low-protein diet exacerbates postprandial chylomicron concentration in moderately dyslipidaemic subjects in comparison to a lean red meat protein-enriched diet

Objective: To investigate whether altering energy intake as red meat protein or carbohydrate modifies chylomicron homeostasis and postprandial lipaemia. Design: Randomized single-blind dietary intervention trial. Setting: School of Public Health, Division of Health Science, Curtin University, Perth, Western Australia. Subjects: A total of 20 moderately hypertriglyceridaemic but otherwise healthy subjects were recruited and completed the study. Intervention: Participants consumed an isocaloric weight maintenance diet low in protein (14, 53 and 30% of energy as protein, carbohydrate and fat, respectively) or high in protein (25, 35 and 30% energy as protein, carbohydrate and fat) for a period of 6 weeks. Fasting plasma lipids and postprandial lipoprotein studies (triglyceride and apolipoprotein B48) following an oral fat challenge were carried out at the start and conclusion of the dietary intervention period. Results: Consumption of the low- or high-protein diet had no significant effect on fasting plasma or postprandial lipaemia, the latter determined as the incremental area under the triglyceride curve following a fat challenge. However, subjects who consumed a low-protein diet for 6 weeks had a substantially exaggerated postprandial chylomicron response, indicated as the area under the apo B48 curve following a fat challenge. The change in postprandial chylomicron kinetics could not be explained by changes in insulin sensitivity, which appeared to be similar before and after intervention with either diet. Conclusions: Daily moderate consumption of a lean red meat protein-enriched diet attenuates postprandial chylomicronaemia in response to ingestion of a fatty meal.