This study aimed to investigate the effects of diet restriction on ageing in dogs over a period of two decades. The study analyzed data from Labrador Retrievers that had been fed either a control diet or a diet restricted by 25% of the control diet from 8 weeks of age until death. The study found that the diet-restricted dogs lived longer than the control dogs, with a median lifespan of 13 years compared to 11.2 years for the control dogs. The diet-restricted dogs also had a lower incidence of age-related diseases, such as osteoarthritis, obesity, and cancer. The study also found that the diet-restricted dogs had better cognitive function in old age than the control dogs. The findings of this study suggest that diet restriction can have significant benefits for the health and longevity of dogs, and that it may be a useful strategy for reducing the incidence of age-related diseases in dogs.