Out of my sims five kids Corey was the only one that aged up to a teen with a bigger body type, he was always on the swings and playing on the jungle gyms and on the hanging bars as a child but he did love his ice-cream when he was a child and ate loads of it 😄 His merman body type is totally different from his normal body and when he works out on the weights and the treadmill his normal body doesn't get slimmer or gain muscle but his merform gets all the muscles, it's like the game chose his merform to be the one that got all the family genetics as its more or less the same as his parents body types and chose a random body for his normal form 😂