The obesity is defined as an increase of the adipose textile, which is evident for an increase of corporal weight.

The obesity for itself is a chronic illness. It is associated with an increase of the mortality and of the morbidity or predominance of multiple illnesses (diabetes, hypertension, hipercolesterolemia, gastrointestinal problems, arthritis, respiratory, dermatologic disorders and endocrinos, gallstones, cancer...).

• In most cases it owes to an imbalance of the energy balance (the ingestion overcomes to the expense).
• In certain cases it can owe to genetic alterations, illnesses endocrines (Cushing syndrome, hipotiroidismo, hipogonadismo...), medicines to itself and even neurological illnesses.
• There is studied the possibility that there exist mutations of the gene that codifies a few recipients of the hormone adrenaline called beta 3. On having diminished the activity of the above mentioned gene, a lípidos retention would take place in the greasy cells, what causes an increase of the adipose textile.

In general it is possible to affirm that the origin of the obesity is both genetic and environmental, including excess of ingestion of calories, scarce physical activity, social and economic factors and metabolic alterations and endocrines.

Diagnosis: How to know if one is obese. The method most used in Primary health care to measure the quantity of corporal fat is the index of corporal mass (IMC), which is obtained of the quotient between the weight of the subject in kilograms and his height in centimeters to the square. The values understood between 25 and 30 are considered to be an excess weight and the Superiors to 30, obesity.

To treat the obesity is difficult. The first thing that it is necessary to bear in mind is that it is a chronic illness and therefore it is not of rapid resolution.

1. To modify the food habits (to diminish the caloric ingestion).
2. To increase the physical exercise.
3. Pharmacological treatment, when it is indicated.
4. Surgery of the obesity: Only it appears in cases of morbid obesity (serious pathological obesity).

Until the fifth or seventh day the desirable target does not begin to use the adipose textile as a corporal fuel, that is to say. It is necessary to understand, therefore, that the negative energy balance (to spend more calories than they are consumed) must be supported for the long time.

A deficit of 3.500 is needed kcal to lose 0,5 Kg of adipose textile. In general, there is not recommended a loss of major 0,5-1 Kg weight for week. Also it is necessary to bear in mind that the energy needs are diminishing, approximately 12 Kcal/día less for kilo of lost weight.

It has been proved that the individuals whose corporal weight fluctuates extensively, are more inclined to suffer cardiopatías and even premature death that those who keep it relatively constant. Therefore, the most prudent attitude is to try to slim to a supported and bearable rhythm and avoid to enter alternative periods of rapid loss of weight that later recovers.