Mechanisms of Ageing and Development 103 (1998) 223–234 Age-related changes in adaptive mechanisms of macronutrient self-selection: evidence for a sexual dimorphism Christelle Veyrat-Durebex, Stephane Boghossian, Josette Alliot * Psychophysiologie et Biochimie, EA 995, Complexe scientifique des Cezeaux, Uniersite ´ Blaise Pascal, 63 177 Aubie `re cedex, France Received 8 September 1997; received in revised form 7 January 1998; accepted 9 January 1998 Abstract The effect of aging on patterns of food intake and nutrient selection was investigated using a longitudinal study. Male (n =10) and female (n =10) Wistar–Lou rats from 4 to 28 months of age were repeatedly submitted to a macronutrient self-selection (S – S) regimen while controls were maintained under a standard chow diet (Std). An age-related shift of preferences from CHO to fat diets, and a decrease in protein intake for both males and females were evident. Nevertheless, all these modifications were more pronounced and precocious for males. Physical exercise (45 min/day of swimming, on 6 days) induced a body weight loss and an hypophagia more pronounced for males than for females. S–S regimen results revealed that hypophagia concerned exclusively fat intake and that females signifi- cantly increased protein intake during and after the exercise period. Study of longevity curves showed a decrease of the mortality in S–S submitted male rats compared to control rats. This study shows that aging induces a sex-difference in feeding patterns which undoubtedly reveals a sex-difference metabolic requirements. Moreover, these results suggest that allowing rats to select macronutrient intakes could delay the process of senescence. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Rat; Aging; Macronutrient; Longitudinal study; Exercise * Corresponding author. Tel.: +33 4 73407476; fax: +33 4 73407903. 0047-6374/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0047-6374(98)00013-X