Age-related changes in adaptive mechanisms of macronutrient self-selection: evidence for a sexual dimorphism.
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 significantly 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.
Veyrat-Durebex
C
C
Psychophysiologie et Biochimie, EA 995, Complexe scientifique des Cezeaux, Université Blaise Pascal, Aubière, France.
Boghossian
S
S
Alliot
J
J
D000222:Adaptation, Physiological; D000375:Aging / Q000502:physiology*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002149:Energy Intake; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D008136:Longevity; D008297:Male; D005082:Physical Exertion / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D013550:Swimming / Q000502:physiology