Define "in your control". Research finds over and over again that genetics plays a major role in BMI and that upbringing plays little or no role.

https://www.frontiersin.org/articles/10.3389/fendo.2012.0002...

One way to think about it is that certain behaviors are more controllable in the short term than in the long term. An extreme example would be breathing, which, like eating behavior, the brain subconsciously regulates by default. You can override the default and intake substantially more or less oxygen for a while. In the end, though, you will revert to to subconscious regulation and your blood oxygen level will revert to the level where your brain wants it to be.

Eating behavior seems to work in a similar way, although the timeline is much longer and the cues are more subtle.