Interventions to prevent obesity in children and adolescents: a systematic literature review.

OBJECTIVE: Preventive measures to contain the epidemic of obesity have become a major focus of attention. This report reviews the scientific evidence for medical interventions aimed at preventing obesity during childhood and adolescence.

DESIGN: A systematic literature review involving selection of primary research and other systematic reviews. Articles published until 2004 were added to an earlier (2002) review by the Swedish Council on Technology Assessment in Health Care.

METHODS: Inclusion criteria required controlled studies with follow-up of at least 12 months and results measured as body mass index, skinfold thickness or the percentage of overweight/obesity. Children could be recruited from normal or high-risk populations.

RESULTS: Combining the new data with the previous review resulted in an evaluation of 24 studies involving 25 896 children. Of these, eight reported that prevention had a statistically significant positive effect on obesity, 16 reported neutral results and none reported a negative result (sign test; P=0.0078). Adding the studies included in five other systematic reviews yielded, in total, 15 studies with positive, 24 with neutral and none with negative results. Thus, 41% of the studies, including 40% of the 33 852 children studied, showed a positive effect from prevention. These results are unlikely to be a random chance phenomenon (P=0.000061).

CONCLUSION: Evidence shows that it is possible to prevent obesity in children and adolescents through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity.