Obesity Risk Factors and Associated Health Conditions

Obesity
And its Associated Risk Factors
Pennington Biomedical Research Center
Division of Education

2009
Obesity
An Overview
 Overweight and obesity are both chronic
conditions that are the result of an energy
imbalance over a period of time.
 The cause of this energy imbalance can be due
to a combination of several different factors and
varies from one person to another.
 Individual behaviors, environmental factors, and
genetics all contribute to the complexity of the
obesity epidemic.
CDC

2009
Energy Imbalance
What is it?
 Energy balance can be compared to a scale.
 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 through physical activity.
Weight Gain
Calories Consumed > Calories Used
Weight Loss
Calories Consumed < Calories Used
No Weight Change
Calories Consumed = Calories Used
CDC

2009
Energy Imbalance
Effects in the Body
 Excess energy is stored in fat cells, which enlarge or multiply.
 Enlargement of fat cells is known as hypertrophy,
whereas multiplication of fat cells is known as
hyperplasia.
 With time, excesses in energy storage lead to obesity.
Fat cells
J La State Med Soc .2005; 156 (1): S42-49.

2009
Weight Classifications
A Review
 Body mass index (BMI) is a
mathematical ratio which is calculated
as weight (kg)/ height squared (m2
).
It is used to describe an
individuals relative weight for height, and
is significantly correlated with total
body fat content. BMI is intended
for those 20 years of age and older.
With a BMI of: You are considered:
Below 18.5 Underweight
18.5 - 24.9 Healthy Weight
25.0 - 29.9 Overweight
30 or higher Obese
You can find tables on the web that have done the math and metric conversions for you.
http://www.pbrc.edu/Division_of_Education/Tools/BMI_Calculator.asp
or
http://www.nhlbisupport.com/bmi
CDC

2009
Mo rtality and Mo rbidity
Associated with Obesity
 The effects of excess weight on mortality and morbidity have been recognized
for more than 2,000 years. It was Hippocrates who recognized that “sudden
death is more common in those who are naturally fat than in the lean.”
 Today, obesity is increasing rapidly. Research shows that many factors related
to obesity influence mortality and morbidity.
Endocrinol Metab Clin N Am. 2003; 32: 761-786.

2009
Mortality
Weight, Fat Distribution, and Activity
 The following factors have been shown to increase
mortality in individuals:
 Excess body weight
 Regional fat distribution
 Weight gain patterns
 Sedentary Lifestyle

2009
Mortality
Excess Body Weight
 Mortality associated with excess body weight increases as
the degree of obesity and overweight increases.
 It is estimated that 280,000 to 325,000 deaths a year can
be attributed to obesity in the United States, more than 80%
of these deaths occur among individuals with a BMI greater
than 30 kg/m2
.

2009
 Regional fat distribution can contribute to mortality.
 This was first noted in the beginning of the 20th
century.
 Obese individuals with an android (or apple) distribution of body fat are at a
greater risk for diabetes and heart disease than were those with a gynoid
distribution (pear).
 Android fat distribution results in higher free fatty acid levels, higher glucose
and insulin levels and reduced HDL levels. It also results in higher blood
pressure and inflammatory markers.
Mortality
Regional Fat Distribution
Android Gynoid

2009
 In addition to overweight and central fatness,
the amount of weight gain after ages 18 to 20
also predicts mortality.
 The Nurses’ Health Study and the Health
Professionals Follow-up Study showed that
a marked increase in mortality from heart
disease is associated with increasing
degrees of weight gain.
Mortality
Weight Gain

2009
 Sedentary lifestyle is another important component
in the relationship of excess mortality to obesity.
 A sedentary lifestyle increases the risk of death
at all levels of BMI.
 Unfit men in the BMI range of less than 25 kg/m2
had a significantly higher risk than men with a
high level of cardiovascular fitness.
 Obese men with a high level of fitness had risks
of death that were not different from fit men with
normal body fat.
Mortality
Sedentary Lifestyle

2009
Mo rbidity
 Overweight affects several diseases, although
its degree of contribution varies from one
disease to another.
 Additionally, the risk of developing a disease
often differs by ethnic group, and by gender
within a given ethnic group.

