Severely obese are fastest growing group of overweight Americans, study finds

October 1, 2012

The proportion of Americans who are severely obese—those people 100 pounds or more overweight—continues to increase rapidly and much faster than those with moderate obesity, but the rate of growth has slowed, according to a new RAND Corporation study.

The RAND study found that from 2000 to 2010, the proportion of Americans who were severely obese rose from 3.9 percent of the population to 6.6 percent—an increase of about 70 percent.

The findings mean that more than 15 million adult Americans are morbidly obese with a body mass index of 40 or more. The good news is that beginning in 2005, the near- of the severely obese group began to flatten out.

"The proportion of people at the high end of the weight scale continues to increase faster than any other group of obese people, despite increased on the risks of obesity," said Roland Sturm, lead author of the report and a senior economist at RAND, a nonprofit research organization. "But for the first time in the past 20 years there is evidence the trend is slowing."

The study suggests that clinically severe obesity, instead of being a rare pathological condition among genetically vulnerable individuals, is an integral part of the population's weight distribution. As the whole population becomes heavier, the extreme category—the severely obese—increases the fastest.

The findings were published online by the .

The trend of severe obesity varies by gender and ethnicity, although the trend remained upward among all groups. The prevalence of severe obesity was about 50 percent higher among women than among men, and about twice as high among blacks when compared to or whites. For all levels of obesity, the increases over time were faster among younger than 40.

To be classified as severely obese, a person must have a body mass index (a ratio of weight to height) of 40 or higher—roughly 100 pounds or more for an average adult man. The typical severely obese man weighs 300 pounds at a height of 5 feet 10 inches tall, while the typical severely obese woman weighs 250 pounds at a height of 5 feet 4 inches.

People with a BMI of 25 to 29 are considered overweight, while a BMI of 30 or more classifies a person as being obese. For a 5-foot-10 inch male, a BMI of 30 translates into being 35 pounds too heavy.

The body mass index allows researchers to define obesity and severe obesity over a population of people with varied heights and weights. The index is defined as weight in kilograms divided by the square of height in meters. The standard cut-off point for obesity is a of 30 or more, corresponding to a person 5 feet 4 inches tall and weighing 174 pounds, or 5 feet 10 inches tall and weighing 209 pounds or more.

Explore further: ECO: Behavioral treatment for obesity effective in children

Related Stories

ECO: Behavioral treatment for obesity effective in children

May 14, 2012
(HealthDay) -- Behavioral treatment for obesity is much more effective for younger children than for adolescents, according to a study presented at the European Congress on Obesity, held from May 9 to 11 in Lyon, France.

Teen weight began to rise in 1990s, new study finds

July 12, 2011
A new study that looks at weight change over decades finds that the obesity epidemic in teens and young adults has its roots in the late 1990s and early 2000s, when body weights began to rise. But not everyone was affected ...

Recommended for you

Shaming overweight kids only makes things worse

November 20, 2017
(HealthDay)—Overweight kids who are shamed or stigmatized are more likely to binge eat or isolate themselves than to make positive changes such as losing weight, a leading pediatricians' group says.

Link between obesity and cancer is not widely recognized

November 17, 2017
A new study published in the Journal of Public Health has shown that the majority of people in the United Kingdom do not understand the connection between weight issues and cancer. Obesity is associated with thirteen types ...

Reversing negative effects of maternal obesity

November 8, 2017
A drug that increases energy metabolism may lead to a new approach to prevent obesity in children born to overweight mothers, UNSW Sydney researchers have found.

Serving water with school lunches could prevent child, adult obesity: study

November 7, 2017
Encouraging children to drink plain water with their school lunches could prevent more than half a million youths in the U.S. from becoming overweight or obese, and trim the medical costs and indirect societal costs associated ...

Why do some obese people have 'healthier' fat tissue than others?

November 1, 2017
One little understood paradox in the study of obesity is that overweight people who break down fat at a high rate are less healthy than peers who store their fat more effectively.

Engineered protein treatment found to reduce obesity in mice, rats and primates

October 19, 2017
(Medical Xpress)—A team of researchers with pharmaceutical company Amgen Inc. report that an engineered version of a protein naturally found in the body caused test mice, rats and cynomolgus monkeys to lose weight. In their ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.