Obesity Statistics

Body Fat Distribution

Health care providers are concerned not only with how much fat a person has, but also where the fat is located on the body. Women typically collect fat in their hips and buttocks, giving them a “pear” shape. Men usually build up fat around their bellies, giving them more of an “apple” shape. Of course some men are pear-shaped and some women become apple-shaped, especially after menopause.

Excess abdominal fat is an important, independent risk factor for disease. Research has shown that waist circumference is directly associated with abdominal fat and can be used in the assessment of the risks associated with obesity or overweight. If you carry fat mainly around your waist, you are more likely to develop obesity-related health problems. Women with a waist measurement of more than 35 inches and men with a waist measurement of more than 40 inches may have more health risks than people with lower waist measurements because of their body fat distribution.

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What Causes Obesity?

Obesity occurs when a person consumes more calories from food than he or she burns. Our bodies need calories to sustain life and be physically active, but to maintain weight we need to balance the energy we eat with the energy we use. When a person eats more calories than he or she burns, the energy balance is tipped toward weight gain and obesity.This imbalance between calories-in and calories-out may differ from one person to another. Genetic, environmental, and other factors may all play a part.

Genetic Factors

Obesity tends to run in families, suggesting a genetic cause. However, families also share diet and lifestyle habits that may contribute to obesity. Separating genetic from other influences on obesity is often difficult.
Even so, science does show a link between obesity and heredity.

Environmental and Social Factors

Environment strongly influences obesity. Consider that most people in the United States alive today were also alive in 1980, when obesity rates were lower. Since this time, our genetic make-up has not changed, but our environment has.

Environment includes lifestyle behaviors such as what a person eats and his or her level of physical activity. Too often Americans eat out, consume large meals and high-fat foods, and put taste and convenience ahead of nutrition. Also, most people in the United States do not get enough physical activity.

Environment also includes the world around us—our access to places to walk and healthy foods, for example. Today, more people drive long distances to work instead of walking, live in neighborhoods without sidewalks, tend to eat out or get “take out” instead of cooking, or have vending machines with high-calorie, high-fat snacks at their workplace. Our environment often does not support healthy habits.

In addition, social factors including poverty and a lower level of education have been linked to obesity. One reason for this may be that high-calorie processed foods cost less and are easier to find and prepare than healthier foods, such as fresh vegetables and fruits. Other reasons may include inadequate access to safe recreation places or the cost of gym memberships, limiting opportunities for physical activity. However, the link between low socio-economic status and obesity has not been conclusively established, and recent research shows that obesity is also increasing among high-income groups.

Although you cannot change your genetic makeup, you can work on changing your eating habits, levels of physical activity, and other environmental factors. Try these ideas:

• Learn to choose sensible portions of
  nutritious meals that are lower in fat.
• Learn to recognize and control environmental
  cues (like inviting smells or a package of
  cookies on the counter) that make you want to eat
  when you are not hungry.
• Engage in at least 30 minutes of
  moderate-intensity physical activity (like brisk
  walking) on most, preferably all, days of the
  week.
• Take a walk instead of watching
  television.
• Eat meals and snacks at a table, not in front
  of the TV.
• Keep records of your food intake and physical
  activity.

Other Causes of Obesity

Some illnesses may lead to or are associated with weight gain or obesity. These include:

• Hypothyroidism, a condition in which the
  thyroid gland fails to produce enough thyroid
  hormone. It often results in lowered metabolic
  rate and loss of vigor.
• Cushing’s syndrome, a hormonal disorder
  caused by prolonged exposure of the body’s
  tissues to high levels of the hormone cortisol.
  Symptoms vary, but most people have upper body
  obesity, rounded face, increased fat around the
  neck, and thinning arms and legs.
• Polycystic ovary syndrome, a condition
  characterized by high levels of androgens (male
  hormone), irregular or missed menstrual cycles,
  and in some cases, multiple small cysts in the
  ovaries. Cysts are fluid-filled sacs.

A doctor can tell whether there are underlying medical conditions that are causing weight gain or making weight loss difficult.

Lack of sleep may also contribute to obesity. Recent studies suggest that people with sleep problems may gain weight over time. On the other hand, obesity may contribute to sleep problems due to medical conditions such as sleep apnea, where a person briefly stops breathing at multiple times during the night. You may wish to talk with
your health care provider if you have difficulty sleeping.

Certain drugs such as steroids, some antidepressants, and some medications for psychiatric conditions or seizure disorders may cause weight gain. These drugs may slow the rate at which the body burns calories, stimulate appetite,
or cause the body to hold on to extra water. Be sure your doctor knows all the medications you are taking (including over-the-counter medications and dietary supplements). He or she may recommend a different medication that has less effect on weight gain.

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What are the Consequences of Obesity?

Health Risks

Obesity is more than a cosmetic problem. Many serious medical conditions have been linked to obesity, including
type 2 diabetes, heart disease, high blood pressure, and stroke. Obesity is also linked to higher rates of certain types of cancer. Men who are obese are more likely than no-nobese men to develop cancer of the colon, rectum, or prostate.

