Obesity

Answer 1

Definition

Obesity is a term used to describe body weight that is much greater than what is healthy. If you are obese, you also have a much higher amount of body fat than is healthy or desirable.

Adults with a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) between 25 kg/m2 and 30 kg/m2 are considered overweight.

Adults with a BMI greater than or equal to 30 kg/m2 are considered obese.

Anyone who is more than 100 pounds overweight or who has a BMI greater than or equal to 40 kg/m2 is considered morbidly obese.

Alternative Names

Morbid obesity; Fat - obese

Causes, incidence, and risk factors

Taking in more calories than you burn leads to being overweight and, eventually, obesity. The body stores unused calories as fat. Obesity can be the result of:

• Eating more food than your body can use
• Drinking too much alcohol
• Not getting enough exercise

An underactive thyroid (hypothyroidism) may lead to 5 - 10 pounds of weight gain. Some antidepressants and antipsychotic medicines may also contribute to weight gain and obesity. Genetic factors play some part in the development of obesity -- children of obese parents are 10 times more likely to be obese than children with parents of normal weight.

People who are at higher risk for obesity include:

• Lower income groups
• Former smokers
• People with chronic mental illness
• People with disabilities
• People with a sedentary lifestyle

Signs and tests

The health care provider will perform a physical exam and ask questions about your medical history, eating habits, and exercise routine.

Skin fold measurements may be taken to check your body fat percentage.

Blood tests may be done to look for thyroid or endocrine problems, which could lead to weight gain.

Treatment

Regular exercise and a healthy diet are crucial when it comes to controlling your weight. Although there are many programs advertised to help you lose weight, the only method proven safe over the long-term is to burn more calories than you consume.

Exercising and eating right must become as much a part of your routine as bathing and brushing your teeth. Unless you are convinced of the benefits, you will not succeed.

DIET

Most people can lose weight by eating a healthier diet and exercising more. Even modest weight loss can improve your health. Sticking to a weight reduction program is not easy. You will need a lot of support from family and friends.

When dieting, your main goal should be to learn new, healthy ways of eating and make them a part of your everyday routine. Learn to read the nutrition labels and ingredients of all the foods you eat.

Work with your health care provider and dietitian to set realistic, safe daily calorie counts that help you lose weight while staying healthy. Remember that if you drop pounds slowly and steadily, you are more likely to keep them off. Your dietitian can teach you about healthy food choices, portion sizes, and new ways to prepare food.

Extreme diets (fewer than 1,100 calories per day) are not thought to be safe or to work very well.

• These types of diets often do not contain enough vitamins and minerals.
• People who are on these diets may experience symptoms such as fatigue, feeling cold most of the time, hair loss, or dizziness.
• There is a risk for gallbladder stones, changes in menstrual periods, and rarely, dangerous heart rhythms.
• Most people who lose weight this way return to overeating and become obese again.

See also: Sweeteners

Other changes can have an impact on your weight loss success:

• Eat only at the table. No snacking in front of the TV, in bed, while driving, or while standing in front of the open refrigerator.
• Learn about appropriate portion sizes.
• Choose low-calorie snacks, such as raw vegetables.
• Learn new ways to manage stress, rather than snacking. Examples may be meditation, yoga, or exercise.
• Keep a diet and exercise journal. This may help you identify overeating triggers in your life.
• If you are depressed, seek medical treatment rather than eating excessively to help cope with your depression.
• Find a support group or consider psychotherapy to help you achieve your weight loss goal.

EXERCISE

To lose weight, you must burn more calories than you eat. Exercise is a key way to do this. Walking a mile a day for 30 days will help you burn off 1 pound of fat, as long as you don't eat more than usual.

If you have not been active, start slowly and build up over weeks or even months. Walking can be a good exercise to start with. Talk to your health care provider before starting.

Every week, increase the amount of time you spend doing the activity. Do it more often or add a second activity. You can increase the speed or difficulty of the activity (for example, by going up hills).

