From a health standpoint, many things. It drastically increases your risk of heart disease, diabetes, and cancer. It curtails your mobility and flexibility and your athletic performance. It will keep you from reaching your full potential physically. It puts a lot of strain on your heart, your lungs, your joints. It will likely shorten your life if it continues unabated. If you're a woman, it endangers your fertility and makes your pregnancies and childbirth higher risk (did you know that, for example, uterine prolapse is more common in morbidly obese women than in healthy-weight ones? google that if you dare...). If you're a man, it can decrease your testosterone levels and increase your estrogens, effectively turning you into a softer, weaker man than you'd be if you were fit. There are no benefits to your health whatsoever. Food is delicious but people are slowly killing themselves with it, and it's a serious problem. We only get one body and we only get one life! Wasting both on gluttony is a tragedy. From a social standpoint, it makes finding a mate harder. Whether we like to admit it or not, we are hardwired to seek out attractive mates - and attractive, from an evolutionary biology standpoint,generally means fit and healthy. It's observable all over the animal kingdom too...animals that are weaker or injured or deformed generally don't have much luck finding mates, while the ones that are big and strong and healthy do. While some folks, like yourself, will still be attracted to fat people, the majority are not.