I'm of healthy size though a little soft, if only because I sit at my computer for too long and don't get out enough. I have been known to forget to eat and skip meals (because I'll be playing some video game like the pixel crack addict I am and not feel hungry until I actually realise I haven't eaten all day), and eat too many sweet/salty foods every once in a while. Usually, though, I have little compulsion to eat/not eat beyond three meals a day. (The fact that I have a very small budget might contribute to that too. The more efficiently digested food I eat, the less money I spend. However, when there's an abundance of crap, but tasty, food, you can bet I'll be munching on it too much.)
I've known some people who were fat and complained about it. They struck me as SFs or NFs. The people that I've known to be STs or NTs who were fat/overweight/pudgy, either didn't care or were mostly oblivious to it.