Each day of its life, each one must nourish and consume sufficient nutritive elements to meet its needs. The appearance of a ponderal overload reveals that, for one more or less long period, one consumed more than his needs, so that the energy reserves could be constituted in the form of body fat. Either the contributions are excessive, or the requirements in energy are too weak. Today, it should unfortunately be noted that the food requests are numerous while the occasions to be spent physically are rarer. We are in the ideal situation to eat more than necessary and thus to become gradually larger and perhaps obese. It is what indicate to us the French statistics which show that between 20 and 60 years Frenchmen takes on average 12 kg whereas the Frenchwomen gain 8 of them.

To lose weight, and especially to remain thin, this tendency should be reversed. One can follow a diet, one can increase his physical activity, one can make both at the same time. If it is wanted that the benefit last, it is necessary to agree to make a life style of it. In spite of the difficulties of such initiative, those which succeeded in overcoming obesity prove that success is with the range of all. Very restrictive diets can certainly cause a fast lose of weight at the price of great sacrifices. From their excessive nature, these diets cannot be followed very a long time. The lost weight is reinstalled as of the stop of the diet because the conditions which led to the ponderal overload are again in place. This type of diet can moreover induce nutritional imbalances and psychological disturbances. Its abandonment involves a feeling of failure which is confirmed soon by the return of the kilos. In certain cases, these excessive diets are followed by periods of loss of control where food consumption is irrepressible. It is the “yo-yo syndrome" which touches those which alternate strict diets and losses of control and undergo often considerable fluctuations of weight. It goes without saying that this syndrome is extremely prejudicial, as well to psychic balance as with nutritional balance.

A good diet is that which one can follow a long time and who can become integral part of your way of life.

It must be complete on the nutritional level, and thus varied;

it must limit the feelings of hunger;

it must be able to be carried out within the framework of the life activates of today;

it must take into account the pleasure of eating.

Except in very particular cases which require a fast diet (a surgical operation for example), a reasonable diet must allow a loss of weights of 500 gr. per week. When the ponderal objective is achieved, the same diet must be able to be followed in its principles (variety, balance, pleasure), by increasing the ration of such kind that the weight loss stops and that the desired weight can be maintained. When for the physical exercise, it is necessary to be conscious that only a vigorous and constant practice of sport can have, in the absence of diet, a slimming effect. However, it is completely recommended, for that or that which wants to lose, to increase its daily physical activity. On the one hand, the exercise will contribute to maintain the energetic expenditure (and thus, needs) on a good level in spite owing to the fact that, at certain person with the diet, the organism has tendency to reduce its expenditure thanks to various biological adaptive mechanisms. In addition, by making exercise, one preserves his muscular mass. Because, when one loses weight, the thin muscular mass tends to decrease parallel to loss of fat. To minimize this effect, it is important to make work its muscular capital for the period of the diet.

Once the diet is finished, the maintenance of a good muscular mass will prevent also the return of the kilos. Indeed, more the muscular mass is important, more the requirements in energy are large. Consequently, a person who loses weight while preserving his muscular mass will have, once achieved his ponderal goal, larger energy needs (what will enable him to eat a little more) that if it had lost by losing at the same time fat and muscular mass.