Yo-yo dieting weakens immune system, says study

This is further evidence supporting slow, sustained weight loss rather than crash diets or trying to "lose ten pounds in ten days." If you want to attain and maintain a healthy body weight, persistence, not immediate results, is the key. If you lose more than 1-2 pounds a week, you're probably overdoing it.

• In the last four years, she lost 60 pounds on a liquid diet, 35 pounds with a combination of herbal weight-loss pills and four hours of daily exercise and 15 pounds on the Atkins plan.
• "I've been dieting forever," says the 51-year-old secretary for the city of Los Angeles.
• Carrying 210 pounds on her 5-foot, 7-inch frame, Erie's aware of studies showing that weight reduction decreases the risks of diabetes and other illnesses.
• But diet and nutrition experts are concerned about the potential health consequences for people such as Erie who repeatedly lose and regain pounds.
• Nutrition educators at the University of California, Berkeley, recently reported that women who began dieting before age 14 were not only heavier but also were more than twice as likely to have dieted more than 20 times than women who began restricting their calories later.
• Lead author Joanne Ikeda said those who begin this pattern of losing and regaining pounds before puberty could disrupt their physical development.
• Now, there's new evidence that yo-yo dieting may weaken the immune system.
• Researchers at the Fred Hutchinson Cancer Research Center in Seattle studied natural killer cells, which attack viruses and cancers, in a study of 114 obese, sedentary women ages 50 to 75.
• Among women who had lost weight at least five times, natural killer cell function dropped 30 percent, researchers reported.
• At a time when an estimated 50 percent of American women and 25 percent of American men are either dieting or thinking about dieting, such findings reinforce the wisdom of sticking with a sustainable weight.