The Effects of Peanut Butter Overfeeding on Body Composition

Nova Southeastern University, Davie, Florida, USA

Objective: The purpose of this investigation was to assess the effects of short-term peanut butter overfeeding on body composition in active men and women. Background: There is no prior research on what happens to body composition when overfeeding on a particular food. Methods: In a single-arm open-label trial, six exercise-trained subjects (2 male, 4 female) participated in this investigation. They were instructed to consume four 16-ounce jars of Smuckersâ peanut butter in four weeks such that their total daily energy intake exceeded their previous habitual intake. Body composition and total body water was assessed via the Bod Podâ and bioelectrical impedance (Impedimedâ). Results: Subjects consumed significantly more total kcals (+268 kcals), fat (+27 grams) carbohydrate (+6 grams). There were no changes in protein consumption. Body weight (+1.1 kg), fat mass (+0.7 kg), and lean body mass increased (+0.4 kg). Total body water decreased (-0.9 liters). Conclusion: Daily overfeeding on fat (primarily from peanut butter) results in an increase in body weight. The increase in weight was due primarily to a gain in fat mass (64% of the weight gain) and secondarily from lean body mass (36% of the weight gain).