Changes in food intake and food selection in rats after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on food selection wer e studied in TCDD-resistant Han/ Wistar and TCDD-sensitive Long-Evans rats and their crosses. The rats were offered a selection diet consisting of cho colate, cheese. and chow, and TCDD was given at the same time or 4 or 16 da ys later. TCDD persistently reduced the chocolate intake. When the selectio n diet was started at the time of or less than 11 h after TCDD exposure, TC DD almost completely prevented the intake of chocolate and also cheese in a ll strains already on the first day, while controls started to consume larg e amounts of both foods. This may be due to conditioned taste aversion. The effect on food selection with familiar foods seemed to reduce fat intake, while protein and carbohydrate intakes were more variable. There were no ma jor strain differences in the chocolate intake inhibition despite a 1000-fo ld sensitivity difference in TCDD lethality. (C) 2000 Elsevier Science Inc.