Lifestyle interventions targeting changes in body weight and composition among youth with an intellectual disability: A systematic review

• Studies mostly observed a reduction in weight, body mass index, and fat mass (in kg).
• Mixed and inconclusive findings were found for changes in percentage of fat mass and waist circumference.
• Changes in healthy lifestyle and in secondary health conditions represent an under-researched area.

Over the past three decades, the potential effects of lifestyle interventions targeting changes in body weight and composition (weight, body mass index, fat mass, waist circumference) among adults with an intellectual disability (ID) have been examined in various systematic reviews. Nevertheless, since the middle of the 1980s, the potential effects of these interventions for youth with an ID remain an open question. The purpose of this article is to review the effects of lifestyle interventions targeting changes in body weight and composition among youth with an ID. This review will focus on changes in body weight and composition, healthy lifestyle, and secondary health conditions. A systematic review of English- and French-language studies, published between 1981 and 2013, was performed on Academic Search Complete, PsycARTICLES, Medline and Scopus. The nine studies included in this review focused mainly on: a sample with a wide age range (e.g., 7–22 years); males; overweight-obese youth having a mild-to-moderate ID with Down or Prader-Willi syndrome; physical activity interventions; cohort pre- and post-test designs with/without a control group; and changes in body weight and composition. Taken together, results from these studies suggest successful changes in weight, body mass index and fat mass. However, intervention effects on healthy lifestyle and secondary health conditions are scarce and inconclusive. Given the weaknesses of the reviewed studies, the present findings should be considered preliminary and indicative of the need for future research.