A new study by the US Centers for Disease Control and Prevention (CDC) released yesterday, 28th November, said that the rate of obesity among adults aged 20 and over in the US appears to be levelling off, and maybe even going down slightly in women, but at around 34 per cent of the adult population, it is still still too high.

Titled “Obesity Among Adults in the United States; No Change Since 2003-2004,” the study is based on the National Health and Nutrition Examination Surveys, carried out by CDC’s National Center for Health Statistics.

The study shows that rates of obesity have gone up steadily over the last 25 years, but the figures for 2003-04 and 2005-06 show a levelling for both men and women.

For men, there has been a steady rise in obesity rates between 1999 and 2006, but for women, since 1999 there appears to be a levelling off. The gap that used to exist between male and female obesity rates (more obesity among women) has gradually closed, with the effect looking as though men have caught up with women, said lead author of the study, Cynthia Ogden, who is a researcher with the CDC.

A person is said to be obese if their Body Mass Index (BMI, ratio of weight in kilos to height in metres, squared) is 30 or more. Obesity is a recognized major risk factor for a range of health problems, many of them serious, such as cardiovascular disease, some cancers, and type 2 diabetes.

The main results of the study were:

  • Over 72 million American adults (more than one third of US adults) were obese in 2005-06.
  • This figure includes 33.3 per cent of men and 35.3 per cent of women.
  • There was no statistically significant change between the 2005-06 figures and the 2003-04 figures.
  • In 2003-04 31.1 per cent of men and 33.2 per cent of women were obese.
  • Compared with other age groups, 40-59 had the highest proportion of obese adults.
  • About 40 per cent of men in the 40-59 age group were obese.
  • This compared with 28 per cent in the 20-39 age group, and 32 per cent in the 60 and above group.
  • Among women, about 41 per cent in the 40-59 age group were obese.
  • this compared with 30.5 per cent in the 20-39 age group, which was about the same in the 60 and over group.

There were considerable disparities in female obesity rates among race and ethnic groups. About 53 per cent of non-Hispanic black women and 51 per cent of Mexican-American women aged 40-59 were obese. This compared with about 39 percent of non-Hispanic white women in the same age group.

In the 60 and older group, 61 per cent of non-Hispanic black women were obese compared with 37 per cent of Mexican-American women and 32 per cent of non-Hispanic white women.

The results showed no disparities in male obesity rates among race and ethnic groups.

The study also said that about one third of obese adults had not been informed by their health care practitioner that they were overweight, a figure that has not changed over recent years said Ogden.

Director of CDC’s National Center for Chronic Disease Prevention and Health Promotion, Janet Collins said that:

“In view of these alarmingly high rates of obesity in all population groups, CDC has made the prevention of obesity one of its top public health priorities.”

“We are actively working in partnership with state and local public health agencies, the Nation’s schools, community organizations, businesses, medical systems, and faith communities to promote and support healthy eating, physical activity, and healthy weight,” she added.

“Obesity Among Adults in the United States – No Change Since 2003�”2004.”
Cynthia L. Ogden, Margaret D. Carroll,Margaret A. McDowell, and Katherine M. Flegal, Division of Health and Nutrition Examination Surveys.
NHCS Data Brief no 1, November 2007, Hyattsville, MD: National Center for Health Statistics.

Click here for the full report (PDF).

Written by: Catharine Paddock