2009
 Obstructive sleep apnea
 Osteoarthritis
 Cardiovascular disorders
 Gastrointestinal
disorders
 Metabolic disorders
 Endometrial, prostate
and breast
cancers
 Complications of pregnancy
 Menstrual irregularities
 Psychological disorders
Individuals who are obese are at a greater risk of developing:
Morbidity
CDC

2009
Cardiovascular Disorders
Hypertension
Stroke
Coronary Artery Disease
Obese individuals are at a greater risk of developing these cardiovascular disorders:

2009
Hypertension
 Hypertension (HTN) is the term for high blood pressure.
 Hypertension is identified when a blood pressure is
sustained at ≥140/90 mmHg.
 High blood pressure is referred to as the “silent killer,”
since there are usually no symptoms with HTN.
 Some individuals find out that they have high blood
pressure when they have trouble with their heart, brain,
or kidneys.
NHLBI

2009
Hypertension
The Dangers
 The heart to get larger, which may lead to heart failure.
 Small bulges (aneurysms) to form in blood vessels.
 Blood vessels in the kidney to narrow, which may lead to kidney failure.
 Arteries in the body to harden faster, especially those in the
heart, brain, kidneys, and legs. This can cause a heart attack, stroke,
kidney failure, or can lead to amputation of part of the extremities.
 Blood vessels in the eye to burst or bleed. This may cause
vision changes and can result in blindness.
Failure to find and treat HTN is serious, as untreated HTN can cause:
NHLBI

2009
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
wall and larger heart volume, and thus to a
greater likelihood of cardiac failure.

2009 Adapted from:
http://www.obesityinamerica.org/trends.html
Hypertension
Prevalence in the Overweight
0
5
10
15
20
25
30
35
Males Females
BMI < 25
BMI > 25 & < 27
BMI > 27 & <30
PrevalenceofHTN
Age-adjusted prevalence
of hypertension in
overweight U.S. adults
14.9
22.1
27.0
15.2
27.7
32.7

2009
Stroke
 Normally, blood containing oxygen and
nutrients is delivered to the brain, and carbon
dioxide and cellular wastes are removed.
 A stroke occurs when the blood supply to
part of the brain is suddenly interrupted by a
blocked vessel or when a blood vessel in the
brain bursts.
 Once their supply of oxygen and nutrients
from the blood is cut off to the brain cells,
they die.
NINDS

2009
Stroke
 Sudden numbness or weakness, especially on one side of the body
 Sudden confusion or trouble speaking or understanding speech
 Sudden trouble seeing in one or both eyes
 Sudden trouble with walking, dizziness, or loss of balance or coordination
 Sudden severe headache with no known cause
The symptoms of a stroke include:
NINDS

2009
Stroke
 There are two forms of stroke: ischemic and hemorrhagic.
 Ischemic stroke occurs when an artery to the brain is blocked.
 Overweight and obesity increase the risk for ischemic stroke in men and women.
 With increasing BMI, the risk of ischemic stroke increases progressively and is
doubled in those with a BMI greater than 30 kg/m2
when compared to those
having a BMI of less than 25 kg/m2
.
 Hemorrhagic strokes occur when a blood vessel in the brain erupts.
 Overweight and obesity do not increase the risk for hemorrhagic strokes.
NINDS

2009
 Coronary artery disease (CAD) is a type of atherosclerosis that occurs when the arteries
supplying blood to the heart muscle (coronary arteries) become hardened and narrowed.
 This hardening and narrowing is caused by plaque buildup.
 As the plaque increases in size, the insides of the coronary arteries get narrower, and
eventually, blood flow to the heart muscle is reduced.
 This is critical because blood carries much-needed oxygen to the heart.
NHLBI

2009
Coronary Arteries
Blood Flow
 When the heart muscle is not
receiving the amount of oxygen
that it needs, one of two things
can happen:
 Angina
 Heart Attack
Angina
This is the chest pain or discomfort that occurs
when the heart is not getting enough blood.
Heart attack
This is what happens when a blood clot develops
at the site of the plaque in a coronary artery.
The result is a sudden blockage, which may
block all or most of the blood supply to the heart
muscle. Because cells in the heart muscle begin to
die when they are not receiving adequate amount
of oxygen, permanent damage to the heart muscle
can occur if blood flow is not quickly restored.
NHLBI

2009
 Over time, CAD can weaken
the heart muscle and
contribute to:
 Heart Failure
 Arrhythmias
Heart Failure
In this condition, the heart can’t pump blood
effectively to the rest of the body. Heart
failure does not mean that the heart has
stopped nor does it mean that it is about to.
It means that the heart is failing to pump
blood the way that it should.
Arrhythmias
Arrhytmias are changes in the normal
beating rhythm of the heart. They can be
either faster or slower than normal.
Some arrhythmias can be quite
serious.
NHLBI

2009
 Obesity is associated with an increased risk for CAD.
 Abdominal fat distribution is believed to be related as well.
 Data from the Nurses Health Study illustrated that women in the lowest BMI but
highest waist-to-hip circumference ratio had a greater risk of heart attack than
those in the highest BMI but lowest waist-to-hip circumference ratio.
 Regional fat distribution appears to have a greater effect on CAD risk than BMI alone.

