Abstract
INTRODUCTION: To date, there has been no study investigating how meal-timing impacts glucose and insulin resistance among Latino youth at high risk of type 2 diabetes. A proof-of-concept study was conducted to assess metabolic response to a test-meal consumed in the morning, afternoon, and evening among 15 Latino adolescents with obesity using a within-participant design. METHODS: Youth, 13-19 years of age, with obesity, consumed the same test-meal after a 16 h fast at three different times on separate days. Immediately after consumption of the test meal, a mixed meal tolerance test (MMTT) was performed. The co-primary outcomes were the area under the curve (AUC) for glucose, insulin, and C-peptide, and insulinogenic index (IGI). RESULTS: Twenty-two youth consented to participate for a 24% recruitment rate (78% female, 100% Latino, mean age 16.5 ± 1.3 years, 70% publicly insured). There was a significantly greater rise in glucose and c-peptide levels following at 4:00 p.m. compared to 8:00 a.m. (glucose: p = 0.006; C-peptide: p < 0.0001) with no significant association found between insulin levels and timing of meal consumption. Pairwise comparisons showed a greater rise in AUC glucose and C-peptide levels at 4:00 p.m. compared to 8:00 a.m. (glucose p = 0.003; C-peptide p < 0.001) with no significant association found between insulin AUC and timing of meal consumption (p = 0.09). There was a greater reduction in IGI at 4:00 p.m. compared to 8:00 a.m. (p = 0.027). CONCLUSION: Similar to findings in adults at risk for diabetes, Latino youth with obesity show greater insulin resistance in response to a meal consumed in the afternoon and evening compared to early morning food consumption.