Effects of early under-nutrition on dietary self-selection and relative carbohydrate- and protein-conditioned preferences

Rats were either under-nourished from birth to 45 days and thereafter well fed, or were well-nourished throughout. Such previously under-nourished rats (PU) had a body weight deficit in adulthood of about 15% when compared with the well-fed group (C). On four training days, rats were presented with a distinctively odourized solution of carbohydrate or protein, following a 5-h period of food deprivation. On the test day, under the same food deprivation conditions as occurred during training, identical solutions distinguished only by their odour were presented simultaneously to the rats for a period of 20 min. PU rats showed a conditioned preference for the carbohydrate-paired odour. Control animals showed a small preference for the protein-paired odour. The same rats were later allowed to self-select from three macronutrients for a period of 8 days. No differences in dietary self-selection patterns were found between PU and C rats.