The aim of this case study was to help MH, a young adult male with Down syndrome, lose weight and improve his health. Initially he was morbidly obese, suffering from physical, mental, emotional, and health-related side effects. MH and his mother requested help from Dr. Shannon Ringenbach, and resided in Arizona for four months during the process of developing and implementing a program of diet and exercise for him. We created a plan to maximize weight loss in this short period of time. Overall, MH reduced his weight from 276 lbs. to 217 lbs. in four months, his lowest weight being 201 lbs. after he and his mother returned home to Oregon. This is a 75 lb. weight loss and body mass index (BMI) reduction of 13.7 kg/m2. Although to reach a healthy body weight MH would still need to continue his weight loss, this is a significant amount of weight, which is especially difficult for people with Down syndrome to lose. In this case study it was crucial to take into consideration the other aspects that affect weight gain and loss, such as motivation, family life, diet, and lifestyle.