Obesity could be a greater threat to public health than smoking, a new US study warns.
Researchers from Columbia University and the City College of New York say that while smoking rates are starting to decline, obesity now shortens life-spans in a big way - it causes as much or more disease than tobacco.
The study, conducted over 15 years, was based on interviews with more than 3.5 million people and calculations of the number of "quality-adjusted life years" (QALYs) lost to obesity and smoking.
Quality-adjusted life years are a measurement of the quality and quantity of a life lived, and assign higher scores to perfect or good health, and lower scores to illness, injury and death.
Between 1993 and 2008, smoking in American adults declined by 18.5 per cent, while the proportion of obese people increased by 85 per cent, the study says.
Overall, smoking caused more deaths but obesity has a greater impact on illness, said the researchers.
The study is published in the February issue of the American Journal of Preventive Medicine
Another recent study concluded that if both smoking and obesity rates in the United States remain unchanged, life expectancy in the nation will be reduced by almost nine months. That study was published in the Dec. 3 issue of the New England Journal of Medicine
Back in 2004, the U.S. surgeon general announced that obesity had overtaken tobacco as the No. 1 public health enemy, but now there is more data to support the warning, experts say.
Obesity is a complex disease that can lead to diabetes, liver disease, heart disease, sleep apnea, joint replacement and other problems, noted Dr. Arya Sharma, chairman for obesity research and management at the University of Alberta.
"It hits people at young ages now. We're looking at an epidemic of childhood obesity," said Dr.Sharma. "None of the prevention methods that are being implemented are showing any signs of working. To be effective, they would have to be pretty drastic."