The patient developed power saving mechanisms, because the food was not available at all times, with frequent periods of famine in the past. Each time a person starts a diet low in calories, the genetic memory kicks in and the situation is interpreted by the body as the body responds to these situations with defense actions, start saving energy and makes one of two ways:
1 Depreciation of metabolism: Every time takes less energy to survive and perform vital functions.
2 Increased efficiency in getting energy reserves and protect, ie fat accumulation and also prevents these reserves are used.
As a result of this defense mechanism the body will begin to store fat and as much exercises you perform will refuse to consume fat for energy. The fewer calories, higher response mechanisms protection. This metabolic response,
Explains why people with low calorie diets, they reach a plateau where they can not lose more weight or even gain weight despite eating small amounts. Entering this dynamically up eating little and gain fat, not the worst of this situation, the worst comes later.
During this period of calorie restriction, decreased basal metabolic rate, the body adapts to spend little power, requires little energy input to when caloric restriction decides to leave and return to a normal diet, the body receives an amount of energy that had not received, however, the body is adapted to a situation of energy saving and continue in
their efforts to spend less and build energy reserves, ie to accumulate fat with this increase in calories from the diet.
It has entered a back without return our body to be a very efficient machine famine situations, spend little and save a lot. It is for this reason that people who get weight loss through a low calorie diet, calorie restriction on leaving again gain weight and even more than in the initial state.