Overweight and Obesity: Prevalence and Health Risks Dr. David L. Gee FCSN/PE 446

Overweight vs. Obese H Traditional Definitions –Obese: u Body fatness above population norm –Overweight: u Body weight above population norm H Current NIH Definition –Obese is a more severe form of overweight

Body Mass Index H BMI = BW / H 2 H where: –BW = kilograms –H = meters

Body Mass Index H Example: –BW = 165 lbs / 2.2 lbs/kg u = 75 kg –H = 70 in x 2.54 cm/in u = 178 cm = 1.78 m H BMI = 75 / = 24 H BMI is not a direct measure of body fatness

1998 NIH-NHLBI Clinical Guidelines H Expert Panel (24 members) H Systematic Literature Review ( ) H 394 randomized controlled trials H Executive summary 1998 H Arch Int Med (Sept ‘98), JADA (Oct ‘98), NHLBI Web page

1998 NIH-NHLBI Guidelines H Overweight: BMI H Obese: BMI > 30 –Obesity Class I: –Obesity Class II: –Extreme Obesity: >40

Prevalence of Overweight and Obesity in the United States, JAMA 295: (2006) H NHANES All adultsMalesFemales Overweight BMI > 25 66%71%62% Obese BMI > 30 32%31%33% Severely Obese BMI > 40 5%3%7%

Obesity Trends Among U.S. Adults between 1985 and 2005 Source of the data: H CDC’s Behavioral Risk Factor Surveillance System (BRFSS). –state health departments –monthly telephone interviews with U.S. adults. Source of the data: H CDC’s Behavioral Risk Factor Surveillance System (BRFSS). –state health departments –monthly telephone interviews with U.S. adults.

Is being overweight really that dangerous? Excess Deaths Associated with Underweight, Overweight, and Obesity JAMA 2005:293: H “Underweight and obesity… were associated with increased mortality…” H “Overweight was not associated with excess mortality.” H “Study finds government overstated danger of obesity” – USA Today – 4/19/05 – obesity-danger_x.htmhttp:// obesity-danger_x.htm

For adults ages 25-59, increased mortality in underweight and obese categories, but not overweight category.

Is being overweight really that dangerous? Other interpretations: H While risk of mortality may not be greater in overweight subjects, risk of chronic disease is greater in overweight and obese subjects –Improved detection and treatment of risk factors result in reduced mortality in overweight subjects u Hypertension, diabetes, dyslipidemia u Quality of life H Overweight is a temporary state –Most/many overweight become obese –Obese state is clearly a health risk

Prevalence and Trends in Obesity Among US Adults, JAMA 288(14) (2002)

Childhood Obesity

Overweight Prevalence in Children & Adolescents: Definitions H Criteria based on NHANES H Higher BMI criteria –>95th percentile = overweight, medical follow-up (~BMI=30 in adults) –85-95th pct = risk of overweight (~BMI=25 adults)

American children are getting fatter… Prevalence of Overweight* Among U.S. Children and Adolescents (Aged 2 –19 Years) National Health and Nutrition Examination Surveys

American boys of all ethnicities are getting fatter Adolescent Boys Prevalence of Overweight* by Race/Ethnicity (Aged 12–19 Years) National Health and Nutrition Examination Surveys

American girls, especially African- American girls, are getting fatter Adolescent Girls Prevalence of Overweight* by Race/Ethnicity (Aged 12–19 Years) National Health and Nutrition Examination Surveys

The Spread of the Obesity Epidemic in the US, H JAMA 282: (1999) H cross sectional random telephone survey H >100,000 subjects H obesity = BMI > 30 H self-reported data –probable underestimation of obesity

Changes of Obesity Prevalence: Gender Although the prevalence of obesity is higher in women than in men, The rate of increase in obesity is greater in men than in women.

Changes of Obesity Prevalence: Age Although the prevalence of obesity is greater in older Americans, The rate of increase in obesity is rising faster among younger Americans

Changes of Obesity Prevalence: Ethnicity Prevalence of obesity is highest among African-Americans, The rate of obesity rising fastest in the Hispanic population.

