Nutrition professionals (nutritionists, dieticians, doctors, researchers, agri-food engineers, paramedics, science journalists) gathered at the Annual Benjamin Delessert Days questioned BMI as a unique measure of the health risks of the patient. or under weight.
“Now it is necessary to go beyond BMI. Improving the care and fate of obese subjects by personalizing therapeutic proposals requires going further than classifying individuals according to their body mass index ”explains Dr Emmanuel Disse of the Center’s Endocrinology, Diabetes and Nutrition Department. Hospitalier Lyon.
Limits of BMI
The World Health Organization uses the body mass index (BMI, the ratio of weight to the square of height) to study the corpulence of populations at the global level.
But BMI is an indicator that has limits. The WHO thresholds do not, for example, take into account the ethnic or national characteristics of the patient (for example an Asian is obese with a BMI of 27, while a European would be “only” overweight) the sex and the distribution of fat mass.
“However, the location of fat is crucial to determine its effect on the body. Fat placed on the hips does not have the same consequences as abdominal fat or fat found around certain vital organs such as the heart, pancreas or liver. They are called ectopic fats and they are the most deleterious, ”explains Prof. Anne Dutour-Meyer, head of the endocrinology, nutrition and metabolic diseases department at the North hospital in Marseille. “A person can have a normal BMI (between 20 and 25), but an abnormally localized body fat mass and be at risk of diabetes or cardiovascular disease. “
A paradox confirmed by the figures. ” 20 to 30% of the obese population does not have metabolic complications(diabetes, high blood pressure or dyslipidemia). These patients are considered “metabolically healthy”. Conversely, some subjects have a normal BMI but severe metabolic complications: these are subjects of normal weight that one could qualify as metabolically obese ”explains Dr Emmanuel Disse.
New measures
To better describe and treat the different forms of obesity, which is a multifactorial disease, professionals should use simple complementary measurement tools such as waist circumference or waist-hip ratio, fasting blood sugar level and blood sugar level. triglycerides. “The analysis of these different elements could make it possible to better approach the cardio-metabolic risk than the simple measurement of the BMI” concludes Pr Ziegler, head of the Diabetology department at the CHU of Nancy.
