Underweight and overweight both linked with increased mortality

Reported by Susan Aldridge, PhD, medical journalist

Compared to those who are normal weight, people who are obese or underweight have an increased death rate.
As obesity increases, there is concern over whether this might have an impact on mortality, given its numerous health hazards. A group at the Centers for Disease Control and Prevention in the USA now report on a study that looks at the association between weight and mortality.

This was part of the National Health and Nutrition Examination Surveys (NHANES) and shows how, relative to normal weight (body mass index 18.5 to less than 25) obesity (BMI of 30 or more) was linked to an increased death rate, as was underweight. But overweight (BMI between 25 and 30) was not linked to increased mortality.

The researchers believe that the link between obesity and mortality may have decreased with time, maybe because of improvements in public health or medical care for obesity-related conditions. In other words, the overweight may be healthier than they used to be. However, obesity and overweight are still risky - so people should do their best to keep to a healthy weight.

Source
Journal of the American Medical Association 20th April 2005 Volume 293 pages 1868-1874