Assessment of the Obesity Epidemic
More than 60% of US Adults Are Overweight Obese (BMI ≥ 30) Overweight (BMI 25 - 29.9) Flegal K, et al. JAMA 2002;288:1723-1727. Hedley AA, et al. JAMA 2004;291:2847-2850.
Assessing Obesity: What Is BMI? Calculated as weight(kg)/height(m2) Evaluates weight relative to height Replaced % ideal body weight as the primary criterion for assessing obesity Correlates significantly with body fat, morbidity, and mortality Category BMI Underweight < 18.5 Normal* 18.5 – 24.9 Overweight 25.0 – 29.9 Obesity ≥ 30.0 Class I 30.0 – 34.9 Class II 35.0 – 39.9 Class III ≥ 40.0 The BMI, easily calculated by office staff, should be an essential part of the patient work-up BMI Is calculated as weight divided by height squared Evaluates weight relative to height Has replaced % ideal body weight as the primary criterion for assessing obesity Correlates significantly with % of total body fat, morbidity, and mortality Conversion tables are available so calculations are done for you Today, calculating the BMI in all patients is considered to be state-of-the-art medicine Today, there are successful, proven approaches for controlling obesity Knowing the BMI is the first step to categorizing the patient’s overweight and obese status Repeated calculations lead to understanding the patient’s trends for risks associated with obesity Waist circumference is an additional measure of the level of risk associated with obesity Classification for BMI - see file 1 NIH Natl Heart, Lung, and Blood Inst. Obes Res. 1998;6(suppl 2):51S. Willett WC et al. N Engl J Med. 1999;341:427.
Prevalence of Obesity by Age Men Women Flegal et al. JAMA 2002;288:1723-1727.
Obesity Trends by Gender and Ethnicity Men Women Flegal K, et al. JAMA 2002;288:1723-1727.
Prevalence of Obesity by Education and Income 23.00 23.50 24.00 24.50 25.00 25.50 26.00 26.50 27.00 27.50 Average BMI 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year Lowest Highest Average BMI 22 23 24 25 26 27 28 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year No High School High School Some College College Flegal et al. JAMA 2002;288:1723-1727.
Prevalence of Extreme Obesity (BMI ≥ 40) by Gender and Ethnicity Men Women Hedley AA, et al. JAMA 2004;291:2847-2850.
Prevalence of Overweight in Children and Adolescents Flegal K, et al. JAMA 2002;288:1723-1727. Hedley AA, et al. JAMA 2004;291:2847-2850.
Obesity and Coronary Heart Disease (CHD) Morbidity mortality Morbidity mortality Morbidity mortality Hypertension Diabetes Dyslipidemia 40% are obese 80% are obese 50% – 70% are obese OBESITY
Trends in Cardiovascular Risk Factors in Obese Individuals (BMI ≥ 30 kg/m2 ) High Blood Pressure Smoking High Cholesterol Diabetes Gregg EW, et al. JAMA 2005;293:1868-1874.
Obesity Is Caused by Long-Term Positive Energy Balance Fat stores Energy expenditure Energy intake
Regulation of Body Weight Genes confer the potential for obesity Environment determines whether and to what extent the potential is realized
Weight Classification of Adoptees Relationship Between Adoptee Weight and Weight of Biological or Adoptive Parents 27 21 26 25 24 23 22 Biological Parents Adoptive Parents BMI of Parents (kg/m2) Fathers Mothers Thin Median Overweight Obese Thin Median Overweight Obese Weight Classification of Adoptees Stunkard et al. N Engl J Med 1986;314:193.
Heritability of Body Weight
Components of Daily Energy Expenditure Thermic effect of feeding Resting energy expenditure Energy expenditure of physical activity 8% 17% 8% 32% 75% 60% Sedentary person (1800 kcal/d) Physically active person (2200 kcal/d)
Decreased Energy Expenditures and Weight Gain Low RMR Middle RMR High RMR 1 2 3 4 5 10 15 20 25 30 Cumulative Incidence of a 10-kg Body Weigh Gain (%) Time (years) RMR = resting metabolic rate Ravussin E, et al. N Engl J Med. 1988;318:467-472.
