A new study has found that the dieting habits of teenage girls may make them more likely to become obese as adults.
The study, published in the June 2004 issue of the Journal of the American Dietetic Association, surveyed 149 obese women from 2000 to 2001. All the participants had attended two annual conferences for large women, and all had a body mass index (BMI) of 30 or higher, classifying them as having crossed from overweight to obese. Their mean BMI (a ratio of weight to height) was 46; some weighed more than 500 pounds.
More than 80% unable to maintain permanent weight loss
The researchers found that women who started dieting before age 14—two thirds of all the women surveyed—were more than twice as likely to have dieted more than 20 times compared to women who began dieting later. More than 8 in 10 of those who began dieting before age 14 said they were never able to maintain permanent weight loss. It's not known how much the women weighed as teens, but most reported they weren't severely overweight at the time.
May disrupt metabolism
The reason for the link isn't entirely clear. But it's possible that early dieting may disrupt the metabolism of teen girls, setting them up for obesity later in life.
There is some thought that continuous dieting, particularly with severe caloric restriction, forces the metabolism to be more efficient—to lose less energy as heat and capture more for fueling the body. And the net result is that it is harder to lose weight and keep it off.
Scientists stress that the problem is that fad diets often focus on quick weight loss, which requires great reductions in calories, instead of the gradual and steady weight loss recommended as healthy by physicians.
1. J. P. Ikeda; et al., “Self-reported Dieting Experiences of Women with Body Mass Indexes of 30 or More,” Journal of the American Dietetic Association, June 2004:104: 6: 972.