Just a thought but it would be cool if what race, class, and ability score (such as how much innate str/dex/con you have) dictates the body type of your character to a degree with an option that you can select that determines more muscle/chubb depending on your preference with the stats. Does prevent seeing a beefcake wizard but with high enough dex they would look a bit lean as you'd expect. Equal portions of Str/dex/con would be considered balanced etc.
What if I want to play a fat bald Monk that has the reflexes of a drunken monkey? I understand where the idea comes from, but it would limit the options and creativity of character creation too much.