What if you heard that you could eat less, and live longer? Sound too good to be true? There's been a lot of buzz for the past few decades (in fact since the 1930s) about what's called "caloric restriction", and how it promotes longevity. Both Wired (July 9) and the New York Times (Friday, July 10) recently revisited this topic.

Early studies in mice, and newer studies in monkeys seem to suggest that when caloric intake is cut by about one third of what would be considered "normal" to maintain a healthy weight, that these animals live longer. Cutting calories by 30% is a big decrease, and significant weight loss occurs; the big debate is whether it's a healthy way to live.

In humans, there's a caloric restriction society, whose members adhere to this way of eating. To me, the folks look excessively thin (a BMI in the "unhealthy" range), but claim to be energized, feel great, and report excellent physical health.

This isn't about weight loss, and reducing calories to remain in a stable weight range (the kind of caloric restriction most of us deal with on a daily basis). This is cutting significant calories from your maintenance calories. For example, if you eat 1800 calories daily, to remain at a certain weight, within a healthy range, you'd voluntarily consume about 1200 calories daily, as a "calorie restrictor". This is not anorexia - although weight loss occurs in all people doing this (not a surprise!). People DO eat, and work hard at maintaining a healthy diet.

While there's no guarantee that calorie restriction promotes longevity in humans (the society members DO believe this), the newest 20-year study in monkeys suggests that this appears to be true in primates (monkeys and humans are in this class together), and not just mice. While the mechanism(s) by which this might be occurring are currently unknown, multiple studies are ongoing to continue to explore this phenomenon.

Would you cut your maintenance calories by a third, to live longer? I'd love to know your thoughts.