Ethnic differences in postprandial fatty acid trafficking and utilisation between overweight and obese White European and Black African-Caribbean men.

Black African-Caribbean (BAC) populations are at greater risk of cardiometabolic disease than White Europeans (WE), despite lower fasting triacylglycerol (TAG) concentrations. However, limited data exist regarding postprandial fatty acid metabolism in BAC populations. This study determined the ethnic differences in postprandial fatty acid metabolism between overweight and obese WE and BAC men. WE ( n =10) and BAC ( n =9) men consumed two consecutive moderate-to-high fat meals; the first labelled with U- ¹³ C palmitate. The plasma concentration and appearance of meal-derived fatty acids in very-low density lipoprotein (VLDL)-TAG, chylomicron-TAG, and NEFA were determined over 8-hours. Indirect calorimetry with ¹³ CO ₂ enrichment determined total and meal-derived fatty acid oxidation rates, and plasma b-hydroxybutyrate (3-OHB) concentration was measured to assess ketogenesis. BAC exhibited lower postprandial TAG ( P =0.006) and VLDL-TAG ( P =0.002) concentrations than WE. The appearance of meal-derived fatty acids in VLDL-TAG was lower in BAC than WE ( P =0.004). Following the second meal, BAC showed a trend for lower chylomicron-TAG concentration ( P =0.057). There were no ethnic differences in the appearance of meal-derived fatty acids in chylomicron-TAG. Cumulative fatty acid oxidation and the NEFA:3-OHB ratio were similar in WE and BAC. In conclusion, BAC exhibit lower postprandial TAG concentrations compared with WE men, driven by lower VLDL-TAG concentrations and possibly lower chylomicron-TAG in the late postprandial period. In BAC, the lower VLDL-TAG concentration was partially driven by a lower appearance of meal-derived fatty acids in VLDL-TAG. These findings suggest that postprandial fatty acid trafficking may be a less important determinant of cardiometabolic risk in BAC than WE men.