Published on August 9, 2007
Obesity in the U.S.Prevalence and Trends: Obesity in the U.S. Prevalence and Trends Pennington Biomedical Research Center Division of Education Obesity in the U.S.Current Trends: 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: Overweight is Rising This overweight classification combines those who are classified as overweight (BMI 25-29.9) and those who are obese (BMI ≥ 30). 56.0 64.5 65.7 66.3 Adapted from: the Centers for Disease Control and Prevention (CDC) Obesity Continues to Rise: 1996 No Data andlt;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: 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: Obesity Introduction 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: 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: 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: 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: In Developing Countries Obesity andamp; 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?: 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?: Obesity What 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 Imbalance What 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 andgt; Calories Used Weight Loss Calories Consumed andlt; Calories Used No Weight Change Calories Consumed = Calories Used CDC ObesityDiet and Exercise: Obesity Diet 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 Indicator 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. You can find tables on the web that that are ready-made for you. http://www.nhlbisupport.com/bmi Obesity Classes: 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 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: Waist Circumference andamp; BMI And Disease Risk 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?: Why is a BMI of 20-25 considered as a reference weight? Increased risk Body Mass Index This is because the relationship between morbidity and mortality and BMI is minimal at that range. Body Mass Index: 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…: In Summary… The prevalence of overweight and obesity in the U.S. is higher than ever before. BMI andamp; 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: Pennington Biomedical Research Center Division of Education Phillip Brantley, PhD, Director Heli J. Roy, PhD, RD, Associate Professor Shanna Lundy, BS Additional Resources:: 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=andamp;level References: 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: 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.