Washington, Feb 1 : Two experts have challenged skeptics who say that the obesity epidemic is not as grave or widespread as we think.
Two prominent skeptics have been confronted by two obesity experts from the University of Minnesota in a heated debate in the British Medical Journal.
Patrick Basham, a lecturer at Johns Hopkins University, and John Luik, both health policy experts, argue that claims about an obesity epidemic often exceed the scientific evidence and mistakenly suggest an unjustified degree of certainty.
But Robert Jeffery, a professor at the University of Minnesota, and Nancy Sherwood, a researcher at HealthPartners, say that the skeptics are simply denying the obvious.
Pointing to increased life expectancy and reductions in heart disease in recent years, Basham and Luik, coauthors of "Diet Nation: Exposing the Obesity Crusade," say scientists haven't proved that obesity carries major health risks.
Furthermore, they say, that the categories of normal, overweight, and obese is entirely arbitrary and at odds with the underlying evidence about the association between body mass index and mortality.
They suggest that some public health professionals may have deliberately exaggerated the risks of overweight and obesity, and our capacity to prevent or treat them on a population wide basis, in the interests of health. They warn that this has unwelcome implications for science policy and for evidence based medicine.
But Jeffery and Sherwood argue that a large body of scientific evidence shows that obesity is a major global health problem.
In the US, the prevalence of obesity in 1976-80 was 6.5 percent among 6-11 year olds and 5 percent among 12-17 year olds. In 2003-4 it was 19 percent and 17 percent respectively. Europe can also expect to see the numbers of overweight and obese children rising by around 1.3 million a year by 2010.
The risks of obesity on many serious health conditions including high blood pressure, diabetes, heart disease and some forms of cancer, are also serious and well established, Jeffery and Sherwood argue.
Most health economists and epidemiologists agree that the contribution of obesity to current healthcare costs is high and that it is likely to get much higher. Some have argued that we may even see real falls in life expectancy within a few decades, they add.
To sum up, a large body of evidence documents that over-nutrition and obesity are a major global health problem, say the authors.