> unhealthy food habits
Fixing this will require systemic change, like 1) moving away from ultra-processed foods derived from cheap crops, 2) a ban on eye catching advertising for obviously unhealthy food, and 3) making well balanced and healthy food as cheap and assessable as unhealthy food.
Right now the debate is framed as an individual choice problem, but in my view it's a systemic public health problem like cigarettes. There needs to be regulation, from TV ads for Burger King to eye catching breakfast cereal boxes. If you manipulate human psychology with advertising and then hijack their biological mechanisms for sensing when they're full they don't really have a choice.
The issue is that ultra processed foods are engineered to be as addictive as possible. Fast sugars and starches with spices give fast response and provoke binge eating.
Chips are created and marketed so person will select them instead of bunch of carrots as snack. There are no sexy commercials starring raw veggies, unfortunately.
You can compare obesity with depression: both are psychological issues in most cases. It is easy to fight obesity - the person simply need to cut on calories, to get a healthy diet. However, it is really hard to do that on practice.