Objective: The WHO has recommended that prevention of overweight and obesity should begin early and target adults, including those with an acceptable BMI. The aim of the present paper was to systematically review published interventions with a specific stated aim to prevent weight gain.
Design: Five databases were searched to July 2008. The reference lists of review articles and obesity society meetings abstracts were hand searched. Interventions were included if the primary aim was to prevent weight gain and they included a comparison group.
Results: Ten publications were included, describing nine separate interventions in adults of various ages and target populations. All interventions incorporated diet and physical activity with behaviour change strategies. Most studies were between 1 and 3 years in duration. Five studies reported a significant difference in weight between intervention and control subjects of between 1.0 and 3.5 kg, due largely to an increase in weight in the control group. However, there was a lack of consistent, clear, psychological models and a failure to identify successful components. More intensive interventions were not always successful, nor were mail-only or clinic-based interventions. In contrast, interventions that included mixed modes of delivery with some personal contact were successful.
Conclusions: There were relatively few trials aimed at the prevention of weight gain. Existing trials varied by intensity, delivery methods, target groups and study components, and therefore provide limited opportunities for comparison of effect size. Further large, effective, evidence-based programmes are urgently needed in the general population as well as high-risk groups.