Changes of Obesity Prevalence: Education Level Prevalence of obesity is higher in less educated Americans, but The rate of obesity is faster among more educated Americans.

Obesity is growing worldwide Science: 7 January 2005: vol no. 5706, p. 38

Obesity and Health H Contributes to over half of Western chronic diseases. –Coronary heart disease –All major cancers u except lung cancer –Diabetes –Stroke

Obesity and Mortality Rate H Lowest mortality –BMI = –10% to 20% under average BW H Mortality rate increases exponentially above BMI of 25 –CDC 2005 study, above 30

Overweight and Coronary Heart Disease H 70% of CHD cases are overweight H Being overweight –increases CHD mortality risk –increases Total Cholesterol & LDL-C –decreases HDL-C –increases VLDL-TG

BMI and Prevalence of Hypercholesterolemia NHANES III

BMI and Prevalence of Low HDL NHANES III

Obesity and Diabetes Mellitus H 80% of diabetics are overweight H Prevalence –7th most frequent cause of death –11 million cases in US

Diabetes Prevalence 1994 & 2002

Millions of Cases of Diabetes in 2000 and Projections for 2030, with Projected Percent Changes. NEJM 356: (2007)

Obesity and Diabetes Mellitus H Type 1 DM (IDDM) (10-15%) –absolute deficiency of insulin –not associated with obesity H Type 2 DM (NIDDM) (80%) –peripheral insulin resistance –highly associated with overweight –weight loss cornerstone of treatment

Complications of Diabetes H Micro-angiopathies –blindness –renal failure –amputations u uncontrolled infections, numbness H Macro-angiopathies –coronary heart disease

Diagnostic Criteria for Diabetes (2005) H Fasting blood glucose > 126 mg/dl – mg/dl impaired glucose tolerance H Testing for all adults over 45 years every 3 years H Testing earlier or more frequently – if BMI > 25 plus u CVD risk factors u At risk ethnicity u Family history u Chronic inactivity u History of gestational diabetes

Obesity and Stroke H Hypertension and Stroke H Obesity and Hypertension Prevalence –35% of obese have hpt –17% of desirable BMI have hpt H Diagnostic Criteria –systolic BP > 140 or –diastolic BP > 90

BMI and Prevalence of Hypertension

Prevalence of the Metabolic Syndrome Among US Adults JAMA, 287: (2002) H Definition –Cluster of risk factors resulting in substantial increased risk for developing diabetes and cardiovascular disease (NCEP-ATP III) H Criteria: three or more of the following –Abdominal obesity (m>40”, f>35”) –Hypertriglyceridemia (>150mg/dl) –Low HDL-C (m<40mg/dl, f<50mg/dl) –Hi blood pressure (>130/85) –Hi fasting blood glucose (>110 mg/dl)

Prevalence of the Metabolic Syndrome Among US Adults JAMA, 287: (2002) H NHANES III ( ) –8814 adults H Results: –Age adjusted prevalence: 24% –Prevalence increased with age –Prevalence increased in Hispanic-Americans –Prevalence similar in white males & females u Higher in black and Hispanic females than males

Obesity and Cancer H Positive association with: –Breast Cancer (post menopause) –Colon Cancer –Prostate Cancer –Endometrial Cancer H Essentially all except lung cancer

Overweight, Obesity, and Mortality from Cancer in a Prospectively Studied Cohort of U.S. Adults NEJM 348:1625(April 2003) H 900,000 adults –Prospective study, free of cancer u Self reported height/body weight in beginning –16 year follow up –~57,000 cancer deaths

