Adolescents with intellectual and developmental disabilities (IDD) are at an increased risk of obesity, with up to 55% considered overweight and 31% obese. However, there has been minimal research on weight management strategies for adolescents with IDD. The purpose of this study was to compare the effectiveness of two weight loss diets, an enhanced Stop Light Diet (eSLD) and a conventional diet (CD), and to determine the feasibility of using tablet computers as a weight loss tool in overweight and obese adolescents with IDD. A 2-month pilot intervention was conducted. All participants were randomized to the eSLD or CD and were given a tablet computer that they used to track daily dietary intake and physical activity. Participants and parents met weekly with a registered dietitian nutritionist via video chat on the tablet computer to receive diet and physical activity feedback and education. Twenty participants (45% female, aged 14.9±2.2 years) were randomized and completed the intervention. Participants in both diets were able to lose weight, and there were no significant differences between the eSLD and CD (−3.89±2.66 kg vs −2.22±1.37 kg). Participants were able to use the tablet computer to track their dietary intake 83.4%±21.3% of possible days and to attend 80.0% of the video chat meetings. Both dietary interventions appear to promote weight loss in adolescents with IDD, and the use of tablet computers appears to be a feasible tool to deliver a weight loss intervention in adolescents with IDD.