Shape, not weight, indicates cardiovascular health (1/29/98)
Are you shaped like an apple or a pear? Do we have to change our body image through exercise and diet to remain healthy?
"If you are shaped like an apple," says Colleen S. Keller, PhD, professor in the department of family nursing care at The University of Texas Health Science Center at San Antonio, "you may be at risk for cardiovascular disease."
"Our research group shows that women from different ethnic groups have body fat located in different areas of the body," says Dr. Keller. "Black and Hispanic women have classic gluteal femoral deposits -- they are shaped like pears -- and native American women have classic apple shapes. Of course, in some Indian tribes the incidence of heart disease and diabetes is very high, but we can't tell by looking at a woman on the street if she is at risk for heart disease."
Dr. Keller initially worked with normal weight minority women and found that they had large fat deposits even when they were not overweight -- they were overfat. "Instead of body fat, it's the fat distribution that increases a woman's risk of cardiovascular disease or other chronic illnesses," she says. "Most women who are shaped like apples are very much at risk. However, in a New York study Caucasians and African-Americans were compared and African-Americans had 22 percent less intra-abdominal fat than did white women, demonstrating definite ethnic differences. These findings also have been demonstrated in our work here at the Health Science Center in Mexican American women."
Dr. Keller has researched the subject of body fat versus health for the past decade. Currently, she is examining the dose response of exercise in premenopausal Mexican-American women. "Lifestyle changes targeted at weight loss are difficult for many individuals, particularly for some ethnic groups and for women from poor socio-economic backgrounds." "People who are poor, regardless of color, find it more difficult to go to a health care provider," Dr. Keller says. "They have less trust, and they find it difficult to accept a value system different from their own."
She says that in her clinical practice and in her research, she has worked with women who have a difficult time just getting up in the morning. "Because their lives are so painful, our interventions have to be amenable to their life style, that is, very integrated into the way they live," Dr. Keller says. "So rather than the usual prescription, to exercise 30 minutes three times a week with a dietary change, we encourage them to exercise as they go about their daily tasks. We know these women aren't going to give up their ethnic food, especially during holidays.
"There has been so much publicity about changing your body image and food as an addictive substance," Dr. Keller says. "When we think long- term we should consider what can be done from a public health perspective, regardless of body fat, to keep people fit. Being overfat doesn't necessarily mean poor health.
"In a recent *Time* magazine story, women who were as much as 50 pounds overweight had healthy cholesterol levels. They did aerobic activity every day and they were very fit, even though they were fat," she continues. "There isn't enough known about genetics and body composition of women to draw correct conclusions," Dr. Keller says. "In spite of all we know about exercise and weight loss, it is still not clear how much or what 'dose' of exercise will reduce body fat and alter fat distribution in women."
Sixty percent of our energy is spent while we sit or at a resting metabolic rate. According to Dr. Keller when we diet we lower that rate, which means when we eat less food our bodies have a rebound effect. Any food that's eaten in addition to that needed by the body with a reduced metabolic rate is going to turn into fat.
"It takes exercise to preserve lean tissue," Dr. Keller explains. "But we don't know how much exercise alone will cause a reduction in weight or in body fat. From a public health perspective, people don't work out at high intensity and continue to do so. This just isn't real life."
So do we need aerobic exercise to stay healthy?
"No," says Dr. Keller, "but we need duration. The greatest thing we can do for our health is to get up off the couch. Take the stairs instead of the elevator. Park farther away from work or from the grocery store and incorporate these changes into your life style. In a recent study from the Cooper Institute in Dallas, a group using formal exercise and a group increasing their daily activities were compared.
"The test subjects who did aerobics had better results, initially," Dr. Keller says, "but they didn't sustain their activity. Eventually they tapered off or quit altogether. The people who changed their life styles didn't show an initial cross-over but their long-term activity stayed higher. There was a big difference in results at the end of two years. Those with life style changes were definitely healthier.
"The best and easiest way to lose fat is not to accumulate it in the first place. More and more, we are going to see prevention," the researcher concludes, "both in the home and in the workplace. The folks with the gym membership drop out. We just can't live that way indefinitely. We now know that disease usually is a result of life style, so we must change our life style to stay healthy."
Contact: Jan Elkins, (210) 567-2570