If you had asked a group of medical doctors 40 years ago whether child health would steadily improve throughout the twenty-first century, the answer would most likely have been “yes”. The vision of the link between health and environment was limited to achieving a number of well-defined goals, namely clean water, enough food, immunization, and education. One could be confident that this day would come soon since industrialized countries knew how to succeed. Time and money would solve the problem. However the reality was not entirely as predicted: a group of paediatricians met in Brussels in 1991 to react to the unexpected trend of overweight: the European Childhood Obesity Group (ECOG) was founded, almost at the same time as the International Association for the Study of Obesity (IASO) and the International Obesity Task Force (IOTF). It took several more years to convince the World Health Organization (WHO) to recognize the magnitude of the problem. Today major health actors are there to meet the needs of the 150 millions of school-aged children and about 22 million younger children which are concerned all around the world. These numbers are still steeply increasing. A first difficult task was to understand when and how one’s environment could become harmful. First of all, it became clear that humanity was not following a three-step way: under nutrition, good nutrition and eventually, obesity. Obesity is an aspect of malnutrition.
Was it a matter of threshold (too much fat, too much television, etc) or a synergistic combination? Was genetic makeup to blame? Was it a sociological matter: urbanization, women at work, family desegregation…? Was it necessary to address this issue in all children while only a minority of them were concerned?
The combination of an increasingly poor quality of manufactured diet (high in fat, sugar, salt) and soft drinks, and the decrease in consumption of fruit, vegetables and grains, is essential and explains part of the link between cancer, cardiovascular diseases, type 2 diabetes and obesity. Sedentary lifestyle decreases energy expenditure and reduces physical fitness. Exposure of children to unlimited advertising triggers at-risk behaviours. In addition to this, new facts need to be taken into consideration: pregnancy and infancy are the beginning of the high-risk period where a metabolic shift can lead to increased sensitivity to weight gain; most complications start during childhood although they remain silent until early adulthood. Childhood obesity is a cause of reduced life quality and life expectancy.