2009
Gastrointestinal Disorders
Obese individuals are at greater risk of developing these gastrointestinal disorders:
Colon Cancer
Gall stones

2009
Colon Cancer
 Colorectal cancer is a term used to refer to cancer that
develops in the colon or the rectum.
 The colon (a.k.a. the large intestine) is about 5 feet long and its
role in the digestive system is to continue to absorb water and
mineral nutrients from food. Once this process of absorption is
complete, waste matter (feces) remains.
 The rectum is the final 6 inches of the digestive system. Feces
are passed from the large intestine to the rectum, to exit the
body through the anus.
American Cancer Society

2009
Colon Cancer
 Colorectal cancer is the second leading cause of cancer-related deaths in the U.S.
 It is estimated to cause about 55,170 deaths during 2006.
American Cancer Society

2009
Colon Cancer
Findings Relating to Obesity
 Colon cancer has been shown to occur more
frequently in people who are obese than in
people who are of a healthy weight.
 An increased risk of colon cancer has been
consistently reported for men with high BMIs.
 Women with high BMI are not at increased risk
of colon cancer.
There is evidence that abdominal obesity may be
important in colon cancer risk.
NCI

2009
Gallbladder Disease
 Cholelithiasis is the primary hepatobiliary pathology associated with overweight.
 Cholelithiasis is a condition characterized by the presence or formation of
gallstones in the gallbladder or bile ducts.
 Normally, a balance of bile salts, lecithin, and cholesterol keep gallstones from
forming. However, if there are abnormally high levels of bile salts or, more
commonly, cholesterol, then stones can form.
NIH

2009
Gallstones
Findings Related to Obesity
 Obesity appears to be associated with the development of gallstones.
 More cholesterol is produced at higher body fat levels.
 Approximately 20 mg of additional cholesterol is synthesized for each kg of extra
body fat.
 High cholesterol concentrations relative to bile acids and phospholipids in bile
increase the likelihood of precipitation of cholesterol gallstones in the gallbladder.

2009
Gallstones
 In the Nurses’ Health Study, when compared to those having a BMI of 24 or less,
 Women with a BMI > 30 kg/m2
had a 2-fold increased risk for symptomatic gallstones.
 Women with a BMI > 45 kg/m2
had a 7-fold increased risk for symptomatic gallstones.
 The relative increased risk of symptomatic gallstone development with increasing BMI
appears to be less for men than for women.

2009
Gallstones
 Ironically, weight loss leads to an increased risk of gallstones--
because of the increased flux of cholesterol through the biliary
system.
 Diets with moderate levels of fat that trigger gallbladder
contraction and subsequent emptying of the cholesterol content
may reduce the risk of gallstone formation.
 Bile acid supplementation can be used to lower ones risk for
gallstone formation.

2009
Metabolic Disorders
Obese individuals are at greater risk of developing these metabolic disorders:
Diabetes Mellitus
Dyslipidemia
Liver Disease

2009
Diabetes Mellitus
 Type 2 diabetes mellitus (DM) is strongly associated with
overweight and obesity in both genders and in all ethnic groups.
 The risk for Type 2 DM increases with the degree and duration
of overweight in individuals.
 The risk for Type 2 DM also increases in individuals with a
more central distribution of body fat (abdominal).

2009
Obesity and Type 2 DM
In the United States
Among people diagnosed
with Type 2 diabetes,
55 percent have a BMI
≥ 30 (classified as obese),
30 percent have a
BMI ≥ 25 or ≤30
(classified as
overweight), and only 15
percent have a BMI ≤ 25
(classified as normal weight).
Adapted from:
BMI < 25
BMI > 25 or BMI < 30
BMI > 30
15%
30%55%

2009
Diabetes Mellitus
 The Nurses’ Health Study demonstrated the curvilinear relationship
between increasing BMI and the risk of diabetes in women:
 Women with a BMI below 22 kg/m2
had the lowest risk of DM
 At a BMI of 35 kg/m2
, the relative risk of DM increased 40-fold or 4,000%
 The Health Professionals Follow-up Study demonstrated a similar
relationship between increasing BMI and the risk of diabetes in men:
 Men with a BMI below 24 kg/m2
had the lowest risk of DM
 At a BMI of 35 kg/m2
, the relative risk of DM increased 60-fold or 6,000%

2009
Diabetes Mellitus
Findings Relating to Weightloss
 Weight loss reduces the risk of developing diabetes.
 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 (44 lbs) or in those with a BMI below 20.

