Is consuming excess calories and protein not really compatible with longevity?

    This videos seems to emphasize leucine as a particular culprit. I was under the impression that leucine was also important in maintaining muscle mass, as briefly mention in what I thought to be a helpful video on youtube:

    Following this, would the consumption of whey protein supplements be harmful?

    Please let me know what you think!



  41. Hi Par,

    I am a volunteer for Dr. Greger. Thanks so much for your question.

    This is a very difficult topic to answer, mostly because the scientific community does not know the answer. Here’s one video Dr. Greger has done on plant-based diets and muscle building.

    Consumption of excess calories and protein may not be detrimental to longevity IF they are plant-based calories and protein. Leucine can be very easily provided sufficiently from a plant-based diet that is balanced, especially with soybeans, nuts, and seeds.

    I would not recommend the use of any protein powder, since it is an extremely processed food. On top of that, whey is an animal protein, and likely is not healthful. Adequate protein should be able to be achieved through a balanced plant-based diet.

    Fear of protein inadequacy has been created and perpetuated by the animal agriculture industry, as well as the supplement industry, because it makes them money in the end.

    I hope this helps, and best of luck on your health journey!

  42. Great video. This makes me feel a lot better about depriving myself of meat, dairy, milk, eggs, and cheese. Now, I have even more knowledge and reason to stay clean.

  43. But why not do both? I’ve been using plant based together with intermittent fasting. Dr. Gregor is very binary when it comes to caloric restriction vs plant based. I have found it is very easy to do. Those I’ve encouraged to adopt this way of eating have also found it extremely easy. It is only difficult initially mostly because we are conditioned to eat nonstop. This is not true hunger. So many people think they have blood sugar issues which usually goes away with a bit of intermittent fasting. I recommend eating in a continuous 5 hour window. So simple. Try it for 3 months. I guarantee you will feel the best you ever have. Combine it with plant based eating FTW.

    1. I agree. I have been doing a vegan IF for the last 3 weeks with some good progress on weight loss end. I also have some neuropathy in my feet as well as some sinus issues I am hoping to clear or make progress on at least. My wife is doing this with me, vegans both for the last 6 years but fat vegans. We are both doing 4 hour window with me likely to just drop to a 2 hour window. Perhaps a few 36 to 42 hour fasts thrown in. As humans we evolved fasting or we would have likely died off years ago. A vegan diet and IF might just be the ticket to the 1000’s of fat vegans such as myself.

  44. I recently realized that extreme caloric restriction with all the negative side effects may not be the best approach. I noticed that as I was eating, I would continue until I felt comfortably full. However, this was long after my hunger pangs had subsided. So instead I changed my habits and chose to become more intentional about stopping my meal once I was no longer hungry rather than waiting to feel comfortably full. I figured that my body’s natural systems had kicked in and that it would not go into nutritional panic mode because the hunger switch was turned off. Over the course of a year I have gradually dropped about 40 pounds from a high of 200. I was 135 in college. I do not feel deprived and can eat many things I enjoy. I do try to get enough water and fiber and plant based nutrition as well, but don’t overdo it. I hope this helps some who may be struggling to have a different gradual way to reach their goal and drop weight naturally.

  45. I have a couple of things to ask. If we starve ourselves like by eating one meal a day, our body won’t be able to produce enough energy from glucose
    because we don’t get it in the first place right? Plus, instead of making nergy from what eat, our body tend to creat something called Keto body? in our
    Kidneys, and that process severely damages our Kidneys and we lose something else like culcium and muscle due to the lack of energy source, one guy who calls himself a doctor siad. Is all this true? Any supporting articles or evidences?

    Thanks in advance

  46. Which vegans do you think live longer or will be healthier? Ones who eat fruits and vegetables three times a day or those who constantly starve themselves for a short period of time. It’s hard for me to believe that fasting stimulates your ability of concentration or clearance of bad stuff because they won’t eat or drink any. How come your body manage to function properly with no nutrients in the first place?

    1. The ones who are on calorie restriction, hands down. This actually has been extensively researched with both lab animals and humans. Dr Roy Walford, MD even wrote a book about it called The Anti Ageing Plan that refers to much of this research. The calorie restricted lab animals all lived longer. The people all saw biomarkers improve, cholesterol, etc…

      Also the human body HAS nutrients but like a car you do not have to keep a gas pump nozzle emptying in the gas-hole as you drive around. The car and human body hold excessive amounts of fuel from its gorge-fest at the gas station/ dinner table. The human body has the ability to break down itself and live for days without food, which is why we do not need to eat 24/7.

  47. Why the sudden about-face on recommendation strategy? Dr. Greger has never before shied away from recommending things that aren’t feasible for the general population, and caloric restriction is perhaps other than diet the thing we have the strongest evidence for, it seems like he should recommend it, even if most people are likely not to do it. It seems like he’s falling into the same paternal trap that typical dietary and exercise recommenders fall into.

    1. If the science is good, and it looks promising, perhaps a Whole Foods Plant Based diet with intermittent fasting is the secret to helping fat vegans get healthy. It’s helping me so far.

  48. As a person who has studied calorie restriction on human longevity I have found that the hard part is all of the food prep and eating so much more in bulk than normal. You see the calorie restriction diets done properly are based on nutrient dense low calorie foods. It takes me too long to do all of the prep of the multitude of produce then sit and eat that much bulk. You literally eat more on a calorie restriction diet.

    1. You seem to be misunderstanding what a calorie restricted diet is. It has nothing to do with eating large portions, just with restricting the caloric amount you eat for each meal. The goal is to *restrict* calories to reduce the total amount of caloric intake, how you get those calories doesn’t matter (or at least there isn’t nearly as much literature on it).

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