Effects of Dairy Consumption on Body Composition and Bone Properties in Youth: A Systematic Review

Background: According to previous reviews, there is no clear evidence on the effects of dairy consumption on body composition and bone properties in pediatric populations. There is a need for further assessment of existing findings and the methodologic quality of studies before summarizing the evidence. Objective: The aim of the study was to assess the quality, methodologies, and substantive findings of randomized controlled trials (RCTs) that examined the effects of dairy consumption on body size, body composition, and bone properties in children and adolescents. Methods: After searching PubMed and Google Scholar up to December 2016, 15 RCTs were retained and included in this systematic review for further analysis. The quality of the included studies was assessed via the Jadad scale; detailed methodologic and statistical characteristics were evaluated, and the main findings were summarized. Results: The effects of dairy consumption were found to be significant for bone structure and nonsignificant for body size and composition. Eight of the 11 RCTs that assessed bone found significant effects (P < 0.05) for bone mineral content and bone mineral density (BMD), with an average 8% increase in BMD after 16 mo of dairy consumption. Conversely, significant effects (P < 0.05) were found only in 2 of the 14 RCTs that focused on body size (i.e., height and weight) and in only 1 of the 11 RCTs that focused on body composition (i.e., lean mass). Conclusions: The systematic consumption of dairy products may benefit bone structure and development, but it does not appear to affect body composition or body size in children and adolescents. On the basis of the Jadad scale, the methodologic quality of the 15 RCTs was rated as good overall. However, there were methodologic disparities and limitations that may have led to nonsignificant results, particularly for body size and composition. Future RCTs designed to address these limitations are warranted.