Effect of stress on feeding behavior in rats: individual differences

The experiment was conducted to study individual differences in stress-indu ced changes of food intake in rats and to examine concomitant changes of no n-eating behaviors. Eating and non-eating behaviors were measured during fi ve consecutive test sessions under stressful noise (95 dB white noise, n=18 ) and control conditions (60 dB white noise, n = 18). Two thirds of the str essed rats were classified as normophagic, one third showed hypophagic resp onses. Hypophagic rats spent less time eating and more time grooming and re sting than normophagic and control rats. Hypophagic rats also showed an inc reased tendency of scanning movements during eating and an increased tenden cy to leave the food area. Their eating speed was significantly lower than that of the normophagic rats. Hypophagic rats were characterized by a heigh tened reactivity to stressors which may have counteracted the adaptation to the stressful feeding situation. Results point to a role of biological fac tors for individual differences in stress-induced changes of eating. (C) 20 01 Elsevier Science Ltd. All rights reserved.