obesity overview
DESCRIPTION
The pTRANSCRIPT
Obesity - Basics
Pennington Biomedical Research CenterDivision of Education
Publication # 34
Introduction and definition
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Obesity: Introduction
A complex chronic disease with integration of social, behavioral, cultural, physiological, and genetic factors.Heart Disease was the number one leading cause of death in 2010, second was cancer, fourth was stroke, seventh was diabetes. All of these conditions - as well as depression, arthritis, and a host of others - are complications of obesity.
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Overweight is Rising
Time
Percent Overweight
% Overweight and Obesity0
10
20
30
40
50
60
70
80
19001950197019902008
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Body Mass Index (BMI)
BMI equals a person's weight in kilograms divided by height in meters squared. (BMI=kg/m2)Is a measurement taken into account by physicians and researchers studying obesity
BMI uses a mathematical formula that takes into account both a person's height and weight
1kg= 2.2 pounds1 inch= 2.54 cm
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Classification
Body mass index (BMI) kg/m2
– Optimal BMI is 20-25– Overweight is a BMI of 27 or greater– Obese BMI is 30 or greater
You can find tables on the web that have done the math and metric conversions for you. Simply locate your height in inches and weight in pounds to calculate BMI.Example of a chart:– http://www.nhlbi.nih.gov/guidelines/obesity/bmi_tbl.pdf
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Risk of Associated Disease According to BMI and Waist Size
BMI Waist less than or equal to40 in. (men) or35 in. (women)
Waist greater than40 in. (men) or35 in. (women)
18.5 or less Underweight --- N/A
18.5 - 24.9 Normal --- N/A
25.0 - 29.9 Overweight Increased High
30.0 - 34.9 Obese I High Very High
35.0 - 39.9 Obese II Very High Very High
40 or greater
Obese III Extremely High
Extremely High
http://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html#Definition
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Why is BMI of 20-25 considered as a reference weight?
This is because the relationship between morbidity and mortality and BMI was minimal at that range
0
0.5
1
1.5
2
2.5
19 20 25 35
Risk
Increased risk
Body Mass Index
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BMI
With the exception of highly trained athletes, Body Mass Index is a good predictor of chronic
disease and mortality.
Currently, about 74% of American adults are overweight and about 39.5% are obese.
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Cell size
All obese individuals have increased adipose cell size.As an adult gains weight, generally cell size increases, not cell numberSo, the number of fat cells can be associated with the age of onset of obesity.For adults with a higher number of adipose cells, this would indicate that obesity was present in early childhood.
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Total # of adipose cells in adults
0102030405060708090
100
L Men L Women O-Men O-Women
Lean
Obese
x106
Increasing in number
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Waist Circumference
Is a predictor of mortality and chronic disease Is a prognostic indicator along with BMIThe 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
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Obesity classes
Class 1– BMI of 30-35
Class 2– BMI of 35-40
Class 3, Extreme obesity– BMI greater than 40
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Facts on Obesity
All health problems are more common in in obese women than in men, with the exception of cardiac heart disease. Excess weight and even modest weight gains substantially increase the risk of Hypertension in adult women. Weight loss reduces this risk
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Facts on Obesity
Low resting metabolic rate (RMR) in formerly obese persons may be genetic or acquired and may contribute to weight regain once an individual is successful in a 10% weight loss.Visceral adipose tissue (VAT) distribution is an important determinant of RMR in men and postmenopausal women.
Co-morbidities
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Morbidity and Mortality associated with
Obesity
Cardiovasular disorders
– Hypertension– Stroke
– Ischemic heart disease
Individuals are at greater risk for developing:
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Hypertension
Blood pressure is often increased in overweight individuals.Estimates suggest that control of overweight would eliminate 48% of the hypertension in Caucasians and 28% in African Americans.Overweight and hypertension interact with cardiac function, leading to thickening of the ventricular walls and larger heart volume over time, and thus to a greater likelihood of cardiac failure.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
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Prevalence of HTN in overweight and obese individuals
Adapted from: http://www.obesityinamerica.org/trends.html
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Stroke
Ischemic stroke occurs when an artery to the brain is blocked. Normally, blood containing oxygen and nutrients is delivered to the brain and carbon dioxide and cellular wastes are removed.The risk for ischemic stroke in men and women is increased in both overweight and obesity.However, overweight and obesity do not increase the risk for hemorrhagic strokes.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
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Morbidity and Mortality associated with Obesity
Gastrointestinal disorders– Colon cancer– Diverticulosis – Gall stones– Hemorrhoids
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Gall stones
When compared to those having a BMI of 24 or less, – women with a BMI greater than 30 had a 2-fold
increased risk for symptomatic gallstones.– those with a BMI greater than 45 had a 7-fold increase.