2009
Dyslipidemia
 Dyslipidemia is defined as
abnormal concentration of
lipids or lipoproteins in the
blood.
 As BMI increases, there is an
increased risk for heart
disease.
 This is because a positive
correlation between BMI and
triglyceride (TG) levels has
been demonstrated.

2009
Dyslipidemia
 An inverse relationship between HDL cholesterol and BMI has been noted.
 This relationship may be more important than the relationship between
BMI & TG levels.
 Low level of HDL carries more relative risk for developing heart disease
than do elevated triglyceride levels.
 Central fat distribution also plays an important role in lipid abnormalities.
 Excessive body fat in the abdominal region leads to increased circulating
triglyceride levels.
HDL

2009
Liver Disease
 Nonalcoholic fatty liver disease (NAFLD) is the term
given to describe a collection of liver abnormalities
that are associated with obesity.
 In a cross-sectional analysis of liver biopsies of
obese patients, it was found that the prevalence of
steatosis, steatohepatitis, and cirrhosis were
approximately 75%, 20%, and 2% respectively.

2009
Liver Disease
Fatty Liver
 Steatosis is the term for “fatty liver” and it is not
actually a disease, but rather a pathological finding.
 Most cases of fatty liver are due to obesity.
 Other causes of fatty liver include:
 Diabetes
 Certain drugs
 Intestinal bypass operations
 Starvation
 Protein malnutrition
 Alcoholism
The American Liver Foundation

2009
Liver Disease
Fatty Liver
 A gradual weight reduction can help to
reduce the enlargement of the liver due to
fat, and it can normalize the associated liver
test abnormalities.
 It is important to limit the amount of alcohol
consumed in the diet. Alcohol can decrease
the rate of metabolism and secretion of fat
in the liver.
The American Liver Foundation

2009
Importance of a Healthy Liver
 The 300 billion cells of the liver control a process known as metabolism. During
metabolism, the liver breaks down nutrients into usable products. These products
are then delivered to the rest of the body through the bloodstream.
 The liver also metabolizes toxins into byproducts that can be safely eliminated.
 The liver also produces many important substances, such as: albumin, bile,
cholesterol, clotting factors, globin, and immune factors.
The liver is the largest organ in the body and it plays a vital role in performing
many complex functions that are essential for life:
Mayo Clinic

2009
Obstructive sleep apnea
Osteoarthritis
Endometrial, prostate, and breast cancers
Complications of pregnancy
Menstrual irregularities
Psychological disorders
Other Disorders
Obese individuals are at greater risk of developing these metabolic disorders:

2009
Obstructive Sleep Apnea
 Obstructive sleep apnea is caused by repetitive upper airway obstruction during sleep
as a result of narrowing of the respiratory passages.
 Patients having the disorder are most often overweight with associated peripharyngeal
infiltration of fat and/or increased size of the soft palate and tongue.
American Academy of Family Physicians

2009
 Common complaints are loud snoring, disrupted sleep,
and excessive daytime sleepiness.
 Individuals with sleep apnea suffer from fragmented sleep
and may develop cardiovascular abnormalities because of
the repetitive cycles of snoring, airway collapse, and
arousal.
 Because many individuals are not aware of heavy snoring
and nocturnal arousals, obstructive sleep apnea may remain
undiagnosed.
American Academy of Family Physicians

2009
 Obstructive sleep apnea affects around 4% of middle-aged adults.
 Individuals having a BMI of at least 30 are at greatest risk for sleep apnea.
 Weight loss has been shown to improve the symptoms relating to sleep apnea.

2009
Osteoarthritis
 Osteoarthritis (OA) is the most common type of arthritis
 40 million Americans currently have osteoarthritis.
 It is a degenerative disease which frequently leads to chronic pain and disability.
 For individuals over the age of 65, it is the most disabling disease.
 Currently, only the symptoms of OA can be treated; there is no cure.
NSLS

2009
Osteoarthritis
 The incidence of OA is significantly increased in overweight individuals.
 OA that develops in the knees and ankles is probably directly related to
the trauma associated with the degree of excess body weight.
 Osteoarthritis in other non-weight bearing joints suggests that there
must be some component of the overweight syndrome responsible
for altering cartilage and bone metabolism, independent of the
actual stresses of body weight on joints.
Areas of the body
most commonly
affected by OA
NSLS

2009
Cancer
 Overweight and obesity are associated with an increased risk of:
esophageal, gallbladder, pancreatic, cervical, breast, uterine,
renal, and prostate cancers.
 Obesity and physical inactivity may account for 25 to 30 percent of
several major cancers, including--- colon, breast
(postmenopausal), endometrial, kidney, and cancer of the
esophagus.

