Obesity in the U.S.Prevalence and Trends

Pennington Biomedical Research CenterDivision of Education

Publication # 23

Obesity in the U.S.Current Trends

Currently, about 66% of American adults are overweight and about 32% are obese.

The obesity weight class has increased the most over the past few decades.

Compared with prevalence rates reported in 1976-80, the rates of obesity seen today are more than double what they were only thirty years ago.

Overweight is Rising

50

52

54

56

58

60

62

64

66

68

1988-94 1999-2000 2001-02 2003-04

Prevalence of overweight andobesity among U.S. adults 20years of age and older

This overweight classification combines those who are classified as overweight (BMI 25-29.9) and those who are obese (BMI ≥ 30).

56.0

64.565.7 66.3

Adapted from: the Centers for Disease Control and Prevention (CDC)

1996

1991

No Data <10% 10%–14% 15%–19% 20%–24% ≥25%

2004

Obesity Continues to Rise

Source: Behavioral Risk Factor Surveillance System, CDC

Obesity is defined as having a BMI ≥ 30

Trends in the United States

Prevalence of obesity by state

Obesity An estimated 66 million adults in the United States are obese.

Being either overweight or obese substantially raises one’s risk of morbidity from: Hypertension Dyslipidemia Type 2 diabetes Coronary heart disease Stroke Gallbladder disease Osteoarthritis Sleep apnea and respiratory problems Endometrial, breast, prostate, and colon cancers.

ObesityIntroduction

In addition to the increased risk for several diseases, higher body weights are also associated with increases in all-cause mortality.

An estimated 300,000 deaths per year are attributable to obesity.

As the second leading cause of preventable death in the United States today, overweight and obesity pose a major public health threat.

Obesity in the U.S.Race/Ethnic

The picture is even worse when rates are looked at by gender and ethnic backgrounds: 77 percent of Black women are overweight, and 50 percent are obese, while 72 percent of Mexican-American women are overweight, and 40 percent of

Mexican American women are obese.

Significant differences in obesity exist among different racial or ethnic groups

CDC/NCHS; Flegal KM 2002

Obesity in the U.S.Socioeconomic Status

A Dutch study found a link between socioeconomic status (SES) and obesity. In fact, those in the very low SES had the highest rates of obesity

and consumed the most soft drinks, potatoes, fat, and meat.

A long term study found that African American women had higher rates of obesity than Caucasian regardless of SES.

Hulshof KFAM et al. 2003; Zhang and Wang 2004; Johnson-Down et al 1997

Obesity in the U.S.Socioeconomic Status

Higher socioeconomic group women: Diet more often Have greater access to resources Have better nutrition knowledge Are committed to slimness Avoid high fat foods Get more physical activity

In Developing CountriesObesity & SES

Higher socioeconomic group women: Have more incidence of obesity Have less malnutrition Have less infection Have a steady source of income and food

In fact, overweight is associated with wealth

Obesity in the U.S.What is the Cost?

According to a study of national costs attributed to both overweight and obesity, medical expenses accounted for 9.1% of the total U.S. medical expenditures in 1998.

Medical expenses for overweight and obesity may have reached as high as $78.5 billion in 1998.

In Louisiana alone, approximately $1.4 billion was spent on overweight and obesity-related medical expenses.

ObesityWhat are the Causes?

Overweight and obesity are the result of an energy imbalance over a long period of time.

While the whole picture is still unclear on how obesity develops, it is believed to involve the integration of social, behavioral, cultural, physiological, metabolic, and genetic factors.

Behavior and environment appear to play a large role the development of obesity, and are often the focus for prevention and treatment actions.

Energy ImbalanceWhat is it?

Energy balance is like a scale where both sides are of equal weight.

An energy imbalance arises when the number of calories consumed is not equal to the number of calories used by the body.

Weight gain usually involves the combination of consuming too many calories and not expending enough enough through physical activity, although weight gain could result from one or the other.

Weight Gain

Calories Consumed > Calories Used

Weight Loss

Calories Consumed < Calories Used

No Weight Change

Calories Consumed = Calories Used

CDC

ObesityDiet and Exercise

Physical activity contributes to weight loss, especially when combined with a calorie reduction.

Physical activity is important in preventing overweight and obesity and in maintaining weight that is lost.

In addition to weight control, physical activity helps: Prevent heart disease Control cholesterol levels and diabetes To slow bone loss associated with advancing age Lower the risk of certain cancers Reduce anxiety and depression

Body Mass IndexIndicator of Weight Status

Body mass index (BMI) is a mathematical ratio taking into account an individual’s weight, in kilograms, and height, in meters squared (kg/m2). This measure can be used for adults 20 years of age and older.

BMI determines an individuals weight category.

