Fasting is the practice of abstaining from food for a period of time, while caloric restriction is a dietary regimen that simply reduces caloric intake. The greatest caloric restriction is no calories at all. Fasting has been branded the “next big weight loss fad” but has a long history throughout various spiritual traditions, practiced by Moses, Jesus, Muhammed, and Buddha. Today, about one in seven American adults report using some sort of fasting as a means to control body weight.
Rather than cutting calories day in and day out, what if, instead, you just ate as much as you wanted every other day? Or for only a few hours a day? Or what if you fasted two days a week or five days a month? These are all examples of intermittent fasting regimens, which I cover in my book How Not to Diet, and they may even be the way we were built to eat. Three meals every day may be a relatively novel behavior for our species. For millennia, our ancestors often may have consumed only one large meal a day or went several days at a time without food.
Intermittent fasting is often presented as a means of stressing our bodies—in a good way—and some forms may be safe and effective (and it’s safe to say cost-effective when it comes to your grocery bills), but apparently no more so for weight loss than continuous caloric restriction. However, combining intermittent-fasting regimens, such as early or midday time-restricted feeding with a healthier diet during the feeding windows, may prove to be particularly powerful. The weight may be worth the wait.
Our fasting for weight loss infographic compares the advantages and disadvantages of different types of fasting based on the latest evidence.
The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.
Popular Videos for Fasting
Fasting Before and After Chemotherapy Put to the TestDo the benefits of short-term fasting during cancer therapy found in the lab translate into...
Fasting for Cancer: What About Cachexia?What did randomized controlled trials find as the effects of supplemental feeding on clinical outcomes?
Fasting to Reverse DiabetesBy losing 15 percent of their body weight, nearly 90 percent of those who’ve had...
Fasting to Treat DepressionCaloric restriction can boost levels of brain-derived neurotrophic factor (BDNF), considered to play a critical...
The Benefits of Fasting for HealingWhere did the idea of therapeutic fasting come from?
The World’s Largest Fasting StudyBuchinger modified fasting is put to the test.
Is Fasting Beneficial for Weight Loss?Fasting for a week or two is like the keto diet—it can actually slow body...
Is Fasting for Weight Loss Safe?The reasons why fasting longer than 24 hours, and particularly three or more days, should...
Is Alternate-Day Intermittent Fasting Safe?Eating every other day can raise your cholesterol.
Does Intermittent Fasting Increase Human Life Expectancy?Alternate-day modified fasting is put to the test for lifespan extension.
The Benefits of Early Time-Restricted EatingCalories eaten in the morning count less and are healthier than calories eaten in the...
How to Lower Blood Pressure Naturally with Lifestyle ChangesThe effect of fasting to lower blood pressure compared to medications, cutting down on alcohol,...
Fasting to Naturally Reverse High Blood PressureA whole food plant-based diet can be used to help lock in the benefits of...
All Videos for Fasting
Fasting-Mimicking Diet Before and After Chemotherapy
How might we replicate the protective effects of fasting with food?
Fasting Before and After Chemotherapy Put to the Test
Do the benefits of short-term fasting during cancer therapy found in the lab translate into the clinical setting?
Fasting Before and After Chemotherapy and Radiation
Might short-term fasting during cancer treatment minimize side effects while boosting efficacy?
Fasting for Cancer: What About Cachexia?
What did randomized controlled trials find as the effects of supplemental feeding on clinical outcomes?
How to Boost FGF21 with Diet for Longevity
Fasting and exercise can boost the longevity hormone FGF21, but what can we eat—or avoid eating—to get similar effects?
Life Extension with FGF21
What can we do to boost the longevity hormone FGF21?
Fasting to Reverse Diabetes
By losing 15 percent of their body weight, nearly 90 percent of those who’ve had type 2 diabetes for less than four years can achieve remission.
Fasting for Post-Traumatic Brain Injury Headache
What effect do fasting and a plant-based diet have on TBI and migraines?
Fasting for Irritable Bowel Syndrome
More than half of IBS sufferers appear to have a form of atypical food allergy.
How to Boost Brain BDNF Levels for Depression Treatment
Fasting and exercise can raise BDNF levels in our brain, but this can also be achieved by eating and avoiding certain foods.