A number of medical conditions improve with weight loss in general, regardless of the cause.. They include type 2 diabetes, high blood pressure, high cholesterol, sleep apnea, heartburn, joint pain, and depression. While surgery is not considered “necessary” and is an individual’s choice, it is an option for people with BMI 35 and above if they have a medical condition related to obesity and for people with BMI 40 and above whether or not they have a related medical condition, according to according to Dr. William S. Yancy from Duke University Department of Medicine. Serious complications don’t happen often. But life-threatening side effects are possible, as is the case with any medical operation.