Calorie Restriction + Intermittent Fasting Are Not The Same Thing According to Dr. Will Cole
Dr. Will Cole is a functional medicine pro we turn to often for guidance on nutrition and overall health. And we’re not the only ones. Gwyneth Paltrow (who wrote the forward to Cole’s new book) recently credited Dr. Will with helping her to lose fifteen pounds of weight that had crept up on her during the pandemic.
In his new book, Intuitive Fasting, (already a best-seller!) Cole explores new perspectives on traditional ideas about fasting. Most importantly, he breaks down the idea that fasting is just about calorie restriction. Here he is with the big idea…
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The notion of not eating can trigger preexisting negative thoughts and habits, and, in some cases, following strict dietary rules. Fasting can be self-punishment disguised as a wellness practice. It’s easy to assume that fasting is just another form of restrictive dieting.
But here’s the honest truth: Real intermittent fasting isn’t about punishment, calorie restriction, or restriction at all. In fact, these things are the antithesis of the concepts presented in Intuitive Fasting.
And yet you’ll find that many people will still use “chronic calorie restriction” and “intermittent fasting” synonymously. Let me be clear: They are not. Chronic calorie restriction entails reducing your average daily caloric intake below what is normal for a long period of time. Intermittent fasting is limiting how often you eat, or not eating at all, during certain times of the day, week, or month. See the difference? The key to intermittent fasting is when you eat—not how much.
Misunderstanding #1: Because intermittent fasting leads to healthy weight loss, people conflate calorie restriction with intermittent fasting. Studies have shown that, for weight loss, fasting can be even more effective than chronically lowering your calories. For example, one study published in the reputable journal Nature showed that in 28 obese adults, fasting led to greater weight loss and fat loss than calorie restriction. 1
Misunderstanding #2: Many of us are still operating under the old logic that weight loss is all about “calories in and out,” when the reality is that weight loss is much more complicated. Your body is not a calorie calculator. It is a chemistry lab, and intermittent fasting resets the beautiful biochemistry lab otherwise known as your metabolism. Intermittent fasting causes fundamental shifts in your body’s physiology that help your body burn more fat, feel less hungry, and regain energy.
Misunderstanding #3: Chronic calorie restriction will slow down your metabolism and put your body into starvation mode, where it tries to hold on to fat. 2 One study compared the effectiveness of intermittent fasting with continuous calorie restriction and found that intermittent fasting is a great alternative for weight loss, particularly for those who find chronic calorie restriction difficult to maintain. 3
Misunderstand #4: Because fasting can cause weight loss, its health benefits must be attributed to weight loss itself. This theory has actually been studied and disproven. For example, a randomized trial consisting of 100 women—half of whom followed an intermittent fasting regimen and half of whom followed a 25 percent calorie reduction diet—showed that women in the two groups lost about the same amount of weight after six months, but the women on the fasting diet had an increase in insulin sensitivity and a larger reduction in waist circumference, which will undoubtedly make weight management easier in the long term. 4
Other studies, as cited in a large review paper published in the New England Journal of Medicine, have specifically shown that specific benefits of intermittent fasting—such as improvements in glucose regulation, blood pressure, and heart rate, and in the efficacy of endurance and abdominal fat loss—are separate from its effect on weight. 5 As the authors of the paper explain, human and animal studies have shown that the benefits of fasting are not simply the result of fasting-induced weight loss. Instead, they say intermittent fasting awakens powerful healing mechanisms that were lying dormant inside the body. Fasting enhances health and leads to weight loss in ways that are unrelated to a calorie deficit. Instead, fasting triggers shifts in metabolic and hormonal pathways that bring balance back to the body and allow it to maintain a healthy weight more easily, naturally. In short, you can get healthy so you can lose weight, instead of trying to lose weight to get healthy.
1 Byrne NM, Sainsbury A, King NA, et al. Intermittent energy restriction improves weight loss efficiency in obese men; the matador study. Int J Obes (Lond). 2018;42(2): 129-138. doi: 10.1038/ijo.2017.206.
2 Baker DB & Keramidas N. The psychology of hunger. Monitor on Psychology. 2013 Oct;44(9). http://www.apa.org/monitor/2013/10/hunger.
3 Carter S, Clifton PM, Keogh JB. The effects of intermittent compared to continuous energy restriction on glycemic control in type 2 diabetes: a pragmatic pilot trial. Diabetes Res Clin Pract. 2016; 122:106-112. doi: 10.1016/j.diabres.2016.10.010.
4 Harvie MN, Pegington M, Mattson MP, et al. The effect of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. Int J Obes (Lond). 2011;35(5):714-727. doi: 10.1038/ijo.2010.171.
5 de Cabo, R., & Mattson, M.P. Effects of intermittent fasting on health, aging, and disease. N Engl J Med. 2019;381(26): 2541-2551. https://doi.org/10.1056/nejmra1905136.
Credit line: Adapted from Intuitive Fasting. Copyright © 2021 by Will Cole. Published by goop press and Rodale Books, an imprint of Penguin Random House LLC.