Obesity and Mortality from Cancer NEJM April 2003

Under Fitness vs Over Fatness? H Association of Physical Activity and Body Mass Index With Novel and Traditional Cardiovascular Biomarkers in Women Samia Mora, MD, MHS; I-Min Lee, MBBS, ScD; Julie E. Buring, ScD; Paul M Ridker, MD, MPH JAMA. 2006;295: Samia Mora, MD, MHS; I-Min Lee, MBBS, ScD; Julie E. Buring, ScD; Paul M Ridker, MD, MPH H Women’s Health Study –27,158 healthy women (mean age = 55yrs) –Randomized, placebo controlled for low-dose asprin and vitamin E in primary prevention of CVD and Cancer. –Main outcome measures of this study: u Association of physical activity and BMI on CVD risk factors

Copyright restrictions may apply. Mora, S. et al. JAMA 2006;295: Adjusted Odds Ratios for the Association of Quintiles of Physical Activity and Quintiles of Body Mass Index With Elevated Biomarker Levels* After adjusting for age, race, smoking, systolic blood pressure, diabetes, menopausal status, hormone use, and either BMI or physical activity, both physical activity and BMI remained significantly associated in a linear manner with most biomarker levels, with greater odds ratios (ORs) for BMI compared with physical activity

Copyright restrictions may apply. Mora, S. et al. JAMA 2006;295: Association of Physical Activity and Body Mass Index Categories With Cardiovascular Biomarkers High BMI showed stronger associations with these biomarkers than physical inactivity, but within BMI categories, physical activity was generally associated with more favorable cardiovascular biomarker levels than inactivity.

Association of Physical Activity and Body Mass Index With Novel and Traditional Cardiovascular Biomarkers in Women Samia Mora, MD, MHS; I-Min Lee, MBBS, ScD; Julie E. Buring, ScD; Paul M Ridker, MD, MPH JAMA. 2006;295: Samia Mora, MD, MHS; I-Min Lee, MBBS, ScD; Julie E. Buring, ScD; Paul M Ridker, MD, MPH H Conclusions: H Both lower levels of physical activity and higher levels of BMI were strongly and independently associated with adverse inflammatory and lipid biomarker levels. H BMI showed greater magnitude of association with the biomarkers H A modest level of physical activity was significantly associated with more favorable biomarker profiles, even in overweight or obese individuals. H The most favorable inflammatory and lipid levels were found in women who had at least moderate physical activity levels and were normal weight.

Another view: Cardiorespiratory Fitness, Macronutrient Intake, and the Metabolic Syndrome: The Aerobics Center Longitudinal Study JADA 2006; 106: H ~12,000 adult men and women enrolled in prospective trial at the Cooper Clinic, Dallas, TX H Cross-sectional epidemiological study

Fitness was significantly and inversely associated with prevalent metabolic syndrome in both normal and overweight subjects. (however, researchers did not report absolute risk of normal and overweight subjects)

The Cost of Obesity Health Affairs, Aug 2006 Year% of Medicare Patients with obesity % of Medicare spending on obese patients %9.4% %24.8% $336 billion 2005 total Medicare expenses

Effects of Weight Loss on Health The good news! H Reduces overall mortality H Reduces risk factors –decreases plasma TG –decreases blood pressure –increases HDL-C, decreases LDL-C –decreases fasting blood glucose

The Effect of Weight Loss on Left Ventricular Mass NEJM 314: (1986) 21 week, randomized control trial, n=41, young overweight patients

Hypertension and Weight Loss in Men Conclusion: –modest weight loss results in lowering of blood pressure in obese men. –effect of weight loss is comparable if not better than with medication

Women, Weight Change, & Hypertension H Ann. Internal Med. 128: (1998) H Nurse’s Health Study –1976 – 1992 (16 yr) –82,473 healthy females –16,395 new cases of hypertension

Women, Weight Change, & Hypertension

Long-term effects of modest weight loss in Type II diabetic patients. Arch. Int. Med. 147: (1987) 1 year, Behavioral weight control program, N=114 type 2 diabetics

Long-term effects of modest weight loss in Type II diabetic patients. H Conclusions: –Modest weight loss results in u improved glucose control u improved insulin sensitivity u reduced triglycerides u increased HDL-C

