Why do i gain the majority of my weight in my stomach?

Genetics: This is a complex question. No doubt genetics plays a major role in this. Your sex is a variable (men tend to gain around the center, women hips/thighs). Other variables include the amount of carbohydrates in your diet, alcohol/sugar intake, and exercise regularity.

Abdominal fat: Agree with Dr. Cunnar. We each have different genetic dispositions which includes body type.