If you've ever described yourself as apple- or pear-shaped, you're borrowing the idea of somatotypes, first described by William H. Sheldon Jr., a physician and psychologist. Sheldon grouped people into three categories: Ectomorphs are naturally thin and long; endomorphs are round and tend to gain weight easily; and mesomorphs are sturdily built and gain and lose weight quickly.
Endomorphs tend to be lovers of food who don't deal well with restrictive diets. Nutrition therapist Annette Colby recommends that endomorphs eat four to six small meals per day with a mix of proteins and carbohydrates to maintain energy. Focus on enjoying each meal slowly, and if you decide to eat a treat, make your next meal extra healthful.
Mesomorphs tend to be high-energy, athletic individuals who get in the habit of eating a lot when they are young. As they age, mesomorphs often gain weight because they fail to adjust their eating habits for a slower metabolism. Mesomorphs should be mindful of portion sizes and save desserts and high-fat foods for the occasional treat.