Relative increased risk of symptomatic gallstones occurring with increasing BMI is less for men than for women.Obese patients that lose weight rapidly, possibly from gastric surgery, are at risk for development of gallstones.There are medications to reduce the likelihood of gallstone development.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
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Morbidity and Mortality associated with Obesity
Metabolic disorders– Diabetes mellitus
– Dyslipidemia
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Diabetes Mellitus
Type 2 DM is strongly associated with overweight and obesity in both genders and in all ethnic groups.
Risk for Type 2 DM increases with the degree and duration of overweight, along with greater central distribution of body fat (abdominal).
Weight loss or moderating weight gain over years reduces the risk of developing diabetes.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
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Diabetes Mellitus
In the Health Professionals Follow-up Study, a weight loss of 5-11 kg decreased the relative risk for developing diabetes by nearly 50%.
Type 2 DM was almost nonexistent with a weight loss of more than 20 kg or in those with a BMI below 20.
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Obesity and Type 2 DM
Among people diagnosed with Type 2 diabetes, 67 percent have a BMI > 27 (classified in the overweight range) and 46 percent have a BMI > 30 (classified as obese).
Obesity increases the risk for Type 2 diabetes in women more than 90 times for those with a BMI in the Class 2 range and above, and more than 40 times for men with a BMI in the Class 2 range and above.
Adapted from: http://www.obesityinamerica.org/trends.html
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Morbidity and Mortality associated with Obesity
Musculoskeletal disorders– Degenerative joint disease
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Morbidity and Mortality associated with obesity
Other– Sleep apnea
– Endometrial, prostate, and breast cancers– Complications of pregnancy
– Menstrual irregularities– Psychological disorders
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CancerOverweight and obesity are associated with an increased risk of:
esophageal, gallbladder, pancreatic, cervical, breast, uterine, renal, and prostate cancers.
Excess body weight, poor nutrition, or physical inactivity account for 30 percent of several major cancers, including--- colon, breast (postmenopausal), endometrial, kidney, and cancer of the esophagus. Excess body weight contributes to as many as 1 out of 5 of all cancer-related deaths.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005; www.cancer.org, 2012
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Infertility
Irregular menses, amenorrhea, and infertility are associated with obesity.
For women with a BMI greater than 30, abnormalities in the secretion of hypothalamic gonadotropin releasing hormone (GnRH), pituitary luteinizing hormone (LH), and follicle stimulating hormone (FSH) are likely to be present.
This results in anovulation.
Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
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Relative risk of death in women
1
1.2
1.4
1.6
1.8
2
2.2
2.4
19 19-21.9 22-24.9 25-26.9 27-28.9 29-31.9 32
Risk
Body Mass Index
Increased Risk
NEJM 1995;333:677-685.
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Total cost of Obesity
The medical care costs of obesity in the United States are staggering. In 2008 dollars, these costs totaled about $147 billion.
Direct and indirect costs comprise this total, and are roughly equal.
Direct Costs: include medical expenditures for preventative, diagnostic, and treatment services.
Indirect Costs: include lost wages resulting from people being unable to work because of illness.
CDC, 2012
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Death rates due to obesity
Obesity is associated with over 112,000 excess deaths due to cardiovascular disease, over 15,000 excess deaths due to cancer, and over 35,000 excess deaths due to non-cancer, non-cardiovascular disease causes per year in the U.S. population, relative to healthy-weight individuals..Reported that there are > 400,000 deaths a year attributed to tobacco-related diseases.
