According to the WHO (World Health Organization), obesity is proven when the body mass index (BMI **) is greater than or equal to 30. But we now know that fat overload is more dangerous when is located at the level of the abdomen.

"Waist circumference is a better indicator than BMI," says Dr Boris Hansel, a nutrition endocrinologist at Bichat Hospital in Paris. This is where the problem lies: nearly half of French women have abdominal obesity (48.5%), a much higher proportion than those with general obesity.

Rich diet, sedentary lifestyle, stress: multiple causes

Some obesities are hereditary, but many other factors are involved, starting with a diet too high in calories and insufficient physical activity.

French women are indeed angry with sports : only 53% perform at least 2:30 of exercises per week according to the agency Public Health France.

"Repetitive restrictive diets also have their share of responsibility," says Anne-Sophie Joly, president of the National Collective of Obesity Associations (CNAO). By dint of yoyo, they induce a resistance of the body to the slimming and result in a consequent weight gain ".

Night work also tilts the scales in the wrong direction by desynchronizing the biological clock. An October 2017 study from the University of Hong Kong suggests that it increases the risk of obesity by 29%. Chronic stress , exposure to certain chemical pollutants and lack of sleep also favor weight gain.

Heavy consequences on health

A large excess of adipose tissue has deleterious effects on the body. In the long run, it often leads to the development of type 2 diabetes, but also increases blood pressure, enlargement of the left ventricle of the heart, and cardiac arrhythmia. As a result, the sudden death rate is 40 times higher for obese people!

Respiratory complications may also occur, as may deterioration of the liver ( fatty liver ) and kidneys. "The links between obesity and renal failure are now clearly established," says Professor Maurice Laville, president of the Kidney Foundation.

The risk of cancer is also increased, especially in the breast , ovaries, esophagus, colon, bile ducts, pancreas and endometrium.

The growing grossophobia

Judged responsible for their overweight, obese people face increasing stigma in the street and at work. In the collective unconscious, an obese person is indeed assimilated to someone devoid of will and unable to control himself.

Women are more discriminated against: an "enveloped" girl suffers from a more negative social image than a "rotten" man. As a result, she tends to lose confidence in herself, to depress and to exclude herself socially.

Solutions exist, however. Less and better eating is not enough. It is also necessary to move more, to sleep better, etc ... "To be accompanied by a professional is a guarantee of success, ensures Nathalie Négro, in charge of the nutritional center of the thermal baths of Bride-Les-Bains. The care must be multidimensional and address the emotional aspects.

And as a last resort, bariatric surgery (stomach reduction or by-pass) can be considered. The results are staggering: patients lose a lot of weight in the few months following the procedure (up to - 40 or 50 kilograms) and their health improves. But for these benefits to be sustained over the long term, medical - and sometimes psychological - monitoring is essential.

* National Institute of Health and Medical Research