MADISON, Wis. -- Could eating less extend your life?

New research from the University of Wisconsin-Madison indicates that it seems to work for monkeys. A 20-year study of rhesus monkeys found cutting calories by almost a third slowed their aging and fended off death.

It backs up what scientists have long known about mice, worms and flies, that their lifespan can be extended by deep, long-term cuts in what should be normal consumption.

And the study found the monkeys didn't just live longer -- they were healthier.

Richard Weindruch, a professor of medicine at UW-Madison, spent two decades studying the effect of caloric restrictions on rhesus monkeys.

While some monkeys were permitted to eat freely, another group in the study was given 30 percent fewer calories.

"It's not really about comparing it to gluttony. It's really about comparing normal intake to the restricted one," said Richard Weindruch, a professor of medicine at UW-Madison, who spent two decades studying the effect of caloric restrictions on rhesus monkeys.

Weindruch said the calorie-cut monkeys had less than half the incidence of cancerous tumors or heart disease as the monkeys who ate normally. Brain scans showed less age-related shrinkage in the dieting monkeys. They also retained more muscle, something else that tends to waste with age.

"They look younger longer than do the animals fed conventionally, and there are no indications that they are unhappy or their personalities have changed," Weindruch said.

The question for scientists now is whether that kind of calorie-cutting would have a similar effect on humans.

Some people consuming calories at the Memorial Union terrace Thursday said the findings seem to make sense.

"Well, it makes a great deal of sense and I believe it. But whether or not I'll practice it, I don't know. I just had a dish of chocolate ice cream," said Union terrace visitor Emily Ford, laughing. "I never gave it much thought, but I'll pay more attention to those monkeys."

Raffi Mesdjian said moderation is helping him celebrate a 50th birthday and that the study is a reminder to eat healthy.

"No smoking, not much drinking, eat healthy and play soccer has been my key so far," Mesdjian said. "I hope I can live another 50 years if I'm healthy like this, and I hope my friends are around me to enjoy life."

The study on monkeys living at the Wisconsin National Primate Center appears in the journal Science.

Researchers said it's too early for the study to prompt changes to the government's calorie guidelines.

Researchers warned that those blanket calorie recommendations might not be an accurate guide for everyone. Restricting calories could lead to a deficiency of nutrients, so researchers are also urging everyone to consult a nutrition expert before making changes to their diet.