In the December 2012 issue of Discover, Dr. Linda Bacon provides a commentary which supports the HAES approach to healthy active living. Dr. Bacon cites data from the CDC (published in the Journal of the American Medical Association in 2005 and an independent report in 2011 - not referenced) which shows that people classified as overweight live longer than normal weight people, and that despite the increases in obesity in the US between 1970 and 2007, life expectancy has increased from 70.8 to 77.9 years.
The claims that overweight people live longer than normal weight people, and that life expectancy has increased alongside obesity are important to recognize - indeed, overweight is associated with longevity in many other species in the animal kingdom, and there are metabolically healthy obese individuals.
While all of this true, Dr. Bacon does not mention the effects of overweight and obesity on morbidity or quality of life. A paper published by the American Journal of Preventative Medicine in 2010 suggests that quality-adjusted life years lost due to obesity doubled from 1993 to 2008. Overweight and mildly obese people may be expected to live longer than their normal weight counterparts, but time and time again the research literature has shown that obesity is associated with a number of chronic diseases. Chronic diseases have a tendency to reduce an individual's quality of life.
A meta-analysis published last week in the Journal of the American Medical Association provides a similar conclusion- while grades 2 and 3 obesity (BMI= 35-40, and 40+) are associated with an increase in all-cause mortality (basically, death from everything), grade 1 obesity (BMI=30-35) was no different than normal weight, and overweight (BMI= 25-30) was associated with lower all-cause mortality. The authors note in their discussion a major limitation of this meta-analysis - not evaluating weight status according to a measure of morbidity.
As we continue to conduct research in this area it is important to remember that life expectancy is not the only measure of health. There is much more to both health, and obesity, than meets the eye.