The idea of body type or somatotype was conceptualized by Dr. W.H. Sheldon in 1940, who came up with three generalized body compositions which are endomorph, mesomorph, and ectomorph.
Endomorph: People with an endomorph body tend to have more body fat than other body types. Women who belong to this body type are usually called curvaceous while men are said to be stocky. Such a body type may gain weight very easily and quickly.
Mesomorph: Those who belong to this body type can lose and gain weight easily. They can easily and efficiently build muscle mass.
Ectomorph: Ectomorphic body types are not very muscular and have smaller bone structure. They are usually very long and thin, but they can still be skinny fat, meaning they can have low weight but high fat in the body.