Obesity prevention programs for children and youth: why are their results so modest?

Abstract

The purpose of this paper is to critically reflect upon the mixed/modest results of the primary studies related to the effectiveness of physical activity enhancement and improving nutritional intake in obesity prevention programs for children and youth. The results of a recent review of this topic that included 57 randomized controlled trials provide the basis for this discussion. Only four primary studies reported both statistically and clinically significant outcome differences between intervention and comparison groups. Although there are some similarities, there are differences among the four studies. These differences relate to program duration, frequency and intensity, targeted age of participants and level of involvement of students, the school as a community/institution and parents. Frequent methodological limitations of the studies included inadequate sample selection, lack of masking of outcome assessors, inappropriate data analysis and lack of important sub-analyses. Program design and implementation issues included lack of monitoring of program integrity and 'dose' received by participants. Theoretical basis for interventions were rarely stated and never used to explain the results. The effectiveness of parental involvement is unclear. The question of statistical versus clinical significance needs to be addressed by clinical experts. Based on this reflection, several potential future directions are outlined.

Physical activity promotion in children from northern Mexico: effectiveness of an early educational intervention program

“…Para el caso que nos ocupa, las estrategias de prevención para combatir el sobrepeso y la obesidad en niños son necesarias debido a que se considera que el periodo entre los 5 y los 8 años es crítico para el desarrollo de sobrepeso y obesidad, resaltando la importancia de implementar programas de intervención en este grupo de edad, que incluyan el aumento de la AF como medida de prevención de futuras enfermedades (Thomas, 2006).…”

Serving of free school lunch to secondary-school pupils – a pilot study with health implications

“…Different strategies, including nutritional programmes and physical activity, have been investigated in connection with the prevention of obesity among children and adolescents, but the results are meagre (20) . As the Norwegian Mean values were significantly different from those before the intervention (Wilcoxon signed-rank test): *P , 0?05, **P , 0?01, ***P , 0?001.…”

High 5 for Kids: The impact of a home visiting program on fruit and vegetable intake of parents and their preschool children

“…We are also unable to establish the clinical significance of our results. There is a lack of consensus among researchers and clinicians as to the frequency or amount of change needed to achieve both statistical and clinical significance in programs that are conducted ongoing with youth (Thomas, 2006). A final limitation to the study is the limited power to definitively assess the impact of the intervention on children within weight status subgroups.…”