Abstract
Objectives
To evaluate the effect of lifestyle change programs on weight-loss and its maintenance in obese individuals. The trial sequential analysis (TSA) was applied to determine whether the currently available evidence is sufficient.
Methods
The PubMed, EMBASE and Lilacs databases were searched for randomized clinical trials published before May of 2018. Data were pooled using an inverse-variance random-effects meta-analysis and expressed as weighted mean differences (WMD) with 95% confidence intervals (CI). Heterogeneity was quantified and explored using subgroup analyses.
Results
Eleven trials (12 publications, 1416 participants) were considered eligible to be included in this meta-analysis. Caloric restriction was effective to promote weight-loss at 12 months [WMD − 3.79 kg (95%CI − 4.78 to − 2.79), I² = 87.5%] and 24 months [WMD − 6.20 kg (95%CI − 10.81 to − 1.59), I² = 71.2%] and TSA showed convincing evidence of an effect. At 36 months, there were no differences in body weight change [−2.06 kg (95%CI − 7.00 to 2.89), I² = 0.0%] and the meta-analysis included less patients than the required information size according to TSA. Subgroup analyses suggest improved weight-loss for caloric restrictions that are greater than 501 Kcal, Dietitian as the interventionist, intensity of intervention twice a month and dropout rates of < 20%.
Conclusions
For obesity management in clinical practice, caloric restriction is effective to promote weight-loss for up to two years, preferably with a caloric deficit that is greater than 501 Kcal, if performed by registered Dietitian and if associated with a behavioral component and at least twice-monthly contact with a health team. For weight-loss maintenance greater than three years, large-scale trials are required to support these findings.
Funding Sources
This systematic review was supported by Fundo de Incentivo à Pesquisa e Eventos (FIPE) from Hospital de Clínicas de Porto Alegre. JPP was recipient of scholarships from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).