2007
Prevalence
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Prevalence
4 states had obesity prevalence rates of
15–19 percent
No state had a rate at or above 20
percent
0 states had obesity prevalence rates of
15-19 percent
15 states had rates of 20-24 percent
36 states had rates more than 25
percent
In 1991 In 10
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From the CDC: For 2010
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Comparisons:
15% of the US adults, 20 years or > had a BMI of
30 or > in 1971-74
Now 35.7% of the US have a BMI of 30 or
>(2008)
Obesity was at 5% in 1971-74.
17% of children and teens ages 2-19 are obese according to the
2007-2008 NHANES data
Adults: Youth:
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Prevalence in the US:
Non-Hispanic black women– 58.6%
Hispanic women– 40.7%
Non-Hispanic white women - 33.4%
Overweight and Obesity in Women(2009-2010)
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Obesity by Age and Race: In the US
http://www.gallup.com/poll/142736/obesity-peaks-middle-age.aspx
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Obesity by Income Level: In the US
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Obesity in other countries
Italy: 8.9%
Germany: 14.7%
England: 26%
Japan: 3.2%
Critical periods of growth
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Periods of rapid growth
Childhood
Teen age years
Pregnancy
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Obesity in children: Facts
Among children older than 3, obesity is a strong predictor of adult obesity
Parental obesity more than doubles the risk of adult obesity among both obese and non-obese
children under 10.
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Ten State Nutrition Survey
The study follows girls and boys born to different parental combinations, measuring and recording skin fold thickness each year from age
three until seventeen. Depending on which combination the child was born to, this either puts the child at higher or lower risk for being overweight later
in life.Uses 5 different parental combinations:
Lean and LeanMedium and Lean
Medium and MediumMedium and ObeseObese and Obese
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5 Parental fatness combinations
Lean Lean Medium Lean Medium Medium
L-L M-L M-M
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5 Parental fatness combinations
Obese Medium Obese Obese
O-M O-O
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Tricep skinfold in boys
0
5
10
15
20
25
30
3 5 7 9 11 13 15 17
O-O
O-M
M-M
M-L
L-L
Age (Years)
Parental Fatness Combinations
Mm
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Tricep skinfold in girls
0
5
10
15
20
25
30
3 5 7 9 11 13 15 17
O-O
O-M
M-M
M-L
L-L
Age (years)
Mm
Parental Fatness Combinations
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Obesity in children
Comparing the children of obese with the children of lean, it was striking both how fat the children of the obese were, and how fast they gained their fatness.
By age 17, the children of two obese parents were three times as fat as the children of two lean parents.
Ten State Nutrition Survey
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Childhood antecedents to obesity
Parental weightSocial classRaceOne-parent householdEducational levelParental incomeParental employment
TV viewing# siblingsMaternal ageHigh caloric intakeHigh dietary fat intakePhysical activity levelReduced Thermic Effect of Food
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SE & Obesity
Higher socioeconomic group women:diet more oftenhave greater access to resourceshave better nutrition knowledgeare committed to slimnessavoid high fat foods get more physical activity
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Effect of Socioeconomic Group in the Developing Countries
Completely reversedHigher socioeconomic classes have more incidence of obesityLess malnutritionLess infectionSteady source of income and foodOverweight is associated with wealth
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Obesity versus SE
Thinness
Affluence
Prevalence
Obesity
Diet and obesity
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Energy balance
Body weight is a function of energy and nutrient balance over an extended period of time.Energy balance is determined by macronutrient intake, energy expenditure, and nutrient partitioning.Some possible causes of obesity include:
Cessation of smoking, over-consumption of high fat foods,
a decrease in the level of activity, and aging.
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Fat versus carbohydrate
Fat is more energy dense than carbohydrates, yielding 38kJ/g versus carbohydrates 17kJ/g.9 kcals/g of fat versus 4.0 kcals/g of carbohydrateFats lend flavor and palatability to foods contributing to greater preference for them.Carbohydrates have greater thermogenic effect than fats.
