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When the body does not have enough glucose for energy, it burns stored fats, resulting in a build-up of molecules called ketone bodies.
Investigators suspect that calorie reduction extends life span at least in part through increasing levels of ketone bodies.
Aging-induced change like incidence of malignancies in mice, the increases in blood glucose and insulin caused by insulin resistance, and muscular weakness.
Insulin resistance can be decreased by the metabolism of ketone bodies, a normal metabolite produced from fatty acids by liver during periods of prolonged fasting or caloric reduction.
The more calorie you reduce, the less fat your body will accumulate. Less accumulation of fat in the body makes you healthy, it prevents diabetes and other terminal diseases.