Objective: Peanut consumption may improve lipid profiles without promoting weight gain. Both properties have been attributed to their high-unsaturated fat content. Mono and polyunsaturated fatty acids reportedly hold stronger satiety value than saturated fats and may help appetite control. This study investigated the effects of chronic peanut oil consumption on appetite and food choice.
Research methods and procedures: A total of 129 healthy adults from three countries (Brazil, Ghana and US) were randomly assigned to one of four treatment arms: consumption of peanut oil, olive oil or safflower oil as 30% of individual resting energy expenditure (REE) for 8 weeks or no dietary intervention. Participants received no other dietary guidance. They completed appetite questionnaires eliciting information about hunger, fullness, desire to eat, and prospective consumption during all waking hours for 1 day at weeks 2 and 6 and for 1 or 3 days at weeks 0, 4 and 8. Diet records were completed at weeks 0, 4 and 8.
Results: No differences in appetitive ratings were observed over the 8-week trial. There were no significant treatment by time interactions. Total caloric intake was significantly higher at week 8 relative to baseline (F=10.08, P<0.05). The increases for each treatment were: peanut oil=197+/-114; olive oil=237+/-121; safflower oil=274+/-90; control=75+/-71. Free-feeding intake, an index of dietary compensation, was reduced significantly at weeks 4 and 8 compared to baseline (F=9.08, P<0.00). The declines (compensation scores) were (kcals): peanut oil=-208+/-105 (46%); olive oil=-235+/-105 (50%); safflower oil=-186+/-102 (44%). There were no significant differences across countries in appetite ratings.
Discussion: A prior intervention with whole peanuts reported a dietary compensation score of 66% over 8 weeks, this compares to a 46% compensation score observed with peanut oil. Our data suggests that the lipid fraction in peanuts elicits a weak effect on satiety.