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Dietary fat versus calories
Reducing dietary fat has very little effect on reducing body weight as long as energy balance is met.Total calories and caloric balance is more importantOvereating is necessary initially for weight gain to occur
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Dietary fat intake is decreasing while Obesity is
increasing.1970’s people ate an average of– 85 grams of fat– 1,837 kcal
1994 people ate an average of– 73 grams of fat– 1,949 kcal
1994-96 people ate an average of – 76. 4 grams of fat– 2,056 kcal
– Although we are still consuming less fat, we are consuming more (larger portion sizes), contributing to more calories consumed per day than in the 1970’s.
Chanmugam et al 2003.
Heritability of obesity
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Genetics and Environment
All individuals
Those genetically
predisposed
Clinically affected
~3%
Portion subject to adverse
environmental conditions
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Genetics
Obesity is probably genetically predisposed in a small percent of the population.
The National Institutes of Health (NIH) estimates that environment contributes 40-60% of weight determination.
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Obesity Genes
Common variants in three genes have been associated with an increased risk for obesity
– Individuals who have 12 variants in their 3 genes could gain around 6 kg of extra body weight compared to someone who does not (13+ pounds of extra weight)
Nature Genetics (2009) 41: 140.
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Heritability
Identical twins reared apart yield highest heritability levels ~70%
Adoption studies yield lowest habitability estimates ~30%
True heritability for BMI is about
~25-40% already determined.
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Human obesity genes: Pennington Biomedical Research Center
An abundance of research is currently being conducted on human obesity genes and their role in the development of obesity in individuals.
There are at least 135 different genes in humans that have been associated and/or linked with obesity-related phenotypes. Currently 22 genes have been identified in several studies including the following 12 in up to 10 studies: PPARG, ADRB3, ADRB2, LEPR, GNB3, UCP3, ADIPOQ, LEP, UCP2, HTR2C, NR3C1, and UCP1. The genes have been found distributed in all chromosomes except Y.
Rankinen et al. OBESITY Vol. 14 No. 4 April 2006
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Future Directions
Obesity is a chronic disorder which is currently on the rise.One should set realistic goals for weight loss. Even modest weight losses of 5-10% initial body weight show improvements in overall health and decreased risk for complications from chronic disease.Behavioral treatment is necessary with a focus on relapse prevention. Combination treatments are often incorporated
– Drug, diet, exercise, behavior
Thank You!
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References
http://www.contracostatimes.com/mld/cctimes/8145335.htm?template=contentModules/printstory.jsp&1c http://www.consumer.gov/weightloss/bmi.htm http://www.cdc.gov/nccdphp/dnpa/obesity/defining.htm http://www.wvdhhr.org/bph/oehp/obesity/economic.htm http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/index.htm http://www.cdc.gov/nchs/pressroom/04facts/obesity.htm http://www.uic.edu/depts/mcam/nutrition/pdf/EnergyBalance.pdf#search='energy%20expenditure%20RMR%20thermogenesis‘ http://win.niddk.nih.gov/publications/gastric.htm Escott-Stump, S. Nutrition and Diagnosis-Related Care. 5th Edition. 2002
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References
http://www.americanheart.org/presenter.jhtml?identifier=4720 http://www.strokecenter.org/pat/ais.htm http://cis.nci.nih.gov/fact/3_70.htm http://www.obesityinamerica.org/trends.html http://obesitygene.pbrc.edu/~eesnyder/papers/OGM2003_paper.pdf http://www.google.com/imghp?hl=en&tab=wi&qRankinen et al. OBESITY Vol. 14 No. 4 April 2006http://www.gallup.com/poll/142736/obesity-peaks-middle-age.aspxNature Genetics (2009) 41: 140
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Pennington Biomedical Research Center
Division of Education
Division of EducationPhillip Brantley, PhD, DirectorPennington Biomedical Research CenterClaude Bouchard, PhD, Executive DirectorHeli J. Roy, PhD, RDShanna Lundy, BS Beth Kalicki
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 ResearchExperimental ObesityFunctional FoodsHealth and Performance EnhancementNutrition and Chronic DiseasesNutrition and the BrainDementia, Alzheimer’s and healthy agingDiet, 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.
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