Obesity is still rising among Americans, according to figures from the US Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System, where data based on annual nationwide telephone surveys with more than 350,000 adults showed that between 2005 and 2007, the percentage who reported being obese went up from 23.9 to 25.6, a rise of nearly 2 per cent.

The full report is published in this week’s Morbidity and Mortality Weekly Report (MMWR), available as a download from the CDC website.

Obesity is defined in terms of BMI, Body Mass Index, the ratio of a person’s weight to the square of their height (calculated in kilos and metres). So, a person whose weight is 92 kilos (203 pounds) and height is 1.75 m (5 feet 9 inches), has a BMI of 30, which puts them in the obese category (the category below this, BMI from 25 to 30, is classed as overweight, with desirable or healthy BMI being in the 20 to 25 range).

Studies show that obesity is linked to reduced quality of life and premature death, as well as chronic illnesses like heart disease and diabetes.

The report found that none of the 50 states, or the District of Columbia, attained the Healthy People 2010 goal, which is for a state’s maximum proportion of obese adults to be 15 per cent or less. The state with the lowest rate of obesity was Colorado, with 18.7 per cent of adults self-reporting as being obese, and the highest prevalence was in Alabama, Mississippi, and Tennessee, with self-reported obesity rates reaching over 30 per cent of the adult population.

Under the Behavioral Risk Factor Surveillance System, the agency carries out an annual, nationwide survey that interviews over 350,000 adults aged 18 and over on the telephone. This is the largest telephone health survey in the world. The BMI figures were calculated from the respondents’ answers to questions about their height and weight.

Director of CDC’s Division of Nutrition, Physical Activity, and Obesity, Dr William Dietz, said:

“The epidemic of adult obesity continues to rise in the United States indicating that we need to step up our efforts at the national, state and local levels.”

“We need to encourage people to eat more fruits and vegetables, engage in more physical activity and reduce the consumption of high calorie foods and sugar sweetened beverages in order to maintain a healthy weight,” he added.

The survey showed that obesity rates are higher in the Southern states, where 27 per cent of those interviewed fell into the obese category. In the Midwest, Northeast and West, the obesity rates were 25.3, 23.3 and 22.1 per cent respectively.

Looking at the 2007 figures by age, obesity rates ranged from 19.1 per cent for men and women in the 19 to 29 age group, up to 31.7 per cent for men and 30.2 per cent for women aged 50 to 59.

Broken down by race/ethnicity, the 2007 figures show that the highest obesity rate was among Black non Hispanics, at 35.8 per cent, followed by Hispanic at 28.5 per cent and White, non Hispanic at 24.5 per cent. Within these figures, by gender, the figure that stands out is the 39.0 per cent obesity prevalence among Black, non Hispanic women, which contrasts with 28.8 and 22.9 per cent among Hispanic and White non Hispanic women respectively.

Examined by education level, the lowest obesity rate among men and women was among female college graduates, with a 17.9 per cent obesity rate, compared with the highest rate of 32.6 per cent, which was among females with less than a high school diploma.

Associate director for science for CDC′s Division of Nutrition, Physical Activity and Obesity, Deb Galuska said:

“Obesity is a major risk factor for a number of chronic diseases such as type 2 diabetes, heart disease and stroke. These diseases can be very costly for states and the country as a whole.”

“State-Specific Prevalence of Obesity Among Adults — United States, 2007.”
US Centers for Disease Control and Prevention (CDC).
MMWR, Morbidity and Mortality Weekly Report, July 18, 2008 / Vol. 57 / No. 28 / pp 765-768.

Click here to donwload full MMWR report (PDF).

Sources: CDC.

Written by: Catharine Paddock, PhD