All adults should get 2 1/2 hours of aerobic exercise each week. Spread the exercise out over the week. Exercise for at least 10 minutes at a time.

Find ways to increase your activity level very day.

• Walk instead of driving. If you have to drive, park several blocks away from your destination.
• Climb stairs instead of using an elevator or escalator.
• Do other house activities, such as gardening.

In addition to burning off extra calories, exercise will also:

• Lift your mood and help with anxiety
• Make your bones stronger
• Reduce your chance of having a heart attack or stroke
• Help you manage high blood pressure and cholesterol

MEDICATIONS AND HERBAL REMEDIES

There are many over-the-counter diet products. These include herbal remedies. Most of these products do not work and some can be dangerous. Before using an over-the-counter or herbal diet remedy, talk to your health care provider.

Several prescription weight loss drugs are available, including sibutramine (Meridia) and orlistat (Xenical). Ask your health care provider if these are right for you.

Usually, you can lose between 5 and 10 pounds by taking these drugs. People usually regain the weight when they stop taking the medication, unless they have made lasting lifestyle changes.

SURGERY

Weight-loss surgery may be done to help you lose weight if you are very obese and have not been able to lose weight with diet and exercise.

Surgery alone is not the answer for weight loss. It can train you to eat less, but you still have to do much of the work. You must be committed to diet and exercise after the surgery.Talk to your doctor to learn if this is a good option for you.

The two most common weight-loss surgeries are:

• Laparoscopic gastric banding -- the surgeon places a band around the upper part of your stomach, creating a small pouch to hold food. The band helps you limit how much food you eat by making you feel full after eating small amounts.
• Gastric bypass surgery -- helps you lose weight by changing how your stomach and small intestine handle the food you eat. After the surgery, you will not be able to eat as much as before, and your body will not absorb all the calories and other nutrients from the food you eat.

You may have complications from these surgeries. One problem some people have is throwing up if they eat more than their new small stomach can hold.

Support Groups

Many people find it easier to follow a diet and exercise program if they join a group of people with similar problems.

See: Eating disorders - support group

Complications

Obesity is a significant health threat. The extra weight puts added stress on all parts of your body.

Medical problems commonly resulting from untreated obesity and morbid obesity include:

• Type 2 diabetesand metabolic syndrome
• High blood pressure, heart disease, and stroke
• Obstructive sleep apnea and other sleep disorders
• Certain cancers, including breast and colon cancer
• Depression
• Osteoarthritis

Extreme obesity can lead to a gradual decrease in the level of oxygen in your blood, a condition called hypoxemia. Decreased blood oxygen levels and sleep apnea may cause a person to feel sleepy during the day. These conditions may also lead to high blood pressure and pulmonary hypertension. In extreme cases, especially when left untreated, this can lead to right-sided heart failure and ultimately death.

Calling your health care provider

Schedule an appointment with your health care provider if you or your child is obese or gaining weight at an extremely rapid rate. Remember that catching the problem early is much simpler than trying to fix it after the person has gained an excessive amount of weight.

References

Leslie D, Kellogg TA, Ikramuddin S. Bariatric surgery primer for the internist: keys to the surgical consultation. Med Clin North Am. 2007;91:353-381.

Richards WO, Schirmer BD. Morbid Obesity. In: Townsend CM Jr., Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 17.

Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA. 2007;297(9):969-977.

Position of the American Dietetic Association: Weight Management. J Am Diet Assoc. 2009;109:330-346.

Thompson WG, Cook DA, Clark MM, et al. Treatment of obesity. Mayo Clin Proc. 2007;82(1):93-101

Svetke, LP, Stevens VJ, Brantley PJ, et al. Comparison of strategies for sustaining weight loss: the weight loss maintenance randomized controlled trial. JAMA. 2008;299(10):1139-48.

