chubby

Example:He was visibly different from his chubby brother, being much skinnier and holding a more angular frame.

Definition:very thin in a way that is unattractive or unhealthy, having little meat on the bones

Example:The slender model glided gracefully down the runway, a stark contrast to the chubby children playing behind her.

Definition:having a small round outline, typically used to describe a slender or thin person

Example:After weeks of rigorous training, the athlete was lean and fit, far from the chubby little boy he once was.

Definition:in good condition, having a muscular, well-defined shape and relatively little body fat