Effects of chronic peanut consumption on energy balance and hedonics

OBJECTIVE: To investigate the effects of chronic peanut consumption on energy balance and hedonics. DESIGN: Thirty-week, cross-over, intervention study. Participants were provided 2113 +/- 494 kJ/day (505 +/- 118 kcal/day) as peanuts for 8 weeks with no dietary guidance (free feeding - FF), 3 weeks with instructions to add peanuts to their customary diet (addition -ADD) and 8 weeks where peanuts replaced an equal amount of other fats in the diet (substitution - SUB). SUBJECTS: Fifteen, healthy, normal-weight (BMI of 23.3 +/- 1.8) adults, aged 33 +/- 9y. MEASUREMENTS: Dietary intake, appetitive indices, energy expenditure, body weight and hedonics. RESULTS: During FF, peanut consumption elicited a strong compensatory dietary response (ie subjects compensated for 66% of the energy provided by the nuts) and body weight gain (1.0 kg) was significantly lower than predicted (3.6 kg; P < 0.01). When customary dietary fat was replaced with the energy from peanuts, energy intake, as well as body weight, were maintained precisely. Participants were unaware that body weight was a research focus. Resting energy expenditure was increased by 11% after regular peanut consumption for 19 weeks (P<0.01). Chronic consumption of peanuts did not lead to a decline in pleasantness or hunger ratings for peanuts nor did it lead to any hedonic shift for selected snack foods with other taste qualities during any of the three treatments. CONCLUSIONS: Despite being energy dense, peanuts have a high satiety value and chronic ingestion evokes strong dietary compensation and little change in energy balance.