Mutual interactions between food macronutrients and digestive enzymes controls rate of enzymic digestion

Background/Aims: This study aimed to investigate if lipid droplet size manipulation via emulsification modulates blood glucose, insulin, triglycerides (TG), and appetite after a meal.Methods: This was a randomised, crossover acute feeding study that consisted of three test meals: 1) bread + olive oil-water beverage (control), 2) bread + finely emulsified beverage (FE, droplet size diameter ~0.8 mm), 3) bread + coarsely emulsified beverage (CE, diameter ~10.2mm).Fifteen healthy adult males completed the study (mean ± SD age 26 ± 6 years, BMI ¼ 22.2 ± 1.2 kg/m).Participants consumed a standardised lead-in dinner, attended test sessions after 10 h overnight fast, and a blood catheter was inserted.Fasting capillary glucose (HemoCue), gastric antral areas (ultrasonography), insulin and TG (plasma), and appetite (VAS) were assessed before test meal, at every 15mins for 60 mins, and then every 30 mins for 180 mins after test meals (240 mins total).Results: All variables, except for appetite ratings, changed significantly over 240 mins (interaction effects, p ¼ 0.002).Gastric antral area was significantly higher (delayed gastric emptying) after FE only.The iAUC of glucose and insulin did not differ between all test meals, but the peaks of these indices were delayed in FE and CE (90 mins) than control (30 mins).Postprandial TG excursions followed the following order FE > CE > control, but the iAUC was significantly higher in FE only.All appetitive measures did not differ significantly between all test meals.Conclusions: Reducing lipid particle size via emulsification reduced gastric emptying rate and increased TG in the blood more rapidly.