system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some people gain weight in specific places (i.e. bottom heavy or primarily in the stomach) as opposed to proportionally all over the body?
gpt
A lot of it is genetic, but generally the biggest difference is hormones.  Estrogen causes fat storage primarily below the waist, testosterone causes fat storage in the abdomen.  This explains "beer bellies" being more prevalent in men, etc.