Low-carbohydrate diets are supposed to decrease calorie intake without reducing satiation. They've been around for 50 years. They may work for individual people, but they do not work at scale as a public health measure.
Why is this concept so difficult to get across? There are _constant_ advertisements in every medium for weight loss programs of every sort. We've already explored the entire parameter space of dieting. Tweaking the food mix and saying, "No. This time we have the perfect mix to keep you health and full!" isn't science. It's quackery that belongs on the cover of Cosmo.
You know what works in reality?
* Amphetamines
* Nicotine
* 2,4-Dinitrophenol
* Gastric surgery of various sorts
* Cancer
Of course none of these things is an effective public health measure. (Although there's some evidence that e-cigarettes aren't quite as carcinogenic as regular cigarettes, but might still deliver all of nicotine's benefits.)
You know what might actually work?
* Pigovian taxes on high glycemic index food and drink
* A ban on food advertisement
* Portion size regulation
* Weight-based airfare
But these are all unpopular, because they contravene the pretty little dogma that we all have enough willpower within ourselves to accomplish our goals. Sometimes we need an external kick in the ass.
It's time we stop pretending that yelling at people about diet and exercise is going to make a bit of difference. We might as well yell at the sea and tell it to stop rising.