Efficacy of very low-energy diet programs for weight loss: A systematic review with meta-analysis of intervention studies in children and adolescents with obesity.

The objective of this review was to evaluate the efficacy and safety of very low-energy diet (VLED) programs for weight loss in children and adolescents with obesity. Six electronic databases were searched identifying 24 eligible studies (16 pre-post studies, four nonrandomized trials, two randomized controlled trials [RCTs], and two chart reviews) published up to October 2018. Studies were in English, implemented a VLED (≤3360 kJF/day [≤800 kcal/day] or <50% estimated energy requirements) in 5- to 18-year-olds with obesity, and reported at least one weight-related outcome. Weight-related outcomes significantly improved postintervention in all studies. Meta-analysis of 20 studies indicated a mean 10.1 kg (95% confidence interval [CI], 8.7-11.4 kg, P < 0.001; I2  = 92.3%) weight loss following interventions lasting 3 to 20 weeks. Moderator analysis indicated greater weight loss in adolescent-only studies (10-18 years) and formulated meal replacement interventions and inpatient settings. Meta-analysis of seven studies reporting weight at follow-up (5-14.5 months from baseline) indicated 5.3 kg mean weight loss (CI, 2.5-8.0 kg, P < 0.001; I2  = 50.6%). Details of adverse events were limited. VLED programs are effective for treating children and adolescents with obesity. However, conclusions on their safety cannot be drawn from the existing literature at this time. Future studies should include long-term follow-up with ongoing support and comprehensive monitoring of all adverse events.