Acute differential effects of milk-derived dietary proteins on postprandial lipaemia in obese non-diabetic subjects

Abstract

Postprandial lipaemia is an established risk factor for atherosclerosis. To investigate the acute effect of four milk-derived dietary proteins (alpha-lactalbumin, whey isolate, caseinoglycomacropeptide and whey hydrolysate) on postprandial lipaemia, we have conducted a randomized, acute, single-blinded clinical intervention study with crossover design. A total of 11 obese non-diabetic subjects (age: 44-74, BMI: 30-41.4 kg m(-2)) were included. On 4 different days the subjects ingested a high-fat meal with the following energy distribution: 66% energy from fat (100 g of butter), 15% of energy from carbohydrate (90 g of white wheat bread) and 19% of energy from protein (45 g of pure protein). Our primary variable was plasma triglyceride measured in the 8-h postprandial period. Secondarily, retinyl palmitate, non-esterified free fatty acids, glucose, insulin, glucagon, GLP-1 and GIP, active and total grehlin and cholecystokinin were measured. We observed no statistically significant (P=0.8) differences between meals on our primary variable that is, triglycerides. Whey hydrolysate was associated with a significantly (P=0.02) smaller postprandial suppression of non-esterified free fatty acids compared with the other dietary proteins. We did not observe significant differences in postprandial lipaemia to the four milk-derived dietary proteins. Whey hydrolysate caused less postprandial suppression of free fatty acids.