Obesity is a societal issue which needs to be tackled on multiple levels. Physical activity, nutrition, policies and prevention all play important roles. There are many studies that have been conducted on all of these fronts. While many common sense interventions may yield beneficial results when studied scientifically, this is not always the case. For instance well-conducted metaanalyses of physical activity programs and school-based nutrition programs yielded differing results. Physical activity interventions alone are unlikely to result in significant changes in behavior and accordingly, the BMI (1). However, school based nutrition programs were effective in reducing BMI (2). This highlights the importance of scientific research in this area and allows for the better allocation of scarce resources to treat the obesity epidemic.
Certainly, not all studies are the same. It is surprising to see that most of the research conducted is of low quality yielding results which may be useless. Despite a large meta-analysis and inclusion of many thousands of participants, the evidence level for television viewing, physical activity rates and duration, mean systolic and diastolic blood pressures, and body mass index were all deemed to be of low quality in this extensive cochrane review (1). In the Cardoso da Silveira article focusing on school based nutrition programs, 4888 articles were screened, but only 8 met the criterial for inclusion (2).
Therefore, it is of paramount importance to utilize resources which are evidence-based when implementing policies regarding obesity prevention and treatment. A great resource for what has been studied with positive results in the school setting is summarized in the “What works for Health: Policis and Programs to Improve Wisconsin’s Health” website (3).
The main issue with scientific studies is that in order to understand the effect of a single variable, all others must remain constant. However a combination approach is most likely to provide the most benefit. Designing a study to account for multiple variables is complex and makes interpretation of results difficult. Combination programs such as physical activity interventions along with nutrition interventions are likely to provide the most benefit. For instance, physical activity programs such as “Brain Breaks” and “adventures to fitness” highlighted in the “Active Schools in Wisconsin: Neenah” video if used along with interventions aimed at improving nutrition such as those highlighted in the “Chilton’s Farm to School Transformation” are likely to provide the best results (4 and 5).
1. Dobbins M, Husson H, DeCorby K, LaRocca RL. School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18. Editorial Group: Cochrane Metabolic and Endocrine Disorders Group. Published Online: 28 FEB 2013. This review is an excellent source of analyses reviewing many school-based physical activity interventions.
2. Silveira JA, Taddei JA, Guerra PH, Nobre MR. The effect of participation in school-based nutrition education interventions on body mass index: a meta-analysis of randomized controlled community trials. Prev Med. 2013 Mar;56(3–4):237–43. doi: 10.1016/j.ypmed.2013.01.011. This meta-analysis reviews the role of nutrition education in schools.