Healthnotes Newswire —Men between the ages of 40 and 65 years have an increased death rate if they are obese, according to a study published this month in the American Journal of Epidemiology.¹

In this study, researchers followed nearly 40,000 American male healthcare professionals aged 40–75 years for a ten-year period. At the beginning of the study, height, weight, and waist circumference were measured in each participant. At the end of the study, death statistics were correlated with measures of body weight.

The authors found that increasing values for body mass index (BMI), a measure of obesity, were associated with higher death rates in people under 65 years old. This relationship was not seen in people above the age of 65. However, among the older group, increasing waist sizes were associated with higher death rates.

BMI is a ratio of weight to height, defined as the weight in kilograms divided by the square of the height in meters. Most authorities consider a man with a BMI of 27.8 or more to be obese.² For example, an individual who weighs 183 pounds and is 5’8” tall would have a BMI of 27.8. Men under 65 years whose BMI equaled or exceeded that number were 40% more likely to have died during the study, compared to those who had a lower BMI. Men under 65 years with a BMI over 30 (for example, a weight of more than 200 pounds for a 5’8” man) were nearly twice as likely to die during the study compared with people who were not overweight. Higher death rates from both heart disease and cancer were seen in the overweight individuals.

But what about men over age 65? Why did the correlation disappear? According to the authors, it didn’t. Instead, the numbers were confused by the presence of chronic diseases in some of these older people, diseases often associated with weight loss. The fact that expanding waistlines were associated with increasing mortality in those over 65 years supports this line of reasoning.

One question about the validity of this study is whether the outcome was influenced by the fact that the participants were all healthcare professionals. Arguing against that possibility is that the proportion of overweight individuals in this study was similar to that in other published research.³ On the other hand, only 18% of the deaths recorded in this study were attributed to cardiovascular disease, compared to about 40% of deaths in the general adult population,⁴ suggesting that the participants in this study may not be representative of the general population.

Despite the possible limitations of this study, the findings are consistent with those of a large body of research showing that obesity is associated with adverse health consequences. Other studies have reported a similar doubling of death rates at higher BMI levels.^{5 6} Two studies published in the past two months and previously reviewed by Healthnotes Newswire (July 6 and August 24, 2000, editions) point out the importance of maintaining ideal body weight as part of a comprehensive program to reduce cardiovascular disease risk.^{7 8} The available evidence strongly suggests that staying trim increases one’s chances of staying alive.