Yep, I think something like this is the correct response, though I would prefer to see vegetables that have super-desirable test profiles that trick the body into thinking its getting the high calorie foods it's evolved to crave rather than drugs that alter the humans to want to eat less in general.
Humans are driven by biology, and psychology is only a thin abstraction on top of that. The amount of self-discipline any single individual can deploy is very limited. If that discipline threshold gets used up on other things, it's not going to be available for food and diet.
Consider on top of this that most of us have been socialized and trained for decades to prefer unhealthy options, and the already-steep incline of resisting the body's physically preferred options becomes treacherous.
Most fat people aren't fat becomes they're snarfing down platters that are meant to feed six in every sitting. They're fat because the foods they eat provide low nutrition and high calories, and candy bars aren't the only food with such a profile. Most packaged foods that you can buy at a regular, non-niche grocer are that way, even the ones that are touted as healthy. Food companies do this because they know people like foods with more calories more than they like foods with fewer calories, and they want you to buy their foods more often.
Technology got us into this mess by creating an easily-accessible supply of hyper-caloric foods, an amount of plenty that our bodies, built for scarcity, are not at all equipped to handle. Technology should be employed to fix it. Whether it's human-side or food-side, something needs to be developed that can blackhole the excess calories with no noticeable impact on the eating experience, either in taste or chemical reward.
The other alternative is to revert to a food supply where artificial contrivances such as candy and foods injected with sugars and other unnatural taste-improving formulations are very rare. This is not possible while we live in a society of abundance. It will only be possible if there is famine, hardship, war, etc. So it's not a good option.
"Just try harder" is never going to be a real answer to this problem, and the stats clearly bear that out. People hate being fat. They spend billions of dollars every year desperately trying to find someone who can fix it for them. We should try to address that in a reasonable way.