In previous posts (such as here and here) I have written about how the impact of ‘excess’ weight on health seems to have been, well, overstated in both men and women. More evidence to this effect emerged this week on the publication of a study of nearly 7000 American men with an average age of 58. The study, conducted in California and published in the American Journal of Medicine, assessed the health of men who had been referred for the investigation of possible heart disease. The study participants were assessed through, amongst other things, a weigh-in and fitness testing, after which they were followed for an average of 7½ years.
Over this period, about a quarter of the men died. The researchers then looked at the risk of death between different ‘bandings’ of weight. Compared to individuals in the ‘healthy’ weight category (body mass index 18.5-24.9), individuals in the ‘obese’ category (BMI 30 or more) were 22 per cent less likely to die over time of follow-up. And this reduction in risk was found to be statistically significant.
It is possible that individuals who are obese are, compared to slimmer individuals, more likely to be unfit and have other risk factors for heart disease such as diabetes. When the researchers accounted for such factors (in an effort to make weight the only differentiating factor between the groups) the obese men were found to be at a 35 per cent reduced risk of death compared to their considerably slimmer counterparts.
The study authors are keen to point out that the results of this study are not a mandate for the encouragement of obesity. They say that this group consisted of older men with symptoms of heart disease, and therefore do not know whether the results are applicable to the population at large.
I suppose that’s fair enough, but whichever way you look at this most recent research, it seems yet again to suggest that the body mass index is pretty hopeless as a marker for health.
For more on why the BMI is fatally flawed as a health measure, see here.
1. McAuley P, et al. Body mass, fitness and survival in veteran patients: another obesity paradox? The American Journal of Medicine. 2007 120(6):518-524