Prevention of Type 2 Diabetes Mellitus by Changes in Lifestyle among Subjects with Impaired Glucose Tolerance H NEJM - May 2001 H 522 middle age males –BMI = 31 –w/ impaired glucose tolerance H 3.2 year follow-up –Intervention group u individualized wt. loss counseling –Control group u standard advice

Prevention of Type 2 Diabetes Mellitus by Changes in Lifestyle among Subjects with Impaired Glucose Tolerance H Weight Loss –Intervention = 4.2 kg –Control = 0.8 kg H Diabetes 3 years –Intervention = 11% –Control = 23% H “The reduction in the incidence of diabetes was directly associated with changes in lifestyle”

Weight Cycling - Risk Factor? H Significant and deliberate fluctuations in body weight –Yo-yo dieting H Framingham Studies (1991) –individuals with greatest weight fluctuations had highest risk of overall mortality and mortality & morbidity to coronary heart disease.

Variability of body weight and health outcomes in the Framingham population. NEJM 324: (1991)

Weight Cycling and Cholecystectomy in Women H Ann. Internal Med. (Mar 1999) H Nurse’s Health Study –(47,153 women, 30-55yr, w/o gall bladder disease, ) H Weight cycling history (1 episode intentional) –light = 5-9 lbs (20.1% of subjects) –moderate = lbs (18.8%) –severe = >20 lbs (16%)

Weight Cycling and Cholecystectomy in Women H Adjusted relative risk for cholecystectomy compared to women who maintained their weight: –1.20 for light cyclers –1.31 for moderate cyclers –1.68 for severe cyclers H Caused by: –weight cycling? –severity of obesity?

Intentional vs Unintentional Weight Loss and Mortality in Older Women. H Iowa Women’s Health Study –25,897 women (55-69 yrs) –questionnaire regarding wt loss since 18 yrs old –followed 4 years

Intentional vs Unintentional Weight Loss and Mortality in Older Women. H Intentional wt loss (> 20 lbs): –risk of total or CHD mortality not affected H Unintentional wt loss: –26-57% greater mortality risk, –51-114% greater CHD risk H Increased mortality due to wt loss due to pre-existing disease.

Weight Cycling: Health Risk Factor? H NIH/NIDDK/WIN statements H risk of remaining obese vs. risk(?) of weight cycling H underscores importance of life- long changes in behaviors to attain a healthy weight.

A Prospective Study of Weight Change and Health-Related Quality of Life in Women H JAMA Dec H Nurse’s Health Study –40,098 women, 4 yr longitudinal study –Weight changes –Quality of life questionnaire u Physical function u Vitality u Freedom from bodily pain u Mental health

The effect of weight gain/loss on: Vitality Score H Weight gain: –associated with declines in vitality scores in all BMI categories H Weight loss –associated with improved vitality scores only in women with BMI>25

The effect of weight gain/loss on: Mental Health Score H Weight gain –associated with a decline in mental health scores in all weight categories H Weight loss –associated with improved mental health scores only in obese class I women and declined in normal weight women.

A Prospective Study of Weight Change and Health-Related Quality of Life in Women. Conclusions: H For women at all BMI categories: –Don’t gain weight –Reduced quality of life H For overweight and obese women: –Weight loss is generally associated with improved quality of life H For normal weight women –Weight loss does not improve quality of life u May actually reduce quality of life

H Lose weight to improve health –Optimal health attained at BMI = 18,5-25 H Avoid trying to lose weight to look like a media star –Media stars often may u Be genetically thin u Lose weight in unhealthy ways u Actually not be all that thin

Jamie Lee Curtis Before and after work with 13 experts & 3 hours “True Thighs” More magazine, August 2002

"The retouching is excessive. I do not look like that and more importantly I don't desire to look like that," she said. "I actually have a Polaroid that the photographer gave me on the day of the shoot… I can tell you they've reduced the size of my legs by about a third. For my money it looks pretty good the way it was taken."