Most people would be jealous of someone who can eat a lot without gaining any weight because it implies that they have a lot of self-control and are able to indulge without any consequences.
Consider the staetement "I envy people who can eat a lot and not gain weight.". Based on this statement, is "I'm feel absolutely no envy when I see people eating a lot of that delicious food and not gaining any weight" a true statement? Yes/no/unknown