Kaplan LM, Klein S, Boden G, Brenner DA, Gostout CJ, Lavine JE, Popkin BM, Schirmer BD, Seeley RJ, Yanovski SZ, Cominelli F. Report of the American Gastroenterological Association (AGA) Institute Obesity Task Force. Gastroenterology. 2007;132(6):2272-5.

Answer 2

Definition

Obesity means having too much body fat. It is not the same as being overweight, which means weighing too much. A person may be overweight from extra muscle, bone, or water, as well as from having too much fat.

Both terms mean that a person's weight is higher than what is thought to be healthy for his or her height.

Alternative Names

Morbid obesity; Fat - obese

Causes, incidence, and risk factors

Taking in more calories than you burn can lead to obesity because the body stores unused calories as fat. Obesity can be caused by:

• Eating more food than your body can use
• Drinking too much alcohol
• Not getting enough exercise

Many obese people who lose large amounts of weight and gain it back think it is their fault. They blame themselves for not having the willpower to keep the weight off. Many people regain more weight than they lost.

Today, we know that biology is a big reason why some people cannot keep the weight off. Some people who live in the same place and eat the same foods become obese, while others do not. Our bodies have a complex system to help keep our weight at a healthy level. In some people, this system does not work normally.

Other factors that affect weight include:

• The way we eat when we are children can affect the way we eat as adults. The way we eat over many years becomes a habit. It affects what we eat, when we eat, and how much we eat.
• We are surrounded by things that make it easy to overeat and hard to stay active:
  • Many people do not have time to plan and make healthy meals.
  • More people today work desk jobs compared to more active jobs in the past.
  • People with less free time have less time to exercise.

The term "eating disorder" means a group of medical conditions that have an unhealthy focus on eating, dieting, losing or gaining weight, and body image. A person may be obese, follow an unhealthy diet, and have an eating disorder all at the same time.

Sometimes, medical problems or treatments cause weight gain, including:

• Underactive thyroid gland (hypothyroidism)
• Medicines such as Birth Control pills, antidepressants, and antipsychotics

Other things that can cause weight gain are:

• Quitting smoking. Most people who quit smoking gain 4 - 10 pounds in the first 6 months after quitting. Some people gain as much as 25 - 30 pounds.
• Stress, anxiety, feeling sad, or not sleeping well
• For women:
  • Menopause -- women may gain 12-15 pounds during menopause
  • Not losing the weight they gained during pregnancy

Signs and tests

The health care provider will perform a physical exam and ask questions about your medical history, eating habits, and exercise routine.

The two most common ways to measure health risks from your weight are:

• Body mass index(BMI)
• Waist circumference (your waist measurement in inches)

BMI is measured using height and weight. You and your health care provider can use your BMI to estimate how much body fat you have.

Your waist measurement is another way to estimate how much body fat you have. Extra weight around your middle or stomach area increases your risk for type 2 diabetes, Heart disease, and stroke. People with "apple-shaped" bodies (meaning their waist is bigger than their hips) also have an increased risk for these diseases.

Skin fold measurements may be taken to check your body fat percentage.

Blood tests may be done to look for thyroid or hormone problems that could lead to weight gain.

Treatment

CHANGING YOUR LIFESTYLE

An active lifestyle and regular exercise, along with healthy eating, is the best way to lose weight. Even modest weight loss can improve your health. You will need a lot of support from family and friends.

When dieting, your main goal should be to learn new, healthy ways of eatingand make them a part of your daily routine.

Many people find it hard to change their eating habits and behaviors. You may have practiced some habits for so long that you may not even know they are unhealthy, or you do them without thinking. You need to be motivated to make lifestyle changes. Make the behavior change part of your life over the long term. Know that it takes time to make and keep a change in your lifestyle.

