Body shape
Sims can have different body shapes. Pregnancy also affects body shape.
The Sims
The Sims has different clothes for every body shape. The basic body shapes for adults are fat, fit and skinny, though custom body shapes are possible. Children have their own body shape.
The Sims 2
In The Sims 2, Sims can have three body shapes - fit, normal and fat. They cannot be fit at creation, though their fitness level and body shape flags can be manipulated with SimPE. It is affected by eating or working out.
The Sims 3
In The Sims 3, obesity and muscularity can both be varied on a continuous scale. They are affected by eating and exercise. In The Sims 3: Late Night there are new body shapes sliders: realistic muscles (for males & females), breast (females).