The State of Our Health - Women's Health: Weighty Trends

The graphic shows the stately march of obesity over the past 30 years or so. Data for 1999, from the National Health and Nutrition Examination Survey (NHANES) conducted by the Centers for Disease Control (CDC), is still preliminary, and details by sex and race are not yet available. (Obesity trends for men as a group are shown here for illustrative purposes only. More specific information on men is provided in other panels.)

How is obesity measured? Divide your weight by your height in inches; divide the result by your height in inches again; multiply the result by 703. A person 5 feet and 7 inches tall, weighing 134 pounds will have the following calculation:

134 / 67 / 67 x 703 = 21.

In this calculation, 5 feet and 7 inches have been converted to 67 inches. The resulting value, 20.985, rounded to 21, is the so-called Body Mass Index or BMI. A BMI of less than 25 is considered to be healthy weight. A BMI of 25 to 29.9 is considered to be overweight. A BMI of 30 or above indicates obesity.

The metric calculation is to divide the body weight, in kilograms, by metric height squared. The same person, above, weighs 60.8 kg and has a height of 1.7 meters. The formula is therefore 60.8 / 1.7²= 21.

A higher percentage of men are overweight than women (39.9% men, 25.7% women in the 1988-1994 period), but, as the graphic shows, a higher percentage of women are obese. The percentage of African-American women who are obese is much higher than the percentage of white women (39.1% and 24.3%). Obese black and white men represent almost the same percentage of the male population (21.1% and 21.0%)³.

We're eating the wrong kinds of food and we're not moving around enough. First the automobile, then the TV, finally the Internet. Obesity was trending up, but at a slow rate, in the 1960 to 1980 period. Then it started heading up steeply, growing 54% in about a decade and another 16% in the next five years or so. Not surprisingly, the CDC labels this phenomenon a public health epidemic.

Obesity is a woman's health issue because more women are obese and hence at risk. The relative risk of diabetes increases by about 25% for each BMI index point above 22. Sixty-seven percent of people with Type II diabetes (the most common form) have a BMI of 27 or higher; 46% of these women are obese. Among obese women, 32.2% have high blood pressure, 24.7% have high blood cholesterol.

More information on weight problems and obesity is presented elsewhere in this book. We note here the troubling trend toward more body weight, with its adverse consequences and relationship to heart disease, the leading killer of women (and men). Once the 1999 survey data are available, it is almost certain that women, as before, will be leading the parade, achieving (if that's the right word) very high obesity scores.

¹ Sources: Centers for Disease Control and Prevention. National Center for Health Statistics. Division of Health Examination Statistics. Unpublished data. Online. Available: http://www.cdc.gov/ June 1, 2002. Obesity and disease correlations from "Statistics Related to Overweight and Obesity." National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Online. Available: http://www.niddk.nih.gov/health/nutrit/pubs/statobes.htm.