Different diets work for different people, but it may be about more than just personality type and food preferences. New research suggests that your biology may have a lot to do with having more success on some diets over others. In a study looking at individuals on low-glycemic-load diets, those who secreted more insulin naturally lost much more weight than those who secreted lower levels of insulin. But those same people who were so successful on the low-glycemic-load diet lost a lot less weight when on a low fat diet instead. But the lucky ones are the people who generally have less insulin in their systems, because they did equally well on both diets.

Although this study was obviously very limited regarding the diets it looked at compared to how many options are out there these days, it does take a little of the wind out of the sails on the "it's all your fault" ship. If you're having trouble, and you don't think willpower is an issue, have you considered that maybe you're just on the wrong diet for your biology?