Acute effects of food products containing pulse flours or fractions, on glycemic response, insulin, appetite, and food intake in healthy young adults
Background: The glycemic benefits of consuming whole pulses alone are retained when consumed in a mixed meal, pureed, and ground into flours; however, whether pulse flours and ingredients retain the benefits of whole pulses when incorporated into extruded products is unknown. Objective: Assess the effects of replacing corn in extruded snacks and oat in extruded cereals with pulse ingredients on postprandial glycaemia, insulin, appetite, physical comfort, energy/fatigue, and food intake. Design: In two randomized, repeated-measures crossover studies, adults consumed six extruded snacks (n = 26) or cereals (n = 26). Extruded snacks were made with corn flour (control), whole yellow pea flour, split yellow pea flour, green lentil flour, chickpea flour, and pinto bean flour. Extruded cereals were made with oat flour (control), oat plus pea starch (starch), oat plus protein (protein), oat plus starch plus protein (starch+protein). Participants completed validated visual analog scale (VAS) questionnaires to measure subjective appetite, physical comfort, and energy/fatigue. Blood samples were taken throughout each session and food intake was measured at a pizza meal at 120 min. Blood and VAS measures were assessed pre-pizza (0-120 min) and post-pizza (140-200 min) meal. Results: Pinto bean and chickpea snacks led to lower (p < 0.05) pre-pizza meal blood glucose (BG) incremental area under the curve (iAUC), compared with control, whole yellow pea and green lentil snacks. Consumption of the pinto bean snack also led to lower (p<0.05) pre-pizza meal BG iAUC compared with corn control, whole yellow pea, and split yellow pea snacks. The protein, protein+fibre, and the fibre+starch+protein cereals led to lower (p<0.05) pre-pizza meal BG iAUC compared to the starch and control. The starch+protein cereal led to a lower (p<0.05) iAUC BG response compared to starch. For pre-meal overall mean insulin, fibre+protein led to a lower insulin response compared to control (p<0.05), starch+protein (p<0.05), and protein (p=0.001) cereals. Fibre+starch+protein also led to lower insulin compared to protein cereal (p<0.05). Fibre+protein resulted in lower (p<0.05) insulin iAUC compared to control and protein cereal. There were no differences in appetite, food intake, energy/fatigue, or physical comfort in response to the extruded snacks or cereals. Conclusion: The benefits of replacing corn or oat with pulse ingredients in extruded snacks or cereals on BG and insulin are dependent on pulse and fraction type utilized.