Effects of peanut oil. load on energy expenditure, body composition, lipid profile, and appetite in lean and overweight adults

Objective: We evaluated the effects of peanut oil intake on appetite, energy expenditure, body composition, and lipid profile in lean and overweight adults. Methods: In a parallel-arm, long-term feeding trial, lean and overweight participants received a daily peanut oil load in a milk shake equivalent to 30% of their resting energy expenditure for 8 wk. Forty-eight adults (24 lean and 24 overweight, 12 male and 12 female in each group) completed the protocol. Anthropometric indices, appetite, dietary intake, energy expenditure, and plasma lipids were monitored. Results: Energy intake increased significantly in the overweight but not in the lean participants. A statistically significant body weight gain (median 2.35 kg) was also observed among the overweight subjects, although this,corresponded to only 43% of the theoretical weight gain. Among overweight subjects, high-density lipoprotein cholesterol increased significantly and low-density lipoprotein cholesterol decreased at week 4, but neither concentration was significantly different from baseline at week 8. Similar, but less marked, changes were observed in lean subjects. Resting energy expenditure was 5% greater (P < 0.01) in the overweight group, but no significant difference was observed in the lean subjects. No marked differences of appetite were observed over time in either group or between overweight and lean participants. Conclusion: These data indicate that ingestion of peanut oil elicits a weaker compensatory dietary response among overweight compared with lean individuals. Body weight increased, albeit less than theoretically predicted. The weaker effect of whole nuts on body weight reported in previous studies suggests components other than oil may be responsible. (C) 2006 Elsevier Inc. All rights reserved.