In a fascinating study Lawler and his colleagues review decade two of the lifetime diet restriction study of the dog. Labrador retrievers (n 48) were paired at age 6 weeks by sex and weight within each of seven litters, and assigned randomly within the pair to control-feeding (CF) or 25 % diet restriction (DR). Feeding began at age 8 weeks. The same diet was led to all dogs; only the quantity differed.
Major lifetime observations included I 8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis.
Long-term DR did not negatively affect skeletal maturation, structure or metabolism.
Among all dogs, high static fat mass and declining lean body mass predicted death, most strongly at 1 year prior. Fat mass above 25 % was associated with increasing insulin resistance, which independently predicted lifespan and chronic diseases. Metabolizable energy requirement/lean body mass most accurately explained energy metabolism due to diet restriction; diet-restricted dogs required 17 % less energy to maintain each lean kilogram.
It is hard with a domestic dog no to pamper , but farm dogs probably eat less and exercise more and live longer. There may be parallels for humans.
Dennis F. Lawler et al 2008, Diet restriction and ageing in the dog: major observations over two decades, Brit J Nutrition vol 99 pp793-805
Diet restriction: Dog: Ageing: Longevity
- Martin Eastwood