Short-Term Standard Diet Consumption Prior to the Oral Fat Tolerance Test Modulates the Postprandial Triglyceride Response

We hypothesized that the consumption of a 3-day standard diet (SD) prior to the oral fat tolerance test (OFTT), used to evaluate postprandial lipemia, may counteract the undesirable effects of individual dietary habits on the test results. The OFTT was applied to 22 healthy adults (11 females and 11 males), after their habitual diets (HDs) and following the consumption of a 3-day SD (45–60% energy from carbohydrate, 20–35% from fat, and 10–20% from protein). Plasma triglyceride (TG) concentrations were measured during fasting and at the fourth hour of the OFTT. A 3-day SD significantly reduced fasting and fourth-hour TG concentrations and delta TG values by 10%, 12.8%, and 22.7%, respectively. Decreases were observed in fasting and fourth-hour TG and delta TG values following the 3-day SD compared to the HD in subjects with fasting TG concentrations between 89 and 180 mg/dL (p = 0.062, p = 0.018, and 0.047, respectively). As a result, the consumption of a 3-day standardized diet prior to the OFTT may be useful to eliminate the false positive or negative effects of individual dietary habits on test results and to correctly identify individuals who should be administered the OFTT.