Eat less, live longer?

• By DEBRA LEMOINE
• Advocate staff writer
• Published: May 19, 2009 - Page: 1D

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Stephen Knox needed a lifestyle change.

The wireless phone salesman, 28, watched his weight creep up as he got older, exercised less and ate out more.

“I found myself in a vicious cycle,” he said.

Knox enrolled in a study at Pennington Biomedical Research Center that aims to determine if eating fewer calories can slow down human aging. Although not designed as a weight loss study, Knox and other participants are dropping pounds as a result of the prescribed calorie restrictions.

With the aid of intensive nutritional counseling from Pennington, Knox eats no more than 2,100 calories a day, 25 percent fewer calories than his former habits. As a result, he has lost 25 pounds over the past 18 months.

“I have more energy, and I feel a lot better now,” Knox said.

Following the diet is about choices, he said. If he makes healthy food choices, then he is satisfied and not hungry. If he eats a high-calorie dessert, then he tries to maintain his calorie limitations by cutting back later in the day, leading to hunger.

“It hasn’t been 100 percent easy the whole time,” Knox said.

The discipline of Knox and 50 other Baton Rouge area residents is contributing to scientists’ understanding of biological aging in this second phase of the landmark study on aging known as Comprehensive Assessment of the Long Term Effects of Reducing Intake of Energy (CALERIE) trial. Pennington is seeking additional volunteers for the study.

Funded by a $50 million grant by the National Institute on Aging, scientists at three research centers seek to verify in humans that reduced caloric intake affects the healthy lifespan, said Eric Ravussin, a diabetes and obesity researcher who leads the multisite study at Pennington.

Researchers are unsure why humans age and die, but one theory suggests that the byproducts of cells’ use of oxygen to burn food for energy damage cells. This damage can be repaired by the body, but the damage builds up over the years until eventually more and more cells die.

Lifestyle choices, such as getting little or no exercise and gaining weight, also are known to affect the onset of such diseases as cancer, dementia, heart disease and diabetes.

“We call these the diseases of aging because they seem to be inevitable,” said Leanne Redman, another Pennington researcher working on the CALERIE study. “One of the big advantages of caloric restriction could be the delay of these diseases or prolonging the health span.”