Enterostatin (ENT) has been found to inhibit food intake and selectively inhibit fat intake in rats. Both peripheral and central mechanisms have been proposed. It also has been suggested that ENT may increase thermogenesis. The present study investigated the effects of oral ENT administration on food intake, energy expenditure and body weight in subjects with a preference for a high-fat diet. In a double-blind, placebo-controlled, randomized and crossover design, nine female and three male healthy subjects (age 34 (sd 11) years, BMI 24·5 (sd 2·5) kg/m2) with a preference for a high-fat diet ingested ENT (3 × 15 mg/d) or placebo (PLA) while consuming a high-fat diet ad libitum for 4d. Eight subjects ended each intervention with a 36h stay in the respiration chamber, continuing the diet and treatment. Body-weight loss was significant (ENT 0·8 (se 0·3) kg, P<0·05; PLA 1·3 (se 0·3) kg, P<0·001), but not different between treatments. There was no difference between treatments in total energy intake (ENT 37·1 (se 2·6), PLA 35·9 (se 3·2) MJ), macronutrient composition, hunger, satiety and hedonic scores during the 4d high-fat diet. Energy expenditure (24h) (ENT 9·6 (se 0·4), PLA 9·5 (se 0·4) MJ), sleeping and resting metabolic rate, diet-induced thermogenesis, activity-induced energy expenditure and 24h RQ (ENT 0·77 (se 0·01), PLA 0·77 (se 0·01)) were similar for both treatments. We conclude that oral ENT administration did not affect food intake, energy expenditure or body weight in subjects with a preference for a high-fat diet experiencing a negative energy and fat balance.