I’ve been reading a lot of Dr. Jason Fung’s work, which is based on this theory. Anecdotally, I very much concur that weight gain is ultimately a function of something hormonal, and likely related to insulin. Running on a calorie deficit has led to little or no weight loss for me, but a diet free of processed foods and intermittent fasting has been so far successful.

That said, this theory also often attempts to challenge the calorie consumption vs energy expenditure model entirely. I think it’s a bit reductionist to rely solely on calories burned vs calories eaten (or perhaps differently stated, I think the BMR model is over broadly applied and misses how complex your body’s metabolism is), but at the same time, one aspect of a less processed diet is how, after being weaned from the processed foods, it leads one to have fewer cravings, higher energy levels, and less hunger naturally.

So the model of calorie reduction (and conversely, overeating) still seems to have some applicability, it’s just that it’s probably wrong to tackle it with “eat fewer calories” as your first and primary goal. IMO, it’s more effective to flip that around.

Eat as much whole, unprocessed food as you like without counting calories, and your hormones will adjust your appetite and energy levels such that you will inherently eat fewer calories, crave less junk food, and have more energy. The end effect of a calorie deficit is probably similar, but one is sustainable hormonally, and the other is (imo) not.

One other way of stating it - instead of viewing obesity as an effect of overeating, perhaps we could view overeating as an effect of obesity.