Effects of two consecutive mixed meals high in palmitic acid or stearic acid on 8-h postprandial lipemia and glycemia in healthy-weight and overweight men and postmenopausal women: a randomized controlled trial

Abstract

Abstract Purpose Palmitic and stearic acids have different effects on fasting serum lipoproteins. However, the effects on postprandial lipemia and glycemia are less clear. Also, the effects of a second meal may differ from those of the first meal. Therefore, we studied the effects of two consecutive mixed meals high in palmitic acid- or stearic acid-rich fat blends on postprandial lipemia and glycemia. Methods In a randomized, crossover study, 32 participants followed 4-week diets rich in palmitic or stearic acids, At the end of each dietary period, participants consumed two consecutive meals each containing ± 50 g of the corresponding fat blend. Results Postprandial concentrations of triacylglycerol (diet-effect: − 0.18 mmol/L; p = 0.001) and apolipoprotein B48 (diet-effect: − 0.68 mg/L; p = 0.002) were lower after stearic-acid than after palmitic-acid intake. Consequently, total (iAUC0–8 h) and first meal (iAUC0–4 h) responses were lower after stearic-acid intake (p ≤ 0.01). Second meal responses (iAUC4–8 h) were not different. Postprandial changes between the diets in non-esterified fatty acids (NEFA) and C-peptide differed significantly over time (p < 0.001 and p = 0.020 for diet*time effects, respectively), while those for glucose and insulin did not. The dAUC0–8 h, dAUC0–4 h, and dAUC4–8 h for NEFA were larger after stearic-acid intake (p ≤ 0.05). No differences were observed in the iAUCs of C-peptide, glucose, and insulin. However, second meal responses for glucose and insulin (iAUC4–8 h) tended to be lower after stearic-acid intake (p < 0.10). Conclusion Consumption of the stearic acid-rich meals lowered postprandial lipemia as compared with palmitic acid. After the second stearic acid-rich meal, concentrations of C-peptide peaked earlier and those of NEFA decreased more. Clinical trial registry This trial was registered at clinicaltrials.gov as NCT02835651 on July 18, 2016.