While obesity affects 17% of adults in France, this complex pathology remains poorly understood. Many prejudices are still associated with it today. To see more clearly, we unravel together the true from the false.
False. It is not that simple. Poor diet and a sedentary lifestyle play a role, as they cause an imbalance between energy intake and energy expenditure. But other factors come into play, such as a genetic predisposition. "An individual is two to eight times more likely to be obese if family members are obese" , notes the National Institute of Health and Medical Research (Inserm). The environment also plays a role. Lack of sleep, irregular meals or night work disrupt the biological clock that regulates the body, which increases the risk of overweight. "Stress, certain medications, viruses, the composition of the intestinal microbiota, exposure to pollutants are also likely to be incriminating factors", adds Inserm. Finally, prenatal causes have been identified:maternal smoking, diabetes or maternal overweight, excessive weight gain during pregnancy, fetal growth deficit or excess, unfavorable socio-economic background.
True. Obesity has been recognized as a chronic, progressive and multi-factorial disease by the World Health Organization (WHO) since 1997. It is defined as "excessive accumulation of body fat that poses a risk to health" and is a risk factor for diabetes, cardiovascular disorders and cancer, among others. In France, however, it is not on the list of long-term conditions (ALD).
False. We usually use the body mass index (BMI), which is the person's weight (in kilograms) divided by the square of their height (in meters). When the result is equal to or greater than 30, the adult is considered obese. In children, the BMI must be compared to the reference median of each age group to determine it. However, this indicator has a limit:body composition and the distribution of fatty tissue can vary from one individual to another. Top athletes, for example, can have a high BMI without having excess body fat. To complete the diagnosis, it is possible to measure your waist circumference. It is estimated that there is abdominal obesity when it is greater than 100 cm in men and 88 cm in women.
False. It is even the opposite, diets strongly contribute to the evolution of obesity. They cause a disruption of the metabolism and promote the yo-yo effect, that is to say a rapid weight loss followed by an equally rapid or even greater recovery. This phenomenon is explained by the fact that the body is programmed to defend itself against weight loss. After a strict diet, hormones change to cause more hunger and less satiety, leading to increased food intake.
True. According to an Odoxa survey carried out for the League against obesity in 2020, 67% of French people believe that losing weight is first and foremost a question of will. But obesity is indeed a multifactorial disease that requires appropriate management. If eating a balanced diet and having physical activity are excellent for your health, this is not enough to prevent or treat it.