Acute Effects of Lentil Fractions on Satiety and Glycemic Responses Before and After a Meal in Healthy Young Men

Abstract

AimsLentils are a rich source of nutrients and are high in protein, starch and dietary fiber, which promote certain health benefits, such as reducing post prandial glycemia and subsequent food intake (second meal effect). However, it remains unclear which component(s) are responsible for these effects. Therefore, the present study examined the effects of consuming lentil preparations of increased macronutrient content (fiber, starch and protein) on subjective appetite, blood glucose (BG) and insulin before and after a pizza meal, served either 30 or 120 min later, in healthy young men.MethodsTwo randomized, cross over, repeated measures experiments were conducted. Forty eight healthy males consumed iso‐volumetric (300 ml) tomato soup alone (control), or with the addition of 20 g of one of the following lentil preparations: lentil protein (75%) isolate, lentil protein (55%) concentrate, lentil starch (60%) or lentil fiber (55%). Treatment consumption was followed by a fixed‐energy pizza meal (12 kcal/kg body weight), served at either 30 minutes (exp‐1) or 120 minutes (exp‐2) later.ResultsIn exp‐1, with the exception of the increase in pre‐meal BG after the lentil starch preparation (p<0.0001), there was no effect of treatment composition. The lentil protein isolate and concentrate, but not lentil starch or lentil fiber, treatments lowered post‐meal glycemia compared to the control (P<0.0001) without increasing blood insulin concentrations. No effects were seen on pre‐meal measures of satiety; however, in addition to post‐meal BG subjective appetite was also lower (P<0.05) after consumption of both lentil protein isolate and concentrate compared to the control. In contrast to exp‐1, lentil starch resulted in lower pre‐ and post‐meal subjective appetite compared to the control in exp‐2 (P<0.05); however, consumption of lentil starch also led to higher BG values. The post‐meal effects of the lentil protein preparations on lowering blood glucose were greater after the 120 min than 30 min meal.ConclusionLentil protein is the macronutrient that contributes most to the low glycemic properties of lentils. Additions of these, or similar preparations, to high glycemic foods may aid in post‐prandial glucose control.Support or Funding InformationThis study was supported by Agriculture and Agri‐Food Canada (AAFC) and Saskatchewan Pulse Growers (SPG), Canada, Reference 497290