To maintain long term weight loss, a high protein intake and a low glycemic diet will give you better chance of success. Only approximately 17% of people can lose weight and keep it off. Combine both the nutrition with having high daily activity levels and avoid being in the 83% of people who don’t succeed.
Larsen, T.M., et al. Diets with high or low protein content and glycemic index for weight-loss maintenance. N Engl J Med. 363(22):2102-2113, 2010.