strongernow
08-28-2004, 09:00 AM
(National-NBC) Aug. 27, 2004 - Yo-yo dieting isn't just frustrating. New research shows it may harm your immune system.
Researchers studied more than 100 overweight women and found those who lost at least ten pounds five or more times had one-third less natural killer cell activity than women who were not repeat yo-yo dieters.
Natural killer cells attack viruses and may protect against cancer and are an essential part of the immune system.
Women who reported maintaining their weight for five or more years had 40 percent greater natural killer cell activity than the women who's weight was stable for less than two years.
Researchers note that previous work shows exercise may blunt the negative effects of repeat weight loss on the immune system. All of the women in this study were sedentary.
The research was conducted at Fred Hutchinson Cancer Research Center and published in the "Journal of the American Dietetic Association."
Researchers studied more than 100 overweight women and found those who lost at least ten pounds five or more times had one-third less natural killer cell activity than women who were not repeat yo-yo dieters.
Natural killer cells attack viruses and may protect against cancer and are an essential part of the immune system.
Women who reported maintaining their weight for five or more years had 40 percent greater natural killer cell activity than the women who's weight was stable for less than two years.
Researchers note that previous work shows exercise may blunt the negative effects of repeat weight loss on the immune system. All of the women in this study were sedentary.
The research was conducted at Fred Hutchinson Cancer Research Center and published in the "Journal of the American Dietetic Association."