With a BMI of: You are considered:

Below 18.5 Underweight

18.5 - 24.9 Healthy Weight

25.0 - 29.9 Overweight

30 or higher Obese

You can find tables on the web that that are ready-made for you. http://www.nhlbisupport.com/bmi

Obesity Classes

Class 1 BMI of 30-35

Class 2 BMI of 35-40

Class 3, Extreme obesity BMI greater than 40

Waist Circumference

Waist circumference is a predictor of mortality and chronic disease. It is a prognostic indicator along with BMI. The presence of excess body fat in the abdomen, when out of

proportion to total body fat, is considered an independent predictor of risk factors and ailments associated with obesity.

Men = Greater than 40 inches Women = Greater than 35 inches

Waist Circumference & BMIAnd Disease Risk

BMI (kg/m2) Obesity Class Men ≤ 102 cm (≤ 40 in)Women ≤ 88 cm (≤ 35 in)

> 102 cm (> 40 in)> 88 cm (>35 in)

Underweight < 18.5 ----- -----

Normal 18.5 – 24.9 ----- -----

Overweight 25.0 – 29.9 Increased High

Obesity 30.0 – 34.9 35.0 – 39.9

III

HighVery High

Very HighVery High

Extreme Obesity ≥ 40 III Extremely High Extremely High

Disease Risk * Relative to Normal Weight and Waist Circumference

* Disease risk for type 2 diabetes, hypertension, and cardiovascular disease

Adapted from: Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults

Why is a BMI of 20-25 considered as a

reference weight?

0

0.5

1

1.5

2

2.5

19 20 25 35

Risk

Increased risk

Body Mass Index

This is because the relationship between morbidity and mortality and BMI is minimal at that range.

Body Mass Index

It is important to remember that although BMI correlates with the amount of body fat a person has, it does not directly measure body fat.

However, with the exception of highly trained athletes, BMI is a good predictor of chronic disease and mortality in individuals.

In Summary…

The prevalence of overweight and obesity in the U.S. is higher than ever before. BMI & waist circumference are correlated with body fat and can predict the risk for disease. Being overweight or obese substantially raises one’s risk of morbidity from many diseases. Significant differences exist in obesity among different racial or ethnic groups. Diet and physical activity are important in the fight against obesity.

Pennington Biomedical Research Center

Division of Education

Heli J. Roy, PhD, RD, Associate Professor

Shanna Lundy, BS Beth Kalicki Division of Education

Phillip Brantley, PhD, DirectorPennington Biomedical Research CenterClaude Bouchard, PhD, Executive Director

Edited: October 2009

About Our Company

The Pennington Biomedical Research Center is a world-renowned nutrition research center.   Mission: To promote healthier lives through research and education in nutrition and preventive medicine.   The Pennington Center has several research areas, including:   Clinical Obesity Research Experimental Obesity Functional Foods Health and Performance Enhancement Nutrition and Chronic Diseases Nutrition and the Brain Dementia, Alzheimer’s and healthy aging Diet, exercise, weight loss and weight loss maintenance   The research fostered in these areas can have a profound impact on healthy living and on the prevention of common chronic diseases,

such as heart disease, cancer, diabetes, hypertension and osteoporosis.   The Division of Education provides education and information to the scientific community and the public about research findings, training

programs and research areas, and coordinates educational events for the public on various health issues.   We invite people of all ages and backgrounds to participate in the exciting research studies being conducted at the Pennington  Center in

Baton Rouge, Louisiana. If you would like to take part, visit the clinical trials web page at www.pbrc.edu or call (225) 763-3000.

Additional Resources: MyPyramid: Food Pyramid. Available at: http://www.mypyramid.gov Overweight and Obesity: Contributing Factors. Available at:

http://www.cdc.gov/nccdphp/dnpa/obesity/contributing_factors.htm Calculate your daily calorie needs. Available at:

http://www.cancer.org/docroot/PED/content/PED_6_1x_Calorie_Calculator.asp How many calories will your activity burn? Available at:

http://www.cancer.org/docroot/PED/content/PED_6_1x_Exercise_Counts.asp?sitearea=&level

References Centers for Disease Control and Prevention. Available at: http://www.cdc.gov Clinical guidelines on the identification, evaluation, and treatment of overweight and

obesity in adults. Available at: http://www.nhlbi.nih.gov/guidelines/obesity/ob_exsum.pdf Obesity trends among U.S. adults. Available at:

http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/obesity_trends_2004.ppt Johnson-Down L, O'Loughlin L, Koski KG, and Gray-Donald K. High Prevalence of

Obesity in Low Income and Multiethnic Schoolchildren: A Diet and Physical Activity Assessment. The Journal of Nutrition Vol. 127 No. 12 December 1997, pp. 2310-2315.

References Legal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity

among US adults, 1999-2000 JAMA. 2002;288:1723-1727. Zhang, Q and Wang Y. Trends in the association between obesity and socioeconomic

status in US Adults: 1971-2000. Obesity Research 12:1622-1632, 2004. Hulshof KF, Brussaard JH, Kruizinga AG, Telman J, Lowik MR. Socio-economic

status, dietary intake and 10 y trends: the Dutch National Food Consumption Survey. Eur J Clin Nutr. 2003 Jan;57(1):128-37.