Never forget that in the end it isn’t genetics or biology that ultimately determine your physical condition, it’s you.
Men in my family tend to be mesomorphic, thick in the waist. I don’t want to be. I’m not. After I dieted off weight gained while on medication I decided I wanted to keep it that way. The big change I made was retraining myself to no longer enjoy feeling stuffed. Being full is supposed to be equivalent to satiety; it feels bad to me. I don’t like feeling stuffed, so I never eat that much. I eat enough to put hunger at bay, and stop.
Visual cues are important too. Pile up your plate and you’ll feel obligated to eat it all. I eat out of chén, the standard Asian rice bowl, which is small and doesn’t suggest eating a lot.
What you eat is important to. I discovered Vietnamese food around 1994 and within two years I rarely ate anything else. I live in Vietnam now so it takes work to eat any other cuisine. Vietnamese food is very healthy but for the foundation on rice; I eat little rice, one bowl per meal but a lot of vegetables. Even fried food uses much less oil than most other cuisines, a lot of vegetables are raw and fish is a much more prominent protein source than in American food.
And two meals a day is enough. Three feels like too much food and if I eat three meals a day I start feeling bloated and I will gain weight.