There are people that cannot accept that there are those lucky bastards who can eat lots and exercise little and not put on weight, they infer that these are just naturally virtuous as it goes against their narrative that anyone overweight is due to greed and laziness.
Personally think that there is a spectrum of this from naturally slim to those who struggle to even maintain without a lot of hard work etc and that outside of eating habits and factors that impact those (eg mh, sociological, environmental)
there are chemical, hormonal, genetic and physiological factors that come in to play in varying degrees for each individual.
At least it is truthful Imo.