It’s a long-standing debate — can you be fat and healthy as long as you are fit, or is it bad to be fat, full stop? The debate came to New Zealand earlier this month when Professor Steven Blair presented at a conference at the University of Otago on the crucial role of physical activity in the prevention and management of overweight and obesity.
Commenting in the Otago Daily Times, Prof Blair states, ’I’ve been studying the cause of death in a select group of people for over 30 years and I’ve found that a sedentary lifestyle accounted for more deaths than anything else.” Prof Blair said he, himself, was overweight, but maintained he was healthy because he was fit.
Prof Blair argues in his research that that regular physical activity clearly attenuates many of the health risks associated with overweight or obesity.
So, what’s really the more important determinant of health — fitness or fatness? There have been many research studies on this very topic over the years. A study in the New England Journal of Medicine in 2004 found that both increases in adiposity and reduced physical activity were strong and independent predictors of death among women.
A more recent study on physical fitness, adiposity and metabolic risk factors in young college students found that both increased body fatness and decreased physical fitness were associated with metabolic risk, and concluded that it is important to encourage both a healthy weight and fitness since each play important and independent roles in biochemical parameters associated with increased chronic disease risk.
However, a recent systematic review, which looked at 36 publications, suggests that the risk for all-cause and cardiovascular mortality was lower in individuals with high BMI and good aerobic fitness, compared with individuals with normal BMI and poor fitness. In contrast, having high BMI even with high physical activity was a greater risk for the incidence of type 2 diabetes and the prevalence of cardiovascular and diabetes risk factors, compared with normal BMI with low physical activity. The authors do conclude, however, that their results may not apply to those with a BMI >35.
There is lots of evidence to point to obesity as a risk for chronic disease and there is also significant evidence for the beneficial effects of exercise. Personally, I think the best scenario for optimal long-term health is to stay within a healthy weight range and to be physically fit.