2009
Endocrine Changes
 There are various endocrine changes associated with overweight.
 Changes in the reproductive system are among the most common.
 Irregular menses and frequent anovular cycles are common.
 Rates of fertility may also be reduced.

2009
Endocrine Changes
 Increased cortisol production
 Insulin resistance
 Decreased sex hormone-binding globulin in women
 Decreased progesterone levels in women
 Decreased testosterone levels in men
 Decreased growth hormone production
Common hormonal abnormalities associated with obesity

2009
Psychological Disorders
Associations with Obesity
 Obesity is associated with an impaired quality of life.
 Higher BMI values are associated with greater adverse effects.
 When compared to obese men, obese women appear to be at
a greater risk for psychological dysfunction.
 This may be due to the societal pressure on women to be thin.

2009
Psychological Disorders
Weight Loss
 Intentional weight loss has been
consistently associated with improved
quality of life.
 Severely obese patients who lost 43 kg
through gastric bypass demonstrated
improved quality of life scores to such an
extent that their post-weight loss scores
were equal to or even better than
population norms.

2009
In Conclusion
 Diabetes mellitus
 Hypertension
 Gallbladder Disease
 Liver Disease
 Cancer
 Coronary Artery Disease
 Cerebrovascular disease (stroke)
 Endocrine Changes
 Psychosocial Function
 Obstructive Sleep Apnea
 Osteoarthritis
The following conditions have been found to be associated with obesity:
These diseases have been found to be
associated with increased metabolic
activity (secretion) of fat cells in obesity
These diseases have been found to be
associated with increased fat mass

2009
Pennington Biomedical Research
Center
Division of Education
Phillip Brantley, PhD, Director
Pennington Biomedical Research
Center
Claude Bouchard, PhD, Executive
Director
Phillip Brantley, PhD, Director
Heli J Roy, PhD, RD, Associate Professor
Shanna 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 Research
 Experimental Obesity
 Functional Foods
 Health and Performance Enhancement
 Nutrition and Chronic Diseases
 Nutrition and the Brain
 Dementia, Alzheimer’s and healthy aging
 Diet, 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.
2009

2009
References
 CDC: Overweight and Obesity -- Contributing Factors. Available at:
http://www.cdc.gov/nccdphp/dnpa/obesity/contributing_factors.htm
 Bellanger T, Bray G. Obesity related morbidity and mortality.
J La State Med Soc. 2005; 156(1): S42-49.
 Bray G. Risks of obesity. Endocrinol Metab Clin N Am. 2003; 32: 787-804.
 National Heart, Lung, and Blood Institute (NHLBI). High Blood Pressure.
Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP_WhatIs.html
 Obesity in America. Obesity Trends. Available at:

2009
References
 National Institute of Neurological Disorders and Stroke. NINDS Stroke Information Page.
Available at: http://www.ninds.nih.gov/disorders/stroke/stroke.htm
 National Heart, Lung, and Blood Institute (NHLBI). What is Coronary Artery Disease?
Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html
 American Cancer Society (ACS). What is Colorectal Cancer? Available at:
http://www.cancer.org/docroot/CRI/content/CRI_2_4_1x_What_Is_Colon_and_Rect
um_Cancer.asp?rnav=cri
 National Cancer Institute (NCI). Obesity and Cancer. Available at:
http://www.cancer.gov/cancertopics/factsheet/Risk/obesity

2009
References
 American Liver Foundation. Diet and Your Liver. Available at:
http://www.liverfoundation.org/cgi-bin/dbs/articles.cgi?
db=articles&uid=default&ID=1022&view_records=1
 Mayo Clinic. Your Liver: An Owner’s Guide. Available at:
http://www.mayoclinic.com/health/liver/DG00038
 American Academy of Family Physicians (AAFP). Obstructive Sleep Apnea.
Available at: http://www.aafp.org/afp/991115ap/2279.html
 National Synchrotron Light Source (NSLS). Osteoarthritis. Available at:
http://www.nsls.bnl.gov/about/everyday/osteoarthritis.html

Obesity Risk Factors and Associated Health Conditions

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