It should be noted that a parallel study[1] at the National Institute for Aging (NIA) found that this was not the case. The authors of this study (UW) claim (as far as I understand) that the NIA study was flawed because both Control and Calorie Restricted (CR) monkeys were fed diets that were both restrictive, and not sufficiently different. There also seem to be some debate about the composition of the diets. The controls in the UW study were allowed to eat as they pleased (i.e. become fatties if they wanted). They claim that if both "modest" or "moderate" CR are equivalent, it would be a very important conclusion. The practical consequence, if true, would be that we wouldn't have to starve ourselves too much.
Mouse models had suggested years ago that calorie restriction could lead to ~%50 increase in lifetime. However, the problem with mouse studies is that they are pretty different, and also the mice they use are really inbred and perhaps non-ideal examples. The conclusion from the primate studies is really stacking up to be a common sense "eat in moderation, healthy, and you'll live at least a little longer, maybe a lot". Not really groundbreaking stuff, to be honest. And still not conclusive when you consider the resources that went into these studies. This also teaches us nothing about mechanisms, which would be really useful. Just my cursory assessment so far.
The publicity materials for this recent set of results do a good job of explaining why the researchers think that the NIA study is flawed. In essence the NIA control monkeys are probably on CR.
“In Wisconsin, we started with adults. We knew how much food they wanted to eat, and we based our experimental diet on a 30 percent reduction in calories from that point.” In contrast, the NIA monkeys were fed according to a standardized food intake chart designed by the National Academy of Science.
Through their own experience in monkey research, and by reference to an online database recording the weight of thousands of research monkeys, the Wisconsin researchers concluded that the NIA controls were actually on caloric restriction as well, says Colman. “At all the time points that have been published by NIA, their control monkeys weigh less than ours, and in most cases, significantly so.”
Weindruch also points to some results from the NIA that seem to contradict the “no significant result” analysis. Twenty monkeys entered the NIA study as mature adults, 10 in the test group and 10 in the control group, and five of these (four test monkeys and one control monkey) lived at least 40 years. “Heretofore, there was never a monkey that we are aware of that was reported to live beyond 40 years,” Weindruch says. “Hence, the conclusion that caloric restriction is ineffective in their study does not make sense to me and my colleagues.”
Mouse models had suggested years ago that calorie restriction could lead to ~%50 increase in lifetime. However, the problem with mouse studies is that they are pretty different, and also the mice they use are really inbred and perhaps non-ideal examples. The conclusion from the primate studies is really stacking up to be a common sense "eat in moderation, healthy, and you'll live at least a little longer, maybe a lot". Not really groundbreaking stuff, to be honest. And still not conclusive when you consider the resources that went into these studies. This also teaches us nothing about mechanisms, which would be really useful. Just my cursory assessment so far.
[1] http://www.nytimes.com/2012/08/30/science/low-calorie-diet-d...