Can you really be healthy and fat?

Being fit can counter some of the health risks linked to excess body fat.

Most researchers agree that too much fat increases your risk of coronary heart disease. In contrast, a lower level of fat is supposed to reduce the risk.

However, researchers from the Cooper Institute in Dallas and the University of Houston have shown that lean men had increased longevity only if they were physically fit [1].

Moreover, obese men who were fit were less likely to die from cardiovascular disease than lean men who were unfit.

The research team tracked a group of 21,925 men who had complete medical evaluations between 1971 and 1989. The men were split into three different groups based on their body fat levels.

• Lean (less than 16.7% body fat).

• Normal (between 16.7% and 25% body fat).

• Obese (above 25% body fat).

Fitness levels were tested using a treadmill endurance test. The men in the least-fit 20% of each age group were classed as physically "unfit". The rest were classed as being "fit".

During an average follow-up period of eight years, the results showed that aerobic fitness served to protect against some of the health risks associated with excess body fat.

• Men who were unfit but lean had a higher risk of death from cardiovascular disease than obese men who were fit.

• Not surprisingly, those with the highest risk of heart disease were obese and unfit.

The table below shows you the relative risk of death from cardiovascular disease in the different groups of men.

Relative risk is how much more likely individuals in a population are going to develop a condition based on what they eat or how they behave.

The relative risk for lung cancer in cigarette smokers is about 10, meaning that if you have that habit you are 10 times more likely to get lung cancer than someone who never smoked.

Bringing a relative risk of 2 down to 1 means that the incidence of a disease has been cut by half. But this does not mean anything definite for you as an individual. Relative risk is simply a statistic generated to compare large numbers of people.

Unfit men with a normal level of body fat, for example, have a relative risk of 3.0. In simple terms, this means they are three times more likely to die from cardiovascular disease than lean, fit men (who have a relative risk of 1.0).

TABLE 1. Relative risk of death from cardiovascular disease in lean, normal, and obese men with different levels of fitness.

One major limitation of the study was the fact that all subjects were white men, so the findings don't necessarily apply to all populations. However, the results do show that fit men are likely to live longer than unfit men regardless of body composition.

A study of more than 900 women also shows that when it comes to heart disease, being fit may be more important than being thin [2].

"Our study shows that the lack of physical fitness is a stronger risk factor for developing heart disease than being overweight or obese," says Timothy Wessel, a physician at the University of Florida who headed up the research.

The study involved 906 women whose health histories were tracked from 1996 to 2000. Seventy-six percent were overweight at the start of the study, when the mean age of the group was 58.

In addition to being measured for weight, the women were asked about their ability to do common physical activities at home, work and at leisure, such as climbing a flight of stairs, running a short distance or walking around the block without stopping.

During the study, 68 of the women died and 455 suffered a heart disease-related problem such as a heart attack or stroke.

When analyzed by categories of weight and activity, women who were at least moderately active were less likely to develop heart disease or related problems than women with low activity scores, no matter which weight category they were in.

"These results suggest that fitness may be more important than overweight or obesity for cardiovascular risk in women," the study concluded.

Bairey Merz, a physician at Cedars-Sinai Medical Center in Los Angeles and another of the study's authors, said that because physical fitness "has beneficial effects on many factors related to cardiovascular risk, including obesity, increased activity appears to be an ideal therapy for women with coronary heart disease."

Paul Campos, author of The Obesity Myth: Why America’s Obsession with Weight is Hazardous to your Health, also points out that fat active people are much healthier than the thin sedentary people and they are just as healthy as thin active people, indicating that activity levels are very important to health but that weight really isn’t.

A Harvard research team has also shown that lack of physical activity and being overweight are each independent risks for early death [3]. Together, they are a double whammy.

This isn't an endorsement for being overweight. People with the highest risk of heart disease are usually obese and unfit. But it does show that regular physical activity has health benefits even if you don't lose weight.

References
1. Lee, D.D., Blair, S.N., & Jackson, A.S. (1999). Cardiorespiratory fitness, body composition, and all-cause and cardiovascular disease mortality in men. American Journal of Clinical Nutrition, 69, 373-380
2. Wessel, T.R., Arant, C.B., Olson, M.B., Johnson, B.D., Reis, S.E., Sharaf, B.L., Shaw, L.J., Handberg, E., Sopko, G., Kelsey, S.F., Pepine, C.J., & Merz, N.B. (2004). Relationship of physical fitness vs body mass index with coronary artery disease and cardiovascular events in women. Journal of the American Medical Association, 292, 1179-1187
3. Hu, F.B., Willett, W.C., Li, T., Stampfer, M.J., Colditz, G.A., & Manson, J.E. (2004). Adiposity as compared with physical activity in predicting mortality among women. New England Journal of Medicine, 23, 2694-2703