Reduction in Risk Factors for Type 2 Diabetes Mellitus in Response to a Low-Sugar, High-Fiber Dietary Intervention in Overweight Latino Adolescents

Objective: To examine if reductions in added sugar intake or increases in fiber intake in response to a 16-week intervention were related to improvements in metabolic outcomes related to type 2 diabetes mellitus risk. Design: Secondary analysis of a randomized control trial. Setting: Intervention classes at a lifestyle laboratory and metabolic measures at the General Clinical Research Center. Participants: Fifty-four overweight Latino adolescents ( mean [SD] age, 15.5 [1] years). Intervention: Sixteen-week study with 3 groups: control, nutrition, or nutrition plus strength training. Main Outcome Measures: Body composition by dual-energy x-ray absorptiometry; visceral adipose tissue by magnetic resonance imaging; glucose and insulin incremental area under the curve by oral glucose tolerance test; insulin sensitivity, acute insulin response, and disposition index by intravenous glucose tolerance test; and dietary intake by 3-day records. Results: Fifty-five percent of all participants decreased added sugar intake ( mean decrease, 47 g/d) and 59% increased fiber intake ( mean increase, 5 g/d), and percentages were similar in all intervention groups, including controls. Those who decreased added sugar intake had an improvement in glucose incremental area under the curve (-15% vs + 3%; P=. 049) and insulin incremental area under the curve (-33% vs -9%; P=. 02). Those who increased fiber intake had an improvement in body mass index (-2% vs +2%; P=. 01) and visceral adipose tissue (-10% vs no change; P=. 03). Conclusions: Individuals who reduced added sugar intake by the equivalent of 1 can of soda per day or increased fiber intake by the equivalent of a 1/2 cup of beans showed improvements in key risk factors for type 2 diabetes, specifically in insulin secretion and visceral fat. Improvements occurred independent of group assignment and were equally likely to occur in control group participants.