EFFECT OF FENFLURAMINE ON FOOD-INTAKE, MOOD, AND PERFORMANCE OF HUMANS LIVING IN A RESIDENTIAL LABORATORY

Five male and four female normal weight research volunteers, participa ting in 13-day residential studies, received oral fenfluramine (20, 40 mg) or placebo at 09:30 and 17:00. Food intake, performance, and subj ective ratings were measured throughout the day. Carbohydrate intake w as manipulated by providing lunch meals high (males: 120 g; females: 8 0 g) or low (males: 25 g; females: 16 g) in carbohydrate on 8 days; on the remaining days subjects self-selected lunch. Total caloric intake (similar to 2800 Kcal) did not differ among the low- and high-carbohy drate, and self-selected lunch conditions when subjects received place bo, indicating caloric compensation. Total carbohydrate intake was sig nificantly less, however, when subjects consumed the low-carbohydrate lunch compared to the other lunch conditions. Fenfluramine significant ly decreased total caloric intake (similar to 500 kcal) by decreasing meal size, not number, only when subjects consumed the low-carbohydrat e lunch. Fenfluramine was only an effective anorectic drug when subjec ts consumed a lunch with fewer calories and a lower carbohydrate:prote in ratio than self-selected baseline. Also, fenfluramine improved perf ormance on a range of computer tasks and increased ratings of ''Alert, '' ''Friendly,'' and ''Talkative,'' while decreasing ratings of ''Tire d'' and ''Irritable.''