A Randomized, Controlled, Parallel Study to Assess the Effects of Soy Protein on Body Composition and General Health Parameters in Healthy Children

Abstract

It is currently unknown whether a moderate increase in daily protein intake from lean, high quality sources will affect body composition in young growing children; however, research has demonstrated a role for higher protein diets supporting healthy body composition in adults. The aim of this randomized, controlled, parallel clinical study was to assess the effects of daily consumption of soy protein foods on body composition, general health status, sleep habits, mood, and dietary intake outcomes in generally healthy children.Subjects were male and female children, 8–11 years of age, with a body mass index (BMI)‐for‐age within the 75th–95th percentile and habitual consumers of breakfast and snacks. Subjects were randomly assigned into one of two groups: 1) a Usual Protein (UP) group counseled to follow the 2010 Dietary Guidelines for Americans, in which 14% daily energy intake was from mixed protein sources, or 2) a Supplemental Protein (SP) group counseled similarly, but also provided lean protein sources to incorporate into their daily diet to reach 20% daily energy intake from protein. Both groups followed their assigned intervention for 12 weeks. The SP group incorporated study foods that were matched so each food item delivered 15 g of protein from soy. Multiple study product choices were provided, including vegetarian snack sticks, meal patties and 2 flavors of protein bars for inclusion at breakfast and a snack, leading to additional daily soy protein intake of 30g per day, as part of the counseled diet. Dual Energy X‐ray Absorptiometry (DXA) was used to determine changes in body composition from baseline to end of intervention.Subjects were well matched for baseline anthropometric characteristics (BMI‐for‐age 86.8 ± 0.9 percentile), age (9.5 ± 0.2 y), and sex (24 males, 23 females), with no observed significant differences between the two groups (n=24 in UP, n=21 in SP). Results from 3‐day diet records revealed no differences in energy intake between groups, but the SP group had significantly higher protein intake at the end of the 12 week intervention (UP 69.5±5.3g, SP 93.7±3.2g, p<.001). Quality of life assessments revealed similar responses between groups. Both groups increased fat free mass from baseline, with no significant differences observed between groups.This study demonstrates lean protein such as soy can be incorporated into a diet consistent with Dietary Guidelines to increase protein intake in children. Given that many groups are recommending increased energy from protein, this approach is an option to help aid in prevention or manage obesity.Support or Funding InformationFunding provided by DuPont Nutrition & Health