Is intermittent fasting popular because it’s hard??

I’ve written a fair amount about intermittent fasting in the past.  Short version: the evidence for its efficacy is not great, but it works really well for my to help maintain weight and spend a lot less time thinking about food.  In other words, I do it because it’s pretty easy for me.  So, I couldn’t let this article by Yasmin Tayag go by without comment:

Intermittent fasting has become far more than just a fad, like the Atkins and grapefruit diets before it. The diet remains popular more than a decade later: By one count, 12 percent of Americans practiced it last year. Intermittent fasting has piqued the interest of Silicon Valley broscollege kids, and older people alike, and for reasons that go beyond weight loss: The diet is used to help control blood sugar and is held up as a productivity hack because of its purported effects on cognitive performance, energy levels, and mood.

But it still isn’t clear whether intermittent fasting leads to lasting weight loss, let alone any of the other supposed benefits. What sets apart intermittent fasting from other diets is not the evidence, but its grueling nature—requiring people to forgo eating for many hours. Fasting “seems so extreme that it’s got to work,” Janet Chrzan, a nutritional anthropologist at the University of Pennsylvania and a co-author of Anxious Eaters: Why We Fall for Fad Diets, told me. Perhaps the regime persists not in spite of its difficulty, but because of it. [emphases mine]

Intermittent fasting comes in lots of different forms, which vary in their intensity. The “5:2” version popularized by Mosley involves eating normally for five days a week and consuming only about 600 calories for two. Another popular regime called “16/8” restricts eating to an eight-hour window each day. One of the most extreme is a form of alternate-day fasting that entails full abstinence every other day. Regardless of its specific flavor, intermittent fasting has some clear upsides compared with other fad diets, such as Atkins, Keto, and Whole 30. Rather than a byzantine set of instructions—eat these foods; avoid those—it comes with few rules, and sometimes just one: Don’t eat at this time. Diets can be expensive, yet intermittent fasting costs nothing and requires no special foods or supplements…

Incomplete evidence is typical for dieting fads, which tend to come and go pretty quickly in a way that intermittent fasting hasn’t. (Does anyone remember the Special K and Zone diets? Exactly.) What really sets the practice apart is how hard it is. Skipping meals can send a person into a tailspin; willfully avoiding food for hours or even days on end can feel like torture. The gnawing hunger, crankiness, and reduced concentration associated with fasting usually takes at least a month to dissipate.

Am I nuts or is this just insane hyperbole?  Having dinner before 8pm and waiting to eat again till lunch the next day is not exactly grueling?  Now the idea of going 2 full days each week without eating anything does sound really tough, so I don’t do it.  Nor do all that many other people, to my knowledge.  But simply going 16 hours without food is not some brain-numbing, tortuous experience.  Maybe I’m not particularly susceptible to low blood sugar and feeling “hangry” but I think Tayag needs to consider that she’s particularly sensitive before drawing broad generalizations about why this diet is popular.  I suspect it’s popular because a lot of people have experiences similar to me because the rules are so simple and it’s really not hard to just skip breakfast (or dinner, if that’s your preferred approach). 

About Steve Greene
Professor of Political Science at NC State http://faculty.chass.ncsu.edu/shgreene

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