Size and Timing Matter: Differential Triglyceride Responses to Three Meal Conditions

Abstract

INTRODUCTIONA substantial rise in blood lipids, namely triglycerides, following a meal is associated with increased risk for cardiovascular disease, visceral adiposity, and insulin resistance. However, the vast majority of research investigating the effects of a meal on blood lipids have not utilized test meals that accurately reflect typical consumption. The purpose of this study was to compare the triglyceride response of more realistic meals, containing moderate fat and energy content, against a high‐fat meal (HFM) typically used to test triglyceride response.METHODSEight men (age: 25.8 ± 6.9 years) completed three meal trials: a HFM (17 kcal/kg body mass, 60% fat, 23% CHO); a moderate‐fat meal (MFM; 8.5 kcal/kg body mass, 30% fat, 52% CHO); and a biphasic meal (BPM), in which participants consumed the MFM at baseline and again three hours later. Venous blood samples were collected via indwelling catheter at baseline and then hourly for six hours post‐meal to assess the triglyceride response.RESULTSBaseline triglyceride values were 115.0 ± 67.5 mg/dL. Two participants presented with high mean fasting triglycerides (>150 mg/dL), while the remaining six had normal fasting triglycerides (<150 mg/dL). Peak triglycerides were significantly greater (p = 0.008) following the HFM (300.6 ± 174.6 mg/dL) compared to the MFM (164.1 ± 102.3 mg/dL), but the BPM (209.9 ± 191.9 mg/dL) was not significantly different from the HFM (p = 0.073) or the MFM (p = 0.999). The time to peak triglyceride response was significantly longer in the HFM (4.0 ± 1.2 hours; p = 0.027) and the BPM (4.5 ± 1.1 hours; p = 0.022) compared to the MFM (2.8 ± 1.2 hours), with no difference (p = 0.499) between the HFM and BPM. Total area under the curve (AUC) for triglycerides was significantly greater following the HFM (1409.3 ± 815.0 mg/dL × 6 hrs) compared to the MFM (819.1 ± 491.5 mg/dL × 6 hrs; p = 0.001) and the BPM (1003.1 ± 825.8 mg/dL × 6 hrs; p = 0.037), although the MFM and BPM were not significantly different (p = 0.952). Incremental AUC for triglycerides was also significantly greater following the HFM (679.5 ± 414.9 mg/dL × 6 hrs) versus the MFM (213.5 ± 201.7 mg/dL × 6 hrs; p = 0.004) and the BPM (300.9 ± 333.0 mg/dL × 6 hrs; p = 0.018), with no difference (p = 0.999) between the MFM and BPM.CONCLUSIONSTwo main deductions may be drawn from these findings: 1) the drastic postprandial triglyceride response following HFMs observed in previous studies may not be representative of the daily metabolic challenge of individuals eating relatively more moderate meals; and 2) when eating a HFM, smaller and/or more frequent meals appear to be better with regard to avoiding substantial postprandial triglyceride fluctuation and potential subsequent cardiovascular risk.