June 20, 2005 — -- Meredith and Paul McGlothin have not found a potion or pill, but the two believe they have found a way to add years to their lives -- by eating significantly fewer calories.
"I'm trying to eat slightly less than my body would like during a course of a day," said Paul, a 57-year-old advertising executive. While most American men consume about 3,000 calories a day, he consumes just 1,900.
What the McGlothins are doing is not just a diet, it's called "caloric restriction" and it involves a radical lifestyle change. Most practicing CR cut calories by 10 percent to 30 percent, with the goal of living a longer and healthier life.
Caloric restriction is based on extensive animal research that has shown remarkable results. Monkeys and rats on the diet have much more energy than their counterparts that follow a regular diet, and rodents on the diet live about 30 percent longer than regular rats, research shows.
The McGlothins, who have been practicing caloric restriction since 1994, are sold on it, saying they are healthier and more energetic than when they started.
"I have more energy than I ever dreamed would be possible to have at any time in my life," Paul said.
And Meredith said that even if the diet does not significantly extend their lifespan, it is worth it now. "We are feeling better and we are able to work longer the way we want to," she said. "And we are hoping to add to our years of life, but even if it doesn't, it's healthy right now."
Dr. David Katz, a nutritionist from Yale University and a "Good Morning America" medical contributor, says the jury is still out on how healthy caloric restriction is for humans.
"The verdict is not in in terms of longevity, and the reason for that is that it will take 120 years to see if people can live 120 years on this diet," Katz said. "Short term, it improves cardiac risk factors and it has the prospect of extending life."
Katz said that caloric restriction has not been compared to the American Heart Association diet or the Mediterranean diet in terms of health benefits, but is instead being compared to the typical American diet.