Purpose: Liquids have higher ingestion and gastric-emptying rates, resulting in rapid glycemic response. They are also less satiating than solid foods. This study examined if the addition of plant proteins alter postprandial glucose, insulin, triglycerides, glucose-dependent insulinotropic peptide (GIP), glycogen-like peptide-1 (GLP-1) and appetitive responses to a sugar-sweetened beverage.
Methods: This was a randomized, crossover acute feeding study consisting of four treatments: chocolate beverage alone (50 g carbohydrate), or added with 24 g oat, pea or rice proteins. Twenty Chinese males (mean ± SD age 26 ± 5 years; body mass index 21.5 ± 1.7 kg/m2) ingested the test drink after an overnight fast. Venous blood samples and subjective appetite ratings were collected before test beverage and at fixed intervals for 180 min. Blood biochemical data and appetite ratings were compared using repeated-measures ANOVA.
Results: Significant interaction effects were found in postprandial glucose excursions (time × protein effects, p = 0.003). Glucose iAUC was lower in pea and rice proteins, although not significantly (p > 0.385). Insulin iAUC was significantly higher in the oat (p = 0.035) and pea (p = 0.036) protein beverages. GIP and GLP-1 release in a sub-sample (n = 10) followed a comparable order as insulin release (p = 0.397 and 0.454, respectively). Significant interaction effects were found in fullness ratings (p = 0.024), and a trend of greater suppression of hunger and desire-to-eat was also documented (p = 0.088 and 0.080, respectively).
Conclusions: Plant proteins altered the glycemic and appetitive responses of Asian males to a sugar-sweetened beverage. Food-based interventions are useful in promoting glycemic control. This trial was registered with ClinicalTrials.gov as NCT02933424.
Keywords: Appetite; Blood glucose; Dietary proteins; Incretin; Insulin.