Since the early 1960s, Weight Watchers has been a kind of guru for people struggling with weight problems. The Weight Watchers program got its start when a few friends began meeting weekly to discuss how to best lose weight.

Jenny Craig: The PremiseThe Jenny Craig program was founded more than 15 years ago by a woman who was struggling with her own weight. At the time, the program was unique because it offered frozen or shelf-stable prepared meals to help with portion management and calorie-intake control.

The South Beach Diet is based on the Glycemic Index, which ranks foods according to their glycemic load. The South Beach diet focuses on a healthy balance between carbs and fats - good carbs and fats. Highly processed foods like baked goods, sweets, and soft drinks will be off-limits.