Objective: There are inconsistent reports on the satiety value of different fatty acids. This study compared the appetitive effects of two fat sources rich in monounsaturated fatty acids (peanut oil and canola oil) with a source rich in saturated fatty acids (butter).
Research Methods and Procedures: After an overnight fast, lean participants completed a questionnaire eliciting information about hunger, fullness, desire to eat, and prospective consumption. They then consumed one of the preloads (muffins containing 40 g of each fat source or no fat) and 150 mL of water within 15 minutes. Questionnaires were completed again 30, 60, and 120 minutes after preload ingestion. Participants kept dietary records during the subsequent 24 hours.
Results: Canola and peanut oil muffins resulted in higher fullness, and butter, canola, and peanut oil muffins resulted in lower hunger ratings 30, 60, and 120 minutes after preload ingestion compared with the fat-free preload. No differences were observed among the fat-containing loads. Although energy intake 24 hours after consumption of the preloads was also comparable on days the three fat-containing loads were consumed, energy consumption after each study session was higher when the fat-free muffins were provided. However, total energy intake, including the calories provided by the preloads, was similar across treatments.
Discussion: These data do not support a differential satiety effect of fat sources rich in monounsaturated fatty acids relative to one rich in saturated fatty acids.