What is it about seroquel (quetiapine) that makes one gain weight? if diet stays the same will one gain weight body fat?

Gaining Weight: You will not gain weight if the diet or caloric intake remains stable. One has to consume more calories to gain weight. Many people on psychiatric medications feel more hungry and often consume more than usual calories.

Mostly not.: The medication itself does not generally cause weight gain. It causes increased appetite. There are people on the medication that do not have any weight gain.

Seroquel (quetiapine): Due to its effect on the receptors in the brain, it affect the appetite.