Based on what I've read I've long believed that calorie restriction is a path to longevity and good health. Multiple animal studies have indicated that eating very little results in a longer life, and I've considered the supposed longevity benefits to be another reason to eat less (aside from the more immediate need to keep fitting into the pants I own and not be forced to buy new, bigger ones)
Devotees of this diet are influenced by books such as Beyond the 120 Year Diet: How to Double Your Vital Years and blogs such as April's CR Diary. These people eat as little as 1200 calories a day, and while it varies by body size, suffice it to say that they eat amounts that most of us would consider a severe diet to be done only temporarily before a beach vacation, but they plan to eat this little every day, forever.
So it's with some relief that I read the recent headlines about a 23-years study of rhesus monkeys which found that calorie restriction did not extend their life. The group of monkeys fed a low-cal diet (30% less calories) did experience better health in the form of later onset of age-related diseases including diabetes, arthritis, diverticulosis and cardiovascular problems, but did not live longer than the other group.
As this summary on the calorie study explains, there are still open questions about whether eating little extends life. And, of course, staying lean is generally a good idea for a list of health reasons, and (more importantly) because we tend to feel better and live easier, more active lives when we're not overweight. But, for now anyway, it doesn't appear that extreme food deprivation lengthens life. And, even if it did, would you even want those extra years if it meant a life devoid of dessert, cheese plates, wine or whatever your favorite calorie-rich indulgence is?
More on longevity: