[Effect of carbohydrate-enriched diet and subsequent food restriction on life prolongation in Fischer 344 male rats].

Increased proportion of carbohydrates (dextrin) in the diet has a life prolonging effect upon male Fischer 344 rats; however, the effect of this diet appears only when the rats aged from 6 weeks to 6 months are on diet, after this treatment median survival of experimental animals increases by 96 days and the 10th percentile increases on the average by 10 days (n-60). Further maintenance of animals on the same diet has minimum effect: animals being on this diet throughout the whole life exhibit a median lifespan increase by 120 days and an increase in the 10th percentile by 41 days. However, if such animals aged 6 months are transferred to a restricted (60%) food intake regimen (control diet, not enriched with carbohydrate) a further increase in median and 10th percentile lifespan prolongation can be observed reaching 328 and 396 days, respectively as compared to controls. The effects of this early feeding (from 6 weeks to 6 months) with a carbohydrate-enriched diet available ad libitum and food restricted (60% controls) regimen fed from the age of 6 months onwards are additive, the final results being identical as if the animals are kept on the 60% food restricted intake throughout the whole life.