Obesity causes male infertility through multiple mechanisms including hormonal disruption (low testosterone/high estrogen), increased scrotal temperature, and oxidative stress from adipokines.

Studies show that obesity contributes to infertility by reducing semen quality, changing sperm proteomes, contributing to erectile dysfunction, and inducing other physical problems related to obesity. Mechanisms for explaining the effect of obesity on male infertility include abnormal reproductive hormone levels, an increased release of adipose-derived hormones and adipokines associated with obesity, and other physical problems including sleep apnea and increased scrotal temperatures.