Lipid droplet size and emulsification on postprandial glycemia, insulinemia and lipidemia

Previous studies have suggested that a smaller lipid droplet size results in a greater rate of lipolysis. However, acute health impacts of emulsification and small lipid droplet size are not well understood. We aimed to investigate the effect of emulsification and lipid droplet size on postprandial lipidemia, glycemia and insulinemia. Fifteen healthy Chinese males (mean ± SD, age of 26 ± 6 years and BMI of 22.2 ± 1.2 kg m^-2) participated on 3 separate occasions in a randomized order. Participants received an olive oil-water beverage and white bread as test meals. The three test beverages were as follows: (1) an olive oil-water mixture (non-emulsified, control), (2) fine olive oil-water emulsion (small lipid droplet size) and (3) coarse olive oil-water emulsion (large lipid droplet size). Glucose, insulin, triglyceride, non-esterified fatty acid (NEFA), gastric antral distention and appetite measurements were recorded for 4 hours. Glucose and insulin concentrations increased rapidly after administration of non-emulsified beverages as compared to fine and coarse emulsions with a significant difference at 30 min (95% confidence interval, P < 0.05). Fine emulsion led to a significant increase in triglyceride responses, a smaller suppression of NEFA responses and slowed gastric emptying compared to the non-emulsified beverage and coarse emulsion (iAUC, 95% confidence interval, P < 0.05). Emulsification and alteration of lipid droplet size have acute effects on glucose, insulin, triglyceride and fatty acid responses.