Effects of diets and their role in weight control.

This study examines the secondary effects of hypocaloric diets. The results show that the positive short-term effects with regards health are not maintained in the long term, as most people eventually return to their original weight. A description is given of how psychological reasons are more important than biological mechanisms when explaining this failure and stress is put on how carrying out successive hypocaloric diets can result in a subgroup of people becoming overweight or obese. Furthermore, an analysis is made of the relationship between diets, eating disorders and the "yo-yo effect", which is in turn associated with a rise in morbimortality due to a wide range of causes. As an alternative to the indiscriminate use of hypocaloric diets, a strategy based on the modification of lifestyle is suggested in order to control weight and improve health.