Barsh GS, Schwartz MW. Nat Rev Genet. 2002;3:589-600.
Gene-Environment Interaction in the Pathogenesis of Obesity Body Mass Index (kg/m2) 10 20 30 40 50 p < 0.0001 Pima Indians in Maycoba, Mexico Pima Indians in Arizona Ravussin E et. al. Diabetes Care 17:1067, 1994.
The Toxic Environment Food is… Highly accessible Inexpensive Advertised heavily High fat, high sugar Delicious
16 oz 32 oz 44 oz 52 oz 64 oz 1 oz ≈ 12 calories
Food Portion Size Trends 5 10 15 20 Salty Snacks Desserts Soft Drinks Fruit French Fries Ham- burgers Cheese-burgers Pizza Mexican Food Food Intake per Eating Occasion, oz 1977-1978 1989-1991 1994-1998 Nielsen & Popkin, JAMA 2003.
Prevalence of Obesity by Hours of TV per Day NHES Youth Aged 12 to 17 in 1967-1970 and NLSY Youth Aged 10 to 15 in 1990 5 10 15 20 25 30 35 40 TV hours per day (youth report) Prevalence (%) NHES 1967-1970 NLSY 1990 0 - 1 1 - 2 2 - 3 3 - 4 4 - 5 > 5
Daily Physical Education % of Children with Daily Physical Education American Academy of Pediatrics.
Responding To The Obesity Epidemic • Create a child-healthy environment • Banish junk food from schools • Reduce food ads directed at children • Increase opportunities for physical activity
Psychological Factors and Obesity • Moral problem? • Psychological problem? • Aesthetic problem? • Social and medical problem?
Psychosocial Status of Obese Individuals Most obese individuals have normal psychological status Persons who seek weight loss report greater distress Patients at greatest risk of depression: Women Extreme obesity (BMI ≥ 40 kg/m2) Binge eating disorder (BED) Friedman & Brownell. Psych Bull 1995;117:3-20.
Risk of Major Depression with Extreme Obesity Onyike, et al. Amer J Epidemiology 2003;158:1139-1147.
Bodily Pain and Depression in Obese Individuals (N = 306) BDI-II Score Fabricatore AF. Obes Surg 2005; 15:304-309.
Prejudice Against the Obese Six-year old children labeled silhouettes of an overweight child as: Lazy Dirty Stupid Ugly Cheats Lies Staffieri. J Per Social Psychol 1967;7:101.
Prejudice Against the Obese 1961 2001 1 Healthy* 2 Healthy Crutches Face* Mean Rank 3 Wheelchair Crutches* Hand Hand 4 Face Wheelchair* Obese 5 Obese* 6 Latner, JD, Stunkard, AJ. Obes Res 2003;11:454.
Discrimination Against the Obese Discrimination has been reported in: Student Selection Employee Selection Employee Pay and Promotion Tenant Selection Marriage Roehling MV. Personnel Psychology 1999; 52: 969-1016.
Discrimination in the Workplace Discrimination against obese does not violate federal law in the US Title VII in US protects people from discrimination based on race, color, religion, sex, or national origin Obesity is not a protected characteristic
Social Stigma and Obesity: “I’d Rather Go Blind” Patients who lost 45 kg or more Preferred to be normal weight with a major handicap (deaf, dyslexic, diabetic, legally blind, bad acne, heart disease, leg amputated) than to be morbidly obese Rather be normal weight than a morbidly obese multi-millionaire Rand CS. Macgregor AM. Int J Obesity 1991; 15:577.
Conclusion The epidemic of obesity is the result of a complex interplay of genetic, environment, cultural, and economic factors Greater efforts are needed to change the environment that lies at the heart of the epidemic Obese individuals should not be blamed for their condition, but instead be treated with respect, fairness, and compassion