In a windowless, climate-controlled chamber on the third floor of the Dedman Life Sciences building at Southern Methodist University, thousands of fruit flies are on a diet so someday you won't have to be.
The crumb-sized insects, weighing just 1 milligram each, live in slim glass and plastic tubes—100 flies per—arranged in neat rows in 10 shallow cardboard boxes stacked on shelves, one on top of the other, like little fly condominiums.
The landlord of the flies is 37-year-old scientist Johannes Bauer, Ph.D. New to the biology department at SMU, an up-and-coming center for aging research, Bauer feeds his flies every other day with a mixture of sugar and yeast as he studies the effects of calorie restriction on the flies' health and longevity. In experiments he started at Brown University, he's found that consuming 30 to 50 percent fewer calories daily allows the Drosophila melanogaster fruit fly to live 10 to 40 percent longer than its natural lifespan—the equivalent in humans of living 120 years or more. Flies fed less are more alert, says Bauer. They're more active in almost every way, except they're not as fertile. Female flies share the tubes with males anyway because, says the scientist, "we want them to have some fun."
Semi-starvation doesn't sound like a party, but calorie restriction—a scientific term meaning under-nutrition without malnutrition—is now being touted as the latest fountain-of-youth secret for extending the human "health span" and possibly the life span. Gerontologists, oncologists, biochemists and biologists like Bauer, engaged in calorie restriction studies on lab animals, believe they've found an effective way to stave off cancers, heart disease, diabetes, arthritis, Alzheimer's and many other ailments. Staying hungry and living lean, say some researchers, is the only mechanism scientifically known to slow down the aging process and prevent age-related illnesses.
This comes as little surprise to children's book author Shannon Vyff, 33, of Round Rock. For the past eight years, she has been a member of the Calorie Restriction Society, a loosely connected (mostly through Facebook) international "community" devoted to austere eating for healthy purposes.
Vyff is now one of the society's most vocal supporters. She discovered calorie restriction after having three children in her 20s and hitting 200 pounds after the third. "I started searching online for diets and came across calorie restriction, and it made a lot of sense," says Vyff, 5-foot-10-inches and now 130 pounds, up from her lowest of 117. It took her just six months on CR to lose 85 pounds. "There was an adjustment period at first. But I started to like the foods that were healthy for me. The hardest thing was cutting out some of the things that I loved eating, like pasta and breads."
Calorie Restrictors—sometimes called CRONies, for Calorie Restriction/Optimal Nutrition—eat between 10 and 30 percent fewer calories than the typical adult, avoiding any foods high in fat, sugar or starch. Vyff now eats once a day, usually a lean chicken breast poached in water, some steamed broccoli or squash and maybe a glass of fresh orange juice. She eats red meat once every two weeks and prefers it cooked rare. Her daily calorie count hovers around 1,200 if she's not exercising; 1,600 to 1,800 if she runs 5 or 10 miles on the treadmill. She's also on a local roller derby team. When she's in training for that, she might help herself to a few extra morsels. Her favorite treat: six raw walnut halves and three Ghirardelli chocolate chips.
She credits CR with helping her pass her latest driving test without glasses for the first time. Her chronic knee pain disappeared, and her energy level zoomed, she says. Vyff's husband, Michael Trice, 32, also follows the CR plan, with occasional lapses for desserts shared with their kids. (CR is not recommended for children or teens, even if overweight.)
And do they think living on less food will let them live to be 100 or older? "Why not? If everyone started following calorie restriction, they could extend life by decades and be healthier in the middle years."
Adherents to calorie restriction and its cousins, raw foodism and veganism, tell similar stories about the positive effects, other than weight loss, of their eat-this/not-that regimens. They start to look younger than their years (something observed in calorie-restricted lab animals). Their chronic headaches, arthritis pain and sleep disorders go away without medication. They feel stronger, happier, more spiritually aware—as if a brain fog has lifted. Some report bursts of creative energy. Others describe a feeling of calm that envelops them after going with fewer calories for only a short time.
There is a scientific explanation for all of this. Reducing caloric intake, even by as little as 10 percent a day (skipping that extra helping of potatoes), sends the body's cells into a low level of stress that makes them strong when high stresses occur—much the way moderate stress caused by exercise improves people's health. "Restricting calories just a little bit puts your body in a state of stress, which makes you a little bit healthier," says Bauer.