Dennis Brooks, 60, became interested in nutrition during the last two years of his 20-year Army career. For years, he had struggled to keep his weight down and then, after retiring, he was in an auto accident and gained even more. To address his frustration, Brooks began skipping breakfast. Then, pleased with his modest weight loss, he began forgoing lunch as well. Now he eats on alternate days (soup, salad, fish or lean meat, vegetables, nuts and occasional deserts) and only drinks water on the other days.
"I have found that on the fasting days if I eat anything it triggers more eating. But if I don't eat anything, I don't have an appetite," says Brooks, who lives in Hawaii. "On the next day, I have what I call a controlled binge."
Brooks has lost 50 pounds, gained energy and says his blood pressure and cholesterol levels have improved markedly. He recently published a book about his experience called "The Skip-a-Day Diet System."
Kathleen Flinn fasted one day each week from 1999 to 2003 while working as a restaurant reviewer in Europe. But after she enrolled in cooking school at Le Cordon Bleu in Paris, she stopped fasting and gained 30 pounds.
Now a food writer in Seattle, she recently resumed a once-a-week fast, skipping dinner on Mondays and consuming only fruit and vegetable juice and broth on Tuesdays. "I tried to diet and exercise, but I felt I was missing a piece of the puzzle," says Flinn, 41, chairwoman of the food writers, editors and publishers section of the International Assn. of Culinary Professionals. "That was one of the reasons I went back to fasting. I find that, even after one day, my taste is more acute. It makes me more aware of what I'm eating. You learn to understand when you're really hungry and when you're just thirsty or tired."
Flinn admits she is hungry on fasting days and keeps mentally busy to avoid thinking about food. On Wednesday morning, she dips a cautious toe in the kitchen.
"I try not to gorge myself," she says, adding that she lost 7 pounds in January. "I think where people make the biggest mistake is when they come off the fast. They are incredibly hungry. It's the part of the fast that takes the most discipline."
Most people who practice calorie restriction say they find it easier after a few months, says Bob Cavanaugh, managing director of the nonprofit CR Society, which assists people with the practice. "A lot of people are trying to ward off the disease of aging," he says. "But our members run the gamut. Some eat once a day, some eat every other day, some are vegans, some eat 1,800 calories each day. What we are all looking at is the result."
Dan Golden, 46, began practicing intermittent fasting almost 15 years ago, intrigued with research that linked calorie restriction to increased life extension. For many years, the Hacienda Heights man, who works as a librarian, ate a large meal four days a week and had fluids on the other days. He eventually became too fatigued on the days he was fasting. Now he eats about 1,800 to 2,000 calories a day on a diet high in fruits, vegetables, rice and beans.
"I found I no longer have an interest in sugary foods," he says. "It's not because I'm snooty and won't eat it. I just don't have an interest in it."
People who fast regularly don't do so foolishly, Cavanaugh says. Many take nutritional supplements and monitor their diets to avoid deficiencies and maintain weight.
Calorie restriction shouldn't result in excessive thinness, experts say. It's not appropriate for children or adolescents, who are still growing, or people with serious illnesses. And those with diabetes or heart disease should adopt the diet only after consultation with a doctor.
"You can overdo calorie restriction just like you can overdo almost everything," notes Mark P. Mattson, chief of the laboratory of neurosciences at the National Institute on Aging.
Those who use intermittent fasting hoping for a quick weight loss may have disappointing results, experts add. The body's general weight is established through genes and chronic eating patterns, says Dr. Marc Montminy, a researcher at the Salk Institute for Biological Studies who studies fasting. After weight loss, he says, "your body will very quickly try to reestablish your set point. If you lose weight more gradually, maybe this gauge can be reset."
Many people find that cutting back on calories causes their metabolism to slow and weight loss becomes difficult, says Andrea Giancoli, a Los Angeles-based nutritionist and spokeswoman for the American Dietetic Assn.
"The real danger of fasting when it comes to weight loss is you risk slowing down your metabolism, and that defeats the whole purpose," she says. "As soon as you start eating again, your body wants to store those calories."
But Giancoli praises efforts to become more thoughtful about food. "People say that, psychologically, fasting can help reset your feelings about your relationship with food. If that helps you develop more healthy dietary patterns, that's OK. But if you fast one day a week, the other six days of the week you have to eat a balanced diet and not overeat."