The study I would like to see is giving obese people unlimited access to only natural foods for 3 months. They could add salt and spices, but no oil and definitely no sugar. The diet would be lean(ish) meats, fruits, vegetables and legumes (unsure if allowing nuts is a good idea as they’re extremely calorie dense, but technically they should be allowed under this definition).
I would be surprised if this didn’t work. Under this model I view hyperpalatble foods as equivalent to an addictive drug for obese people. Just as if you have a poor phenotype for alcoholism, you should avoid alcohol altogether, if you have a poor phenotype for the overconsumption of hyperpalatable foods, and a poor phenotype for the conversion of those extra calories into fat, you should avoid hyperpalatble foods.
Have you ever seen or even heard of a person who is obese who doesn’t eat hyperpalatable foods? (That is, they only eat naturally tasting, unprocessed, “healthy” foods).
This seems like the occam’s razor expanation to me. Some of our new flavour/texture combinations are so rewarding that they easily overcome the natural stop signals, leading to excess caloric consumption in most (to a variable degree), which leads to weight gain in some.
A study which gave its participants a 1000cal/day dietary surplus found while some participants gained 14kg of fat over the course of the study (I think it was for 3 months), others gained as little as 4kg. As one would expect, there is genetic variance in one’s vulnerability to the effects of a harmful caloric surplus, and there is probably also genetic variance in one’s susceptability to hyperpalatable foods.