Number of severely obese people increasing

"The proportion of people at the high end of the weight scale continues to increase at a brisk rate despite increased public attention on the risks of obesity and the increased use of drastic weight loss strategies such as bariatric surgery," said study author Roland Sturm, a Rand Corp. research organization economist.

To be classified severely obese, a person must have a body mass index of 40 or higher. The typical severely obese man weighs 300 pounds at a height of 5 feet 10 inches, while the typical severely obese woman weighs 250 pounds at a height of 5 feet 4 inches.

Sturm found between 2000 and 2005 the proportion of Americans with a BMI of 50 or more increased by 75 percent, compared with 24 percent among people with a BMI of 30 or more and 40 percent among those with a BMI of 40 or more. The heaviest groups have been increasing at the fastest rates for the past 20 years.

The report is to appear later this year in the journal Public Health.

Copyright 2007 by United Press International