Some recent research has suggested that you can be "fat, but fit." But a large new study finds that the negative health risks caused by obesity are not offset by being physically fit. Men of healthy weight at any level of fitness had a lower mortality rate than obese men who were aerobically fit.
To come to this finding, researchers in Sweden studied the records of more than 1.3 million Swedish men who had been drafted into the military at about age 18 between 1969 to 1996. All the men had their fitness levels evaluated at the time by taking a test where they cycled to the point where they were exhausted. The men were then followed for an average of 29 years.
Those men who had been in the highest 20% of the group for fitness when they were tested for the military had a 51% reduced risk of dying prematurely from any cause compared with those in the lowest 20%. However, men of normal weight, no matter what their level of fitness, had a 48% lower risk of premature death from any cause than did obese men who were in the highest 25% of fitness levels. Aerobic fitness was associated with a reduced risk of death from any cause in the men who were normal weight or overweight, but the benefits were reduced in those who were obese.
Deaths associated with suicide and alcohol and drug abuse were most commonly seen among men with lower aerobic fitness. The researchers also found a strong link between trauma-related death and low levels of aerobic fitness.
Dr. Peter Nordstrom, a professor of geriatrics at Umea University in Sweden and an author of the study, told The New York Times that the results should be interpreted with care. "The results show that if you are fat and fit you still have a higher risk of death," he said. "But given that these data are observational, one should be careful about drawing any conclusions. Is it a causal relationship, or are there other things involved?"
The study appeared in the International Journal of Epidemiology.