Assessment of the Obesity Epidemic
More than 60% of US Adults Are Overweight
Flegal K, et al. JAMA 2002;288:1723-1727. Hedley AA, et al. JAMA 2004;291:2847-2850.
Obese (BMI ≥ 30)
Overweight (BMI 25 - 29.9)
Assessing Obesity: What Is BMI?
• 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
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.
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
0
10
20
30
40
50
60
70
80
90
100
20 - 34 35 - 44 45 - 54 55 - 64 65 - 74 75 andOverAge in Years
% o
f M
ale
Pop
ulat
ion
.
ObeseOverweight
Flegal et al. JAMA 2002;288:1723-1727.
0
10
20
30
40
50
60
70
80
90
100
20 - 34 35 - 44 45 - 54 55 - 64 65 - 74 75 andOver
Age in Years
% o
f Fem
ale
Pop
ulat
ion
Obese
Overweight
Prevalence of Obesity by Age
Men Women
Obesity Trends by Gender and Ethnicity
28 29 29
0
10
20
30
40
50
60
White Men Black Men Mexican Men
Pre
vale
nce
of O
besi
ty
.
31
51
40
0
10
20
30
40
50
60
WhiteWomen
Black Women MexicanWomen
Pre
vale
nce
of O
besi
ty
.
Men Women
Flegal K, et al. JAMA 2002;288:1723-1727.
Flegal et al. JAMA 2002;288:1723-1727.
Education
Ave
rage
BM
I
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
Income
23.0023.50
24.0024.5025.00
25.5026.0026.50
27.0027.50
Ave
rage
BM
I
198619
8819
9019
9219
9419
9619
9820
0020
02
Year
Lowest IncomeHighest Income
Prevalence of Obesity by Education and Income
Prevalence of Extreme Obesity (BMI ≥ 40) by Gender and Ethnicity
3.3 3.42.9
0
1
2
3
4
5
6
7
8
9
10
White Men Black Men MexicanMen
Pre
vale
nce
of E
xtre
me
Ob
esi
ty (
%)
5.5 5.7
13.5
0
2
4
6
8
10
12
14
16
WhiteWomen
Black Women MexicanWomen
Pre
vale
nce
of E
xtre
me
Obe
sity
(%
)
Men Women
Hedley AA, et al. JAMA 2004;291:2847-2850.
0
2
4
6
8
10
12
14
16
18
NHES II &III1963-70
NHANES I1971-74
NHANES II1976-80
NHANES III1988-94
NHANES1999-2002
Pre
vale
nce
of O
verw
eigh
t
.
Aged 6-11 years Aged 12-19 years
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.
Coronary Heart Disease
Morbiditymortality
Morbiditymortality
Morbiditymortality
Hypertension Diabetes Dyslipidemia
40% are obese 80% are obese 50% – 70% are obese
OBESITY
Obesity and Coronary Heart Disease (CHD)
0
5
10
15
20
25
30
35
40
45
50
NHANES I1971-1975
NHANES II1976-1980
NHANES III1988-1994
NHANES1999-2000
% o
f P
op
ula
tio
n
.
Trends in Cardiovascular Risk Factors in Obese Individuals (BMI ≥ 30 kg/m2 )
Smoking
High Cholesterol
High Blood Pressure
Gregg EW, et al. JAMA 2005;293:1868-1874.
Diabetes
Obesity Is Caused by Long-Term Positive Energy Balance
Fatstores
Energyintake
Energyexpenditure
Regulation of Body Weight
• Genes confer the potential for obesity
• Environment determines whether and to what extent the potential is realized
Relationship Between Adoptee Weight and Weight of Biological or Adoptive Parents
Stunkard et al. N Engl J Med 1986;314:193.
Weight Classification of Adoptees
BM
I of
Par
ents
(kg
/m2 )
Thin Median Overweight ObeseThin Median Overweight Obese
Biological Parents Adoptive Parents27
21
26
25
24
23
22Fathers
Mothers
Heritability of Body Weight
Sedentary person
(1800 kcal/d)Physically active person
(2200 kcal/d)
60%
Components of Daily Energy Expenditure
32%
75%
8% 17% 8%
Thermic effect of feeding
Resting energy expenditure
Energy expenditure of physical activity
Decreased Energy Expenditures and Weight Gain
0 1 2 3 40
5
10
15
20
25
30
Cu
mu
lati
ve I
nci
den
ce o
f a
10-k
g B
od
y W
eig
h G
ain
(%
)
Time (years)
Low RMR Middle RMR High RMR
Ravussin E, et al. N Engl J Med. 1988;318:467-472.RMR = resting metabolic rate
Barsh GS, Schwartz MW. Nat Rev Genet. 2002;3:589-600.
Gene-Environment Interaction in the Pathogenesis of Obesity
Pima Indians inMaycoba, Mexico
Pima Indians inArizona
Ravussin E et. al. Diabetes Care 17:1067, 1994.
0
10
20
30
40
50 p < 0.0001
Body Mass Index (kg/m2)
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
Nielsen & Popkin, JAMA 2003.
Food Portion Size Trends
0
5
10
15
20
SaltySnacks
Desserts SoftDrinks
FruitDrinks
FrenchFries
Ham-burgers
Cheese-burgers
Pizza MexicanFood
Foo
d In
take
per
Ea
ting
Occ
asio
n,
oz
1977-19781989-19911994-1998
0
5
10
15
20
25
30
35
40
TV hours per day (youth report)
Pre
vale
nce
(%)
NHES 1967-1970
NLSY 1990
0 - 1 1 - 2 2 - 3 3 - 4 4 - 5 > 5
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
20%
43%
70%
80%
0
10
20
30
40
50
60
70
80
90
1969 1979 1989 1999
American Academy of Pediatrics.
% of Children withDaily Physical Education
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.
1.13 1 0.961.33
1.9
4.63
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
< 18.5 18.5 - 24.9 25 - 29.9 30 - 34.9 35 - 39.9 > 40
Body Mass Index (kg/m2)
Odd
s R
atio
Bodily Pain and Depression in Obese Individuals (N = 306)
0
2
4
6
8
10
12
14
16
18
20
40 - 49.9 50 - 59.9 60 +
Body Mass Index
Not Impaired
Impaired
Fabricatore AF. Obes Surg 2005; 15:304-309.
BD
I-II
Sco
re
Bodily Pain:
Prejudice Against the Obese
Six-year old children labeled silhouettes of an overweight child as:
Staffieri. J Per Social Psychol 1967;7:101.
•Lazy
•Dirty
•Stupid
•Ugly
•Cheats
•Lies
Prejudice Against the Obese
1961 20011
2
3
4
5
6
Mea
n R
ank
Healthy
Healthy*
Crutches
Crutches*Wheelchair
Wheelchair*
HandHand
Face
Face*
Obese
Obese*
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
• 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
Social Stigma and Obesity: “I’d Rather Go Blind”
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