It turns out the meaningful question in nutrition is how you get people to comply to a calorically balanced diet when they are depressed and in front of a buffet of both chicken breast and cake, not which is the best one. This has as much to do with social science (and psychology and everything else) as it does biology. In fact, the metabolic part is the easy part: we basically know how that works as well as we need to fix the problem: eat fewer calories.
Now how do you convince 150 million Americans using food as an emotional outlet to stop doing that? Especially when close to 100% of the population that is not experiencing food scarcity does this to some extent, some just worse than others.
It's a lot more complicated than explaining to them that eating too much is bad and that a diet high in sugar is more likely to cause them to do that. It's like telling heroin addicts that opioids lower their life expectancy and expecting them to then stop using heroin. This problem is existential.