RESUMO
BACKGROUND/OBJECTIVES: The primary aim was to examine the daily glycemic response to normal-protein (NP) vs higher-protein (HP) breakfasts in overweight adolescents who habitually skip breakfast (H-BS). The secondary aim examined whether the glycemic response to these meals differed in H-BS vs habitual breakfast consumers (H-BC). SUBJECTS/METHODS: Thirty-five girls (age: 19 ± 1 year; body mass index: 28.4 ± 0.7 kg/m(2)) participated in the semi-randomized crossover-design study. The participants were grouped according to habitual breakfast frequency. H-BS (n = 20) continued to skip breakfast (BS) or consumed a NP (12 g protein) or HP (32 g protein) breakfast for 3 days, whereas the H-BC (n = 15) completed the NP and HP breakfast conditions for 3 days. On day 4 of each pattern, an 8 h testing day was completed. The respective breakfast and a standard lunch meal were provided, and plasma was collected to assess morning, afternoon, and total glucose and insulin area under the curves (AUC). RESULTS: In H-BS, the addition of a HP breakfast increased total glucose AUC vs BS (P < 0.05), whereas NP breakfast increased total insulin AUC vs BS (P < 0.05). In H-BC, the HP breakfast reduced morning, afternoon and total glucose AUCs vs NP (all, P < 0.05). No differences in insulin were detected. When comparing the HP-NP differential glycemic responses between groups, H-BS experienced greater afternoon and total glucose AUCs following HP vs NP breakfasts (both, P<0.05). No differences in insulin responses were observed between groups. CONCLUSIONS: Novel differences in the glucose response to HP vs NP breakfasts were observed and were influenced by the frequency of habitual breakfast consumption in overweight adolescents.
