Weight Gain Risk In Women Linked To Key Stages Of Life

Studies Focus on High Risk Periods for Weight Gain in Women and Explore Prevention Strategies

Long Beach, CA – October 31, 2000 Women may be especially vulnerable to weight gain during three key periods of their lives, according to research presented here at the annual meeting of the North American Association for the Study of Obesity (NAASO). Investigators examined the causes of weight gain in women at the beginning of their menstrual cycle, after pregnancy and after menopause.

"The prevalence of obesity in women has almost doubled in the last 20 years. Therefore, identifying key stages and causes of weight gain will be critical for developing prevention programs to stop or slow down this trend," said Charles Billington, M.D., president elect of NAASO and professor in the Department of Medicine at the Minneapolis VA Medical Center, Minneapolis, Minn.

In young girls, early menarche (the onset of menstrual cycling) may operate in the development of obesity. Support for this notion comes from two studies, conducted by researchers at Tufts University School of Medicine, Boston, Mass. These studies suggest that early menarche operates mainly as an intermediate on the pathway to later obesity. Early menarche may also contribute independently to increase the risk of later obesity. Moreover, other studies have established early menarche as a risk factor for breast cancer, and have also been associated with cancers of the reproductive system.

"Puberty, the hormonal transition of adolescence, has been identified as a potentially critical period in the development of obesity," said Aviva Must, Ph.D., associate professor of the Department of Family Medicine and Community Health, Tufts University School of Medicine, Boston, Mass, the lead investigator. "If early menarche were established as a critical period, obesity prevention and treatment strategies could be better targeted."

Weight retention following pregnancy may be a factor in the obesity of young women, according to an overview of research, presented by researchers at the University of Alabama at Birmingham. While most women experience a modest weight gain after pregnancy, obese women are at risk for substantial weight gain. In addition, the data indicates that African American women are at greater risk than Caucasian women.

"Weight gain after pregnancy may reflect changes in lifestyle behaviors rather than physiological changes associated with giving birth," said Delia Smith West, Ph.D., associate professor of Medicine, University of Alabama at Birmingham, Birmingham, Ala. "Obesity prevention programs that focus on changes in diet and physical activity patterns offer promise for reducing weight retention after pregnancy."

Weight gain during menopause may be significantly prevented by long-term changes in dietary intake and increased physical activity, according to findings of the Women's Healthy Lifestyle Project, a five-year, randomized clinical trial, funded by the National Institutes of Health.

"Weight change in the older woman may be more strongly associated with aging than with menopause. However, post-menopausal women have higher levels of body fat and central adiposity than other women the same age," said Laurey R. Simkin-Silverman, Ph.D., assistant professor of Epidemiology and Psychiatry and Health Services Administration, Department of Epidemiology, University of Pittsburgh, Pittsburgh, Penn., who presented the study. "The weight that many women gain during menopause is particularly troubling because it is associated with increased cholesterol, high blood pressure and insulin resistance."

The Women's Healthy Lifestyle Project included 535 pre-menopausal women who were randomly designated to either a behavioral lifestyle intervention group, in which they were on a low-fat, reduced-calorie diet and physical activity, or to an assessment-only control group. Four and a half years into the study, twice as many women in the intervention group were at or below their original weight (an average weight loss of 0.18 pounds) compared with the control group, which had progressively gained weight (an average weight gain of 5.2 pounds) over the course of the study. Overall, the study demonstrated that both physical activity and reducing saturated fat in the diet are key to preventing weight gain.