Women who are obese are more likely than non-obese women to develop cancer of the gallbladder, uterus,cervix, or ovaries. Esophageal cancer has also been associated with obesity.

Other Diseases and Health Problems Linked to Obesity Include:

• Gallbladder disease and
  gallstones.
• Fatty liver disease (also called
  nonalcoholic steatohepatitis or NASH).
• Gastroesophageal reflux, or what is
  sometimes called GERD. This problem occurs when
  the lower esophageal sphincter does not close
  properly and stomach contents leak
  back—or reflux—into the
  esophagus.
• Osteoarthritis, a disease in which the
  joints deteriorate. This is possibly the result
  of excess weight on the joints.
• Gout, another disease
  affecting the joints.
• Pulmonary (breathing)
  problems, including sleep apnea, which causes a
  person to stop breathing for a short time
  during sleep.
• Reproductive problems in
  women, including menstrual irregularities and
  infertility.

Health care providers generally agree that the more obese a person is, the more likely he or she is to develop
health problems.

Psychological and Social Effects

Emotional suffering may be one of the most painful parts of obesity. American society emphasizes physical
appearance and often equates attractiveness with slimness, especially for women. Such messages make overweight people feel unattractive.

Many people think that individuals with obesity are gluttonous, lazy, or both. This is not true. As a result, people who are obese often face prejudice or discrimination in the job market, at school, and in social situations. Feelings of rejection, shame, or depression may occur.

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Who Should Lose Weight?

Health care providers generally agree that people who have a BMI of 30 or greater can improve their health
through weight loss.

This is especially true for people with a BMI of 40 or greater, who are considered extremely obese.

Preventing additional weight gain is recommended if you have a BMI between 25 and 29.9, unless you have other risk
factors for obesity-related diseases. Obesity experts recommend you try to lose weight if you have two or more of the following:

• Family history of certain chronic diseases.
  If you have close relatives who have had heart disease or diabetes, you are more likely to develop theseproblems if you are obese.
• Preexisting medical conditions
  High blood pressure, high LDL cholesterol levels, low HDL cholesterol levels, high triglycerides, and high blood glucose are all
  warning signs of some obesity-associated diseases.
• Large waist circumference.
  Men who have waist circumferences greater than 40 inches, and women who have waist circumferences greater than 35 inches, are at higher risk of diabetes, dyslipidemia (abnormal amounts of fat in the blood), high blood pressure, and heart disease.

Fortunately, a weight loss of 5 to 10 percent of your initial body weight can do much to improve health by lowering blood pressure and other risk factors for obesity-related diseases. In addition, research shows that a 5- to
7-percent weight loss brought about by moderate diet and exercise can delay or possibly prevent type 2 diabetes in people at high risk for the disease. In a recent study, participants who were overweight and had pre-diabetes—a condition in which a person’s blood glucose level is higher than normal, but not high enough to be classified as diabetes—were able to delay or prevent the onset of type 2 diabetes by adopting a low-fat, low-calorie diet and
exercising for 30 minutes a day, 5 days a week.For more information about pre-diabetes and
diabetes, visit www.diabetes.niddk.nih.gov.

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How is Obesity Treated?

The method of treatment depends on your level of obesity, overall health condition, and readiness to lose weight. Treatment may include a combination of diet, exercise, behavior modification, and sometimes weight-loss drugs. In
some cases of extreme obesity, bariatric surgery may be recommended.

Remember, weight control is a life-long effort, and having realistic expectations about weight loss is
an important consideration. Eating a healthful diet and getting at least 30 minutes of moderate-intensity physical activity on most, preferably all, days of the week have important health benefits. Sixty minutes of physical activity
a day may be required to prevent gradual weight gain in adulthood. Previously overweight and obese individuals are encouraged to get 60 to 90 minutes of exercise a day to sustain weight loss.

Although most adults do not need to see their healthcare professional before prednisone starting a moderate-intensity physical activity program, men older than 40 years and women older than 50 years who plan a vigorous program or who have either chronic disease or risk factors for chronic illnesses should speak with their health care provider before starting a physical activity program.

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Additional Reading

National Institute of Diabetes and
Digestive and Kidney Diseases. Strategic Plan
for NIH Obesity Research. U.S. Department of
Health and Human Services (DHHS); NIH. NIH
Publication No. 04-5493. 2004.

National Heart, Lung, and Blood Institute.
Clinical Guidelines on the Identification,
Evaluation, and Treatment of Overweight and Obesity
in Adults. DHHS; NIH. NIH Publication No.
98-4083. 1998.

National Task Force on Prevention and Treatment
of Obesity. Overweight, obesity, and health risk.
Archives of Internal Medicine.
160(7):898-904. 2000.

Partnership for Healthy Weight Management.
Weight Loss: Finding a Weight Loss Program that
Works for You.

Website:

www.consumer.gov/weightloss/brochures.htm.
2000.

U.S. Department of Agriculture and DHHS.
Finding Your Way to a Healthier You: Based on
the “Dietary Guidelines for
Americans.” Phone: 1-888-878-3256.
Website: www.healthierus.gov/dietaryguidelines.

2005.

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