Eating Less to Live Longer

Dec. 5, 2003 -- -- For Darren and Shannon Vyff, dinner is family time. But Shannon's is a very different meal. In fact, it's her breakfast and lunch too — it's the only food she eats all day.

Vyff consumes 1,600 calories a day, about one-third less than most American women consume. This has helped her lose 85 pounds after the birth of her third child.

Yes, it's a diet. But the 28-year-old Oregonian isn't severely cutting calories to get a movie-star body. She doing it in the hope that she'll add years to her life.

"I'm hoping this will extend my life to a time where science has eradicated the greatest killer, which is aging," she said.

Can your diet slow the aging process and help you stay young forever? That's the theory behind Calorie Restriction, or CR, a phenomenon practiced by an estimated 1,000 individuals around the world 3 cut food drastically, keep the nutrients in your diet, and live longer.

Going Easy on Your 'Engine'

Dr. David Katz of Yale University, an expert in chronic disease prevention through nutrition, compares the CR regime to not pushing your car too hard.

"If you think of putting lots and lots of fuel into a car because you're driving it fast and hard, you're going to wear out the parts," Katz said, "Well, there really is a wear and tear price to pay for burning fuel in the human body as well."

Katz says if we get by on less fuel, or food, we'll be less apt to wear out our bodies, and, he says, "potentially add decades at the far end of the life span."

Back in 1988, when ABC News first reported on CR, we met with Dr. Roy Walford of the University of California, Los Angeles. He was working with lab mice, which he had placed on a special low-calorie, high-nutrient diet. The mice lost weight and outlived their companions by more than 50 percent.

"If the translation is direct," Walford told ABC News, "as from mouse to man, then we could live to be 175."