Hunger and satiety responses to high-fat meals after a high-polyunsaturated fat diet: A randomized trial

•A diet rich in polyunsaturated fatty acids (PUFAs) increased fasting and postprandial peptide YY levels.•A diet rich in PUFAs reduced fasting, but not postprandial, ghrelin levels.•Subjective ratings of hunger and fullness were not affected by a 7-d high-PUFA diet.

ObjectivePrevious studies have shown that polyunsaturated fats (PUFAs) elicit a greater response in satiety after a single-meal challenge compared with other types of fats. The long-term effects of PUFAs on satiety, however, remain unknown. The aim of this study was to determine subjective and physiological hunger and satiety responses to high-fat (HF) meals before and after a 7-d PUFA-rich diet.MethodsTwenty-six, healthy weight (body mass index 18-24.9 kg/m2), sedentary adults were randomly assigned to either a 7-d PUFA-rich diet (n = 8 men and n = 8 women) or a 7-d control diet (n = 5 men and n = 5 women). After a 3-d lead-in diet, participants reported for the baseline visit where anthropometrics, fasting visual analog scale (VAS) measurements, and a fasting blood sample were collected. Then, two HF meals (breakfast and lunch) were consumed. Postprandial blood draws and VAS measures were collected approximately every 30 min for 4 h after each meal, for a total of 8 h.ResultsFrom pre- to post-PUFA-rich diet, there was a decrease in fasting ghrelin (P < 0.05) and an increase in fasting peptide YY (PYY; P < 0.05); however, there were no changes in fasting insulin or leptin concentrations. The postprandial response for PYY was higher after the PUFA-rich diet visit compared to baseline (P < 0.01). However, there were no differences in the postprandial response for ghrelin, insulin, leptin, or VAS measures from pre- to post-diet in either the PUFA-rich diet or control (ns).ConclusionA PUFA-rich diet consumed for 7 d favorably altered fasting and postprandial physiological markers of hunger and satiety; yet, did not alter subjective ratings of hunger or fullness.