Episode Details

A new study of Intermittent Fasting found little benefit. Have the benefits of Intermittent Fasting been hyped beyond the science? An objective look at the caveats of the study and Intermittent Fasting in general.

A new study on intermittent fasting was written up in the NEW York times.
Half the subjects ate 3 meals with no time restriction, half were on intermittent fasting and ate in a 8h window. This is a common intermittent fasting protocol, 16/8 (eat for 8h, fast for 16). It’s also called time restricted eating

There was no significant weight loss on intermittent fasting. People on intermittent fasting lost less than 1kg. This was surprising, previous studies have shown weight loss on 16/8 intermittent fasting. Also, that weight they lost seems it was mostly lean mass, not fat. Cholesterol, glucose weren’t improved on intermittent fasting either, they track with weight loss.

Does this mean intermittent fasting doesn’t work? Some people lost quite a bit of weight and others didn’t. some even gained weight. People were instructed to eat in the 8h window and were left to decide everything else.

Most people try intermittent fasting but aren’t too strict so this is a good reflection.

They told them when but not what to eat. They didn’t measure calorie intake. No difference in calories could mean no weight loss but some studies have shown weight loss on intermittent fasting even in isocaloric conditions.

Weight loss study that doesn’t measure calories eaten? but intermittent fasting is pitched as simple, eat within a window, forget the calories and the carbs and lose weight.

intermittent fasting researcher: “there are no limitations during the eating window. There is no carb or calorie counting.”

So there’s this idea that as long as you eat in the 8h window you lose weight and this study says things aren’t that simple.

People are being told fasting detoxes you, it lets your gut rest, but the evidence indicates it's not about the fasting. It's often calorie balance or chronobiology (what time u eat), not fasting per se. We covered all of this in detail in the time restricted eating video.

People are being told autophagy will do wonders, based on extrapolations from mice. Intermittent fasting works in some contexts.

Refine the msg: eat within this time window, it makes it easier to control how much you eat, AND don't overeat calories, AND eat high quality foods.

If they tell people use this time window but still cut calories, it won't sell.

What can you do if you're interested in intermittent fasting?

1) intermittent fasting doesn’t necessarily mean losing extra fat. that may require calorie deficit
2) earlier time window. Frontloading meals and skipping dinner (early time restricted eating) instead of skipping breakfast. Shifting meals later can harm you metabolically. If I was going to try intermittent fasting I would go earlier.
3) the best diet for you is the 1 you can stick with. If intermittent fasting works for and you're losing extra fat, great
4) Losing weight vs losing fat. avoid overfocus on the scale and the numbers, loss of lean mass. it’s normal to lose some muscle during weight loss, you minimize that loss through resistance training and adequate protein.
5) losing extra fat is good but to lose weight and harm one's health beats the purpose. Whatever fat loss approach you choose, eat high quality foods
6) Beware the hype

more on intermittent fasting: full video on intermittent fasting and one focusing on time restricted eating.

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