Chances are you have heard news that about 2/3 of the adult U.S. population is overweight or obese.  Ever wonder where this comes from? 

The answer is The National Health and Nutrition Examination Survey (NHANES).  This is a government run study directed by the Centers for Disease Control and Prevention.   The purpose is to monitor the health status of the nation so the data can be used to develop health policies, programs, and services that target the least fit members of the U.S. population. 

In 1996, the Surgeon General’s report on physical activity and health stated that higher cardiorespiratory fitness, which is the body’s ability to use oxygen, decreases overall death rates and morbidity due to chronic diseases. The body’s ability to use oxygen is a strong predictor of many serious health conditions such as heart disease. But where does this statement come from?

While there has been supporting evidence to this statement, such as research from The Cooper Center Longitudinal Study, there has not been any NHANES data until recently. In 1999, a cardiorespiratory fitness component was added to the NHANES study to measure cardiorespiratory fitness using a treadmill test.

On January 15, cardiorespiratory fitness results for 3250 American adults ages 20-49 were published in the American Journal of Epidemiology.1  The results were broken down by age, gender, ethnic group, and body weight category.

Differences in Cardiorespiratory Fitness

Based on Ethnic Group:  No significant difference between White, Black and Mexican American Men     

Based on Gender:

As expected, women had lower cardiorespiratory fitness compared with men.

On average, Black women had significantly lower cardiorespiratory fitness than White and Mexican American women. 

 

Based on Body Weight Category*: Overall, normal weight men had higher cardiorespiratory fitness than overweight or obese men. Within each category of normal, overweight and obese, there were no differences between ethnic groups for men. Normal weight women had no significant differences between ethnic groups. For overweight and obese women there were significant differences as described below. 

* Body weight categories were based on BMI as: Normal weight (BMI 18.5-24.99 kg/m2), Overweight (BMI 25-29.99 kg/m2) and obese (BMI >30 kg/m2).


Overweight and obese Black women had significantly lower cardiorespiratory fitness than their overweight and obese White and Mexican-American counterparts.  As was the case in men, obese women of all ethnic groups had lower cardiorespiratory fitness than their normal weight counterparts.

Cardiorespiratory fitness is a strong predictor of many future health problems such as heart disease and type 2 diabetes. This study is important because it provides the only source of cardiorespiratory fitness data that is based on a national random sample of the U.S. population. Because differences in cardiorespiratory fitness were seen in certain subgroups, the data can be used to develop health policies, programs, and services that target the least fit members of the U.S. population.    

So which category do you fit in and how can you change your data? You have the opportunity to change this data and beat public policy by finding a way to engage in one of the recommended activities from the Stand Up & Eat Active Living Library in hopes of changing this data for the better.

1 CY Wang, WL Haskell, SW Farrell, MJ LaMonte, SN Blair, LR Curtin, JP Hughes, VL Burt. Cardiorespiratory fitness levels among US adults 20-49 years of age: Findings from the 1999-2004 National Health and Nutrition Examination Survey. American Journal of Epidemiology, January 2010.