Two UW monkeys. Lean, youthful and extremely hungry on the left, and chubby and aging faster. © 1998, Wisconsin Regional Primate Research Center, Photos by Jordana Lenon.
What about their minds?
It's well documented that aging rats on caloric restriction can learn mazes faster than free-feeding rats. That made us curious about the monkeys' state of mind. But George Roth of the National Institute of Aging, who is testing the monkeys' behavior, says progress is frustrating. "It's taking a long time to train the monkeys to do the tasks," he says. "We hope to get faster, but it's agonizingly slow" and he has no results to report.
Roth can say that the restricted monkeys are more active, "particularly around meal times. We know they're hungry, and are anticipating their food." And are the monkeys happy? Unfortunately, they're not saying.
The point of the research is not to propose a similar diet for humans, Roth points out. Given that people have trouble staying on much laxer diets, it's unlikely that many people would stick with a 30 percent slash in calories. Although "current findings strongly suggest that caloric restriction might extend lifespan," and a healthy lifespan, Roth says, "I wouldn't recommend anything to humans based on this study."
Human guinea pigs
Still, a few people have adopted this stringent diet. Some report a constant gnawing of hunger in the stomach, but New York freelance writer Richard Elixxir, 42, who restricted his diet to 1,200 calories per day about 20 years ago, says caloric restriction is easier than it seems -- if it's not approached in a "fundamentalist" manner.
"The biggest problem is that most people try it in a way that's not doable in a real-life situation," he says. "You don't have to be a perfectionist, you don't have to hit 100 percent of every nutrient every day." In his yet-to-be-published book, "The Elixxir Program: How to Stay Young, Slim & Healthy," Elixxir also recommends taking a "day off" every week or two to eat in the old, unrestricted style.
After 20 years of restriction, he says the benefits are obvious -- with blood pressure and cholesterol levels characteristic of a twenty-something, and a much younger appearance. "It's very reinforcing, when you go to a reunion and everyone is amazed because you look so young."
Although it sounds intriguing, The Why Files is not about to endorse any eating schedule that forbids a daily ice-cream sundae.
The goal of the caloric restriction research is not to invent another reason to feel guilty about your diet, Roth says, but to "solve the mechanism by which this produces longer life span, and target that pharmacologically, so you could trick the cells and still get to eat." (That reminds us of some fast fat fixes we covered. Or check our story on human obesity)
One thing's for sure: restricting calories seems to starve tumors.