Work with your health care provider and dietitian to set realistic, safe daily calorie counts that help you lose weight while staying healthy. Remember that if you drop pounds slowly and steadily, you are more likely to keep them off. Your dietitian can teach you about:

• Healthy food choices
• Healthy snacks
• Sweetened drinks
• Portion sizes
• How to read the nutrition labels
• New ways to prepare food

Extreme diets (fewer than 1,100 calories per day) are not thought to be safe or to work very well. These types of diets often do not contain enough vitamins and minerals. Most people who lose weight this way return to overeating and become obese again.

Learn new ways to manage stress, rather than snacking. Examples may be meditation, yoga, or exercise. If you are depressed or stressed a lot, talk to your health care provider.

MEDICATIONS AND HERBAL REMEDIES

You may see ads for supplements and herbal remedies that claim they will help you lose weight. Many of these claims are not true, and some of these supplements can have serious side effects. Talk to your health care provider before using them.

Several prescription weight loss drugs are available. Most people lose between 5 and 10 pounds by taking these drugs. Most people also regain the weight when they stop taking the medicine, unless they have made lasting lifestyle changes, such as exercising and cutting unhealthy foods from their diet.

SURGERY

Bariatric surgery can reduce the risk of disease in people with severe obesity. These risks include:

• Arthritis
• Diabetes
• Heart disease
• High blood pressure
• Sleep apnea
• Some cancers
• Stroke

Surgery may help people who have been very obese for 5 years or more and have not lost weight from other treatments, such as diet, exercise, or medicine.

Surgery alone is not the answer for weight loss. It can train you to eat less, but you still have to do much of the work. You must be committed to diet and exercise after the surgery. Talk to your doctor to learn if this is a good option for you.

The two most common weight-loss surgeries are:

• Laparoscopic gastric banding
• Gastric bypass surgery

You may have complications from these surgeries. One problem some people have is throwing up if they eat more than their new small stomach can hold.

Support Groups

Many people find it easier to follow a diet and exercise program if they join a group of people with similar problems.

See: Eating disorders - support group

Complications

Obesity is a major health threat. The extra weight puts added stress on every part of your body.

People with obesity are at risk for these health problems:

• Bone and joint problems -- extra weight puts strain on the bones and joints. This can lead toosteoarthritis, a disease that causes joint pain and stiffness.
• Gallstones and liver problems
• Heart attack from coronary heart disease, congestive heart failure, and stroke
• High blood cholesterol and triglycerides (dislipidemia or high blood fats)
• High blood pressure (hypertension)
• High blood sugar (glucose) or diabetes
• Stopping breathing during sleep (sleep apnea). This can cause daytime fatigue or sleepiness, poor attention, and problems at work.

References

Garb J, Welch G, Zagarins S, Kuhn J, Romanelli J. Bariatric surgery for the treatment of morbid obesity: a meta-analysis of weight loss outcomes for laparoscopic adjustable gastric banding an dlaparoscopic gastric bypass. Obes Surg. 2009;19:1447-1455.

Sacks FM, Bray GA, Carey VJ, Smith SR, Ryan DH, Anton SD, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360:859-873.

Dale KS, McAuley KA, Taylor RW, Williams SM, Farmer VL, Hansen P, et al. Determining optimal approaches for weight maintenance: a randomized controlled trial. CMAJ. 2009;180:E39-E46.

United States Department of Agriculture. Dietary Guidelines for Americans, 2010. Accessed June 5, 2011.

Richards WO, Schirmer BD. Morbid obesity. In: Townsend CM Jr., Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 17.

Seagle HM, Strain GW, Makris A, Reeves RS; American Dietetic Association. Position of the American Dietetic Association: weight management. J Am Diet Assoc. 2009;109:330-346.

Svetke LP, Stevens VJ, Brantley PJ, et al. Comparison of strategies for sustaining weight loss: the weight loss maintenance randomized controlled trial. JAMA. 2008;299:1139-1148.

Kaplan LM, Klein S, Boden G, et al. Report of the American Gastroenterological Association (AGA) Institute Obesity Task Force. Gastroenterology. 2007;132:2272-2275.

Reviewed By

Review Date: 07/11/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.