Quick Summary: Restraint theory suggests that restrictive diets lead to failure and in some cases actually increase weight gain. The theory was developed after research was showing that people on restrictive (don’t eat any of these ‘bad’ foods diets) had almost an 80% rate of failure and people were often gaining back more weight than they had when they started the diet. This post will look at how restraint theory can explain some of the failures of weight loss programs and will finish with a more reasonable solution for people trying to lose weight.