Systematic review of interventions in the management of overweight and obese children which include a dietary component.

Background: The prevalence of overweight and obesity in children and adolescents is increasing at an alarming rate around the world and prevention has become a key public health objective. Treatment and management of those already overweight and obese must be aligned with the best available evidence on effectiveness, if the risk of obesity-related morbidity and mortality is yet be reduced. Diet plays a pivotal role in successful treatment of obesity but to date, there is limited evidence on which to base practice.

Objectives: To identify and present the best available evidence on the optimal dietetic treatment and management of children and adolescent who are overweight or obese.

Search Strategy: Published English language literature was searched using the electronic databases CINAHL, MEDLINE, PRE-MEDLINE, DARE, COCHRANE, EMBASE, AUSTROM, Current Concepts and Dissertation Abstracts. The databases were limited to English Language from 1975 until 2003. Government reports from the UK, USA and Australian were also searched and a hand search performed for the Journal of the Dietitians Association of Australia, International Journal of Obesity and the Journal of Human Nutrition and Dietetics and the bibliographies of retrieved articles.

Selection Criteria: (i) Interventions that evaluated the effectiveness of nutrition or dietary interventions to treat or manage overweight and obesity; (ii) Children aged less than 18 years; and (iii) Participants were defined as overweight or obese by relative weight or a measure of body weight status, studies that reported body weight per se were excluded.

Data Collection And Analysis: An experienced professional librarian searched the databases, and two trained research assistants independently identified studies for retrieval and assessed each article for inclusion. The included studies were critically appraised for methodological quality by two people independently. Data were extracted from the appropriate articles and when a discrepancy arose, a third party would arbitrate.

Main Results: There were 116 articles that met the inclusion criteria. While 49 articles described randomised controlled trials, they arose from 37 separate studies. There were 67 non-randomised trials. Meta-analyses were performed on eight studies that included both a dietary intervention component and an adequate control group and on four studies that had follow-up data. There was a high degree of heterogeneity between studies and this made comparisons between studies problematic. Interventions that include diet therapy generally result in significant weight loss, at least in the short term. Many studies were poorly designed and had no or only minimal follow up. The details of the dietary intervention were often inadequately described and dietary outcomes rarely reported, making repetition of the studies difficult.

Reviewers' Conclusions: There is an urgent need for high quality studies investigating the optimal dietary approach to management of paediatric overweight and obesity. These studies require adequate follow up to ascertain if weight loss can be sustained in the long term. Details of the dietary prescription, adherence to the dietary intervention and diet-specific outcomes need to be reported in order to inform best practice.