In comparison to the average Western man, great apes – homo sapien’s close cousins – maintain a considerably low level of body fat. While the levels are less than 0.1% for male great apes and 1 to 3 % for females, they range from 15 to 20% for the average Western man and 25 to 30% for females. How can we explain this difference? Is it the result of adapting to an unpredictable environment? Brain size? Reduced reproduction cycles?
To better understand the phenomenon, journalist Jean-François Cliche from the newspaper Le Soleil interviewed researchers Simone Lemieux from the School of Nutrition and Angelo Tremblay from the Faculty of Medicine at Université Laval, both of whom are INAF members. Ms. Lemieux explained that the human body needs a higher fat level to survive. Even the fat levels of chronically underfed populations do not fall below 6 to 8%. When below 4%, organisms feed on their own cells before burning the remaining fat and the menstrual cycle stops for women who are underweight. Angela Tremblay added that when humans lose weight, they conserve their body fat and their metabolism goes into power-saving mode to reduce energy consumption.
Despite this fact, losing weight and maintaining a stable body weight are possible, but requires a long-term effort that sometimes involves lifestyle changes.
Read the article [in French only]