Snell Dwarf mice burn more fat, less sugar when at rest.
Do the modern diseases of civilization have a common cause? Is this cause a series of roaming brownouts, energy shortages throughout the body? Wear exceeds repair, and the repair that is done is shoddy.
This could show up in a number of areas, including;
1 tissue that receives relatively little blood flow.
2 tissue in higher than usual need of energy for repair. Such as the arteries, especially at main branching points.
3 tissue with very high energy needs at the best of times, such as the brain.
There is strong evidence that increased energy from fatty acids vs. glucose use during fasting increases the lifespan, this crosses a wide number of species. I see longevity as the fight against entropy. Things last longer if kept in better repair. Interventions that increase HDL and lower triglycerides in humans also raise free fatty acids, which induces physiological insulin resistance.
Which should also have the obvious effect of lessened disruption of the delivery of the energy needed for proper maintenance and repair to high-need tissues with less disruption. I see the possibility of a condition similar to a bloom in yeast, depleting blood of nutrients in a very localized hypoglycemia. Measuring blood sugar doesn't tell you what is happening in a very acute area.