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.
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:
Waist circumference (your waist measurement in inches)
BMI is calculated 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. However, these tests are usually normal.
CHANGING YOUR LIFESTYLE
An active lifestyle and plenty of exercise, along with healthy eating, is the safest 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 eating and 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:
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. Some of these supplements can have serious side effects. Talk to your health care provider before using them.
You can discuss weight loss drugs with your doctor. 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.
Bariatric surgery can reduce the risk of disease in people with severe obesity. These risks include:
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 surgery. Talk to your doctor to learn if this is a good option for you.
Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patietns with diabetes. N Engl J Med. 2012:Epub March 26.
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.
United States Department of Agriculture. Dietary Guidelines for Americans, 2010. Accessed April 21, 2012.
Wadden TA, Volger S, Sarwer DB, et al. A two year randomized trial of obesity treatment in primary care practice. N Engl J Med. 2011;365:1969-1979
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.