Clinical Question

Are diet, physical activity, and behavioral interventions effective in helping overweight and obese children lose weight?

Evidence-Based Answer

Interventions that include combinations of diet, physical activity, and behavior changes may reduce weight, body mass index (BMI), and BMI z-score (equivalent to BMI-for-age percentile) in overweight and obese children six to 11 years of age. These reductions are small and short term, however, and further studies are needed to determine the sustainability of these effects.¹ (Strength of Recommendation: C, based on consensus, disease-oriented evidence, usual practice, expert opinion, or case series.)

Practice Pointers

In the United States, 16% of children and adolescents two to 19 years of age are overweight (defined as age- and sex-specific BMI in the 85th to 94th percentile), whereas 17% are obese (BMI in the 95th percentile or greater).² Childhood obesity leads to adult obesity and is associated with a higher risk of respiratory, metabolic, and psychosocial conditions throughout the life span.^3–6 The purpose of this Cochrane review was to identify effective behavioral interventions to help at-risk children lose weight.¹

This updated systematic review included 70 randomized controlled trials with 8,461 participants, all of whom were six to 11 years of age. Most of the studies were conducted in high-income countries, with nearly one-half in the United States. Settings included subspecialist, primary care, and community-based interventions, and ranged from six months to three years. Thirty-two studies included children who were overweight or obese at baseline, 26 studies included only children who were obese, and five studies included only children who were overweight.

Study interventions included combinations of behavioral therapy, diet, and physical activity, and were provided or recommended by registered dietitians, therapists, or psychologists. Primary outcomes included changes in measured weight, BMI, and BMI z-score. Only a limited number of trials reported health-related quality of life or behavior change outcomes, and no trials reported all-cause mortality, morbidity, or socioeconomic effects.

Compared with no treatment or usual care, behavioral interventions reduced participants' body weight by 3.2 lb (1.45 kg; P < .00001; 95% confidence interval [CI], −1.88 to −1.02; 17 trials), BMI by 0.53 kg per m² (P < .00001; 95% CI, −0.82 to −0.24; 24 trials), and BMI z-score by 0.06 units (P = .001; 95% CI, −0.10 to −0.02; 37 trials). Effects persisted at the end of the interventions and up to six months postintervention.

The U.S. Preventive Services Task Force currently recommends that clinicians screen for obesity in children six years and older and offer comprehensive, intensive behavioral interventions to assist with weight loss (B recommendation).⁴ This Cochrane review supports those recommendations and provides limited evidence that interventions incorporating diet, physical activity, and behavior change may assist with short-term weight loss in children six to 11 years of age. Further studies are needed to determine long-term benefits and generalizability to diverse populations, as well as to inform public policy to increase access to such multicomponent interventions.