The science of calorie restriction just got a lot more complicated: Monkeys fed experimental low-calorie diets didn?t live any longer than their high-calorie brethren, a result that conflicts with a 2009 report of long-lived, extra-low-calorie monkeys. That had been the first demonstration of extended lifespans in primates, not just lab rodents, and raised hopes of the diet being a dinner-plate fountain of youth.
