If you eat too much, the extra nutrients go into fat to be stored; it's a two way link. It effects yourself so much, that it's more the excretory system's, or the urinary system, job. The urinary system involves kidneys, urethra and the blood stream. The blood carries absorbed nutrients to the kidneys, to be absorbed. After that, it's all liquid. The digestive system deals with poop, or vice versa. Obesity makes one unable to go to the restroom correctly, but it also allows blood clots.
Hope I helped!