Nut consumption does not appear to lead to the expected weight gain.
A few theories have been proposed as to why nuts don't appear to contribute to weight gain, including the "pistachio principle" and the fecal excretion theory.
Note: I updated the video on August 25, 2012. I am indebted to Jeff Nelson for pointing out my mischaracterization of the 2007 Natoli & McCoy review. I've not only corrected the video, but expanded it (by 8 minutes!) to cover all of the studies published in the 5 years since. The evidence is stronger than ever that the consumption of nuts does not lead to the weight gain one would expect.
How is it possible that adding all those calories to one's diet doesn't lead to weight gain? Doesn't this violate some pesky law of physical universe (the first law of thermodynamics)? That's the subject of Monday's video-of-the-day Solving the Mystery of the Missing Calories. There definitely are foods linked to weight gain, see Does Eating Obesity Cause Obesity? and Waistline Expanding Food, for example. I give a summary of obesity in the diabetes section of my full-lengthUprooting the Leading Causes of Death as well. For more insight from the Harvard Nurses Health Study see What Women Should Eat to Live Longer, Skim Milk and Acne, Harvard's Meat and Mortality Studies, and Meat Hormones & Female Infertility.
For some more context, please check out my associated blog posts: Nuts Don’t Cause Expected Weight Gain, Plant-Based Diets for Rheumatoid Arthritis, Go Nuts for Breast Cancer Prevention, and The Best Nutrition Bar
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