[Evidence of social support as therapy for weight loss: a systematic review].

INTRODUCTION: Social Support (SS) therapy can be an effective method of weight loss compared with conventional treatment (CT).

OBJECTIVE: To evaluate RCT's using SS therapy on weight in subjects with overweight or obesity.

METHODOLOGY: We reviewed all original articles published in MEDLINE/PubMed, SciELO, EBSCO, Google Scholar, from 2000 to August 2011, and one referred in a previous metanalisis, of RCT's of the effect of SS therapy on weight loss, with at least five months of treatment, compared with another therapy or a CT.

RESULTS: Eight articles were analyzed. It was observed heterogeneity in the design, differences in the components of the interventions, and cultural characteristics of the population. The difference between groups in weight loss in five out of seven studies, ranged from 2.3 kg (24 m) to 8.3 kg (12 m). However, the treatment in the control groups did not meet the accepted recommended guidelines. There was no allocation concealment in two studies, and no blindness in four. Most studies showed large dispersion in the results. Therefore, the quality of the evidence is low.

CONCLUSIONS: These results warrant further and better design and longer term studies to generate higher quality evidence.