Dr. Rocio Arellano, MD, M.Sc., Professor at the Autonomous University of Queretaro and MD at the San Jose Hospital, Queretaro (roare2001@yahoo.com), Mexico, February 2009.
Childhood obesity increasing prevalence is a threat to the world’s health systems, and it is becoming a big concern among public health programmers. Pediatricians are facing the problem of chronic disease early in life, where dyslipidemia, hypertension and non insulin dependent diabetes mellitus are seen in most obese children. Not to mention the ill consequences in bone and joint deformation and the psychosocial implications of living as an obese child, which may remain even if not becoming an obese adult. Nevertheless, it is not clear when does disease start to develop and how the causal factors interact to initiate the morbid states mentioned above and therefore when to start prevention.
Genetic, metabolic and environmental factors all interact in an individual in order to develop obesity and the associated diseases, but the greater increase in children obesity in the last decades is not likely to be associated to genetics but to environmental factors such as a decrease in physical activity and consumption of high energy dense food. But why some children become overweight while others seem to do the same without gaining weight and balancing their weight and stature during growth? Researchers have found that even small differences in the energy balance equation, that is between energy intake or expenditure, can cause weight gain and increased adiposity in young people. Therefore, parents, pediatricians, nutritionists and health care providers should be aware that the child may not be able to compensate for this positive energy balance in the long term. Even considering that the child is growing, if it continues to have a positive energy balance of any magnitude, even of a small proportion, the child will become overweight or obese. From this point of view, it is important that even a normal weight child should remain physically active and have a well balanced diet.
Parent’s food choices and health practices highly influence children food consumption and exercise from early childhood. The so called obesogenic environment where an overweight child lives involves all the ways parents, children, and families eat and exercise on a daily basis mainly at home, but also at school, vacation periods, holidays and social events. It is difficult to separate the genetic from the environmental factors involved in obesity and its comorbidities since both are shared between parents and children, but maybe it is not a fatal destiny to be the obese child of an obese parent and become a holder of a chronic disease, if parents start doing major changes to their own lifestyles and create a family based system to remain healthy.
In the past we knew about the vicious cycle between maternal and infant malnutrition and the infectious disease risk associated. Now we understand more about the metabolic consequences of low birth weight and adult chronic disease. The malnourished child develops an insulin resistance state during the accelerated catch up growth that will increase the risk of becoming an obese adult and developing the same chronic diseases as obese children. Diabetic mothers and women with gestational diabetes give birth to macrosomic children who will be at greater risk of obesity and diabetes.
From the previous insights the answer to the question of when to start prevention of childhood obesity? Is: as early as possible and at all levels. During pregestational care, mother health and nutrition need to be addressed in order to prevent childhood obesity and chronic disease. During office consultation with pediatricians, nutritionists, and health care providers, addressing the relevance and magnitude of the childhood obesity problem and its health consequences providing sound advice on children food practices and increasing physical activity. At home, starting with parent’s lifestyle and healthy body weight to favor a healthy family lifestyle, also at schools, clinics, social events, vacations, holidays and public health politics. It is a social problem and that is how it should be solved, increasing efforts at all community levels to reverse these trends, and developing research tools to understand more on energy balance, metabolism, interaction of environmental factors and genetics involved in the development of obesity in a growing individual as well as forms of preventing and treating obesity and chronic disease in youth.