It has become more of a Forgotten Trope over time as most societies have themselves become more affluent and have access to more and healthier varieties of food.
This trope was more common centuries ago, when having some extra body fat meant people were seen as healthier (as opposed to typically malnourished masses), and was also a sign of affluence. A Big Beautiful Man is noticeably chubby, and perhaps even obese, and yet considered genuinely beautiful and voluptuous for it.
