In a world of rampant obesity, how relevant is calorie reduction as an anti-aging tool?

Read any newspaper and you'll soon see a story on the obesity crisis. Walk down pretty much any street and you'll see it with your own eyes. People are killing themselves (albeit slowly) bite by bite. With this in mind, how relevant is a longevity technique that calls for severe calorie restriction?

Not much, yet. Even a disciplined and well-trained athlete would have trouble maintaining the lifestyle required to get the theoretical benefits of calorie restriction. And even if one could, would it be worth it? Hard to tell. But what if they were able to distill the biological changes that result when one is in a calorie restriction mode into a pill? Now that would be interesting.

According to a recent article in the Wall Street Journal (may require registration/fee) scientists are currently focusing on a substance in red wine called resveratrol. So far it has been successful in boosting the lifespans of yeast, fruit flies and roundworms. There is even indication that it may have worked in a short-lived fish.

Some researchers believe antiaging drugs could also improve health in late life -- rather than prolong misery -- letting people stay in relatively good shape until a swift demise.

What does this mean to us today? Not much.

Resveratrol is available as a dietary supplement, but to replicate the doses used in the studies, a person would need to take scores of pills a day. The dietary supplements haven't been tested in clinical trials, so their efficacy isn't proven, nor is it clear what dose might make people live healthier or longer. And although they seem safe at modest doses, megadoses may not be.

In short, there is a good reason to reduce calories, which is to avoid obesity. Beyond that it is immense speculation. And the search for the Holy Grail continues.