Obesity

Obesity is more than just being overweight. It is not a question of needing to lose a few pounds. (Read about "Losing Weight") Obesity is instead defined as having an excessively high amount of body fat. Another measure of obesity is body mass index. (Read about "Body Mass Index") This is a ratio of weight to height. The Centers for Disease Control and Prevention (CDC) say individuals with a BMI greater than or equal to 30 are considered obese. A BMI between 25 and 30 is considered overweight.

You can use our calculator to determine your BMI. To check the results, or if the calculator won't work on your computer, just refer to this table.

The number of Americans considered obese is on the rise. CDC says the number has nearly doubled from approximately 15 percent in 1980 to nearly 30 percent in recent years. The American Society for Bariatric Surgery (ASBS) says morbid obesity (which is defined by ASBS as a BMI of 40 or more or 100 pounds overweight) is a major public health risk, affecting over four million Americans.

Health risks

Obesity increases the risks that you will develop any number of health problems. CDC says they include:

• high blood pressure or hypertension (Read about "Hypertension: High Blood Pressure")
• high blood cholesterol (Read about "Cholesterol")
• type 2 (non-insulin dependent) diabetes (Read about "Diabetes")
• insulin resistance, glucose intolerance (Read about insulin resistance in "Metabolic Syndrome")
• coronary heart disease (Read about "Coronary Heart Disease")
• congestive heart failure (Read about "Congestive Heart Failure")
• stroke (Read about "Stroke")
• gout (Read about "Gout")
• osteoarthritis (Read about "Osteoarthritis")
• obstructive sleep apnea and respiratory problems (Read about sleep apnea in "A Good Nights Sleep" and about respiratory problems in "Respiratory System")
• fatty liver disease (Read about "The Liver")
• some types of cancer such as endometrial, breast, prostate, and colon (Read about "Uterine Cancer" "Breast Cancer" "The Prostate" "Colorectal Cancer")
• complications of pregnancy (Read about "Healthy Pregnancy")
• poor female reproductive health such as menstrual irregularities, infertility, irregular ovulation (Read about "Menstrual Disorders" "Infertility")
• bladder control problems such as stress incontinence (Read about "The Urinary System" "Incontinence")
• psychological disorders such as depression, eating disorders, distorted body image, and low self esteem (Read about "Depressive Illnesses" "Eating Disorders")

Many obese people need a combination of diet, exercise and sometimes weight-loss drugs. In some cases of severe obesity, gastrointestinal surgery may be recommended. Psychological counseling may also be needed, for example, if obesity is associated with an eating disorder such as binge eating. (Read about "Eating Disorders")

Diet and exercise

The key to losing weight is to take in fewer calories than you use up - in other words to eat less and exercise more. Sounds easy, but as anyone who's tried to lose weight knows, it's not that simple. There are some things you can do to make it easier.

• Arm yourself with knowledge. Learn about burning calories and food labels (Read about "Burning Calories" "Food Labels"), about starting and sticking with an exercise program (Read about "Getting Started on Fitness" "Staying With It"), and other topics related to losing weight. (Read about "Dietary Guidelines")
• Enlist the help of family and friends.
• Join a support group.

NIDDK says you should also check with your doctor, especially if you have more than 20 pounds to lose. That's because the risk for developing gallstones (Read about "Gallstones") increases with quick weight loss or a large weight loss.

Weight loss programs

Some people can change their lifestyle on their own. But for many obese people, there's a need for a more formal program. If you decide to enroll in such a program, NIDDK says to look for one with:

• healthy eating plans that reduce calories but do not rule out specific foods or food groups
• regular physical activity and/or exercise instruction
• tips on healthy behavior changes that also consider your cultural needs
• slow and steady weight loss of about three-quarters to 2 pounds per week and not more than 3 pounds per week (weight loss may be faster at the start of a program)
• medical care if you are planning to lose weight by following a special formula diet, such as a very-low-calorie diet
• a plan to keep the weight off after you have lost it

Cost is another issue to consider. Some plans have sign-up fees and/or weekly charges. You should also investigate the training and qualifications of staff. In addition, NIDDK says that if you have medical problems, or if you are severely overweight, you should look for programs run by trained health professionals. They can monitor you for possible side effects of weight loss and talk to your doctor if necessary.

Surgery

Sometimes obesity cannot be treated by diet and exercise alone. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says gastrointestinal surgery or bariatric surgery (Read about "Bariatric Surgery") can be the best option for people who are severely obese and cannot lose weight by traditional means or who suffer from serious obesity-related health problems. By severely obese, NIDDK means having a BMI of over 40, or being at least 80-100 pounds overweight.

Surgery basically works by reducing the amount of food absorbed during the digestive process. (Read about "Digestive System") Normally, digestion starts as we chew and swallow our food, and the food moves down the esophagus to the stomach. The stomach can hold about 3 pints of food at one time. When the stomach contents move to the duodenum, the first segment of the small intestine, digestion speeds up. Most of the iron and calcium in the foods we eat is absorbed in the duodenum. The jejunum and ileum, the remaining two segments of the nearly 20 feet of small intestine, complete the absorption of almost all calories and nutrients. The food particles that cannot be digested in the small intestine are stored in the large intestine until eliminated.

Bariatric surgery alters this process. There are several types of surgery, each with its own benefits and risks. ASBS says the surgeries fall into different categories:

• Restrictive - These types of surgery restrict the amount of food that the stomach can hold, using bands and/or staples. As a result, people lose the ability to eat large amounts of food at one time; otherwise, they experience discomfort or nausea. NIDDK says the success of such surgery depends on the patient's willingness to adopt a long-term plan of healthy eating and regular physical activity.
• Malabsorptive - These types of bariatric surgery restrict both food intake and the amount of calories and nutrients the body absorbs. This type of surgery can lead to greater weight loss, but also carries a greater risk for nutritional deficiencies. Patients undergoing a malabsorptive type of surgery can often require close monitoring and life-long use of special foods, supplements and medications.
• Combined Restrictive/Malabsorptive Operations - Combined operations are the most common bariatric procedures, according to NIDDK. They restrict both food intake and the amount of calories and nutrients the body absorbs.

Surgery to produce weight loss is a serious undertaking. Side effects can include nausea, dehydration and constipation. (Read about "Dehydration" "Constipation") Rapid gastric emptying or dumping syndrome is also common, especially if you do not follow your doctor's diet directions. (Read about "Rapid Gastric Emptying") Anyone thinking about surgery should understand what the operation involves. Patients and physicians should carefully consider the following benefits and risks. It's also important to note that success is possible only with maximum cooperation and commitment to behavioral change and lifelong medical follow-up. (Read about "Learn About Your Procedure")

Medications

NIDDK says weight-loss medications may be appropriate for carefully selected patients who are at significant medical risk because of their obesity. They are not recommended for people who are only mildly overweight unless they have health problems that are made worse by their weight. These medications should not be used only to improve appearance.

Most available weight-loss medications promote weight loss by decreasing appetite and/or increasing the feeling of being full, by altering brain chemicals that affect mood and appetite. (Read about "The Brain") People respond differently to weight-loss medications, and some people experience more weight loss than others. NIDDK says the average weight loss is 5-22 pounds above what would be expected without using medications, and that maximum weight loss usually occurs within 6 months of starting medication treatment.

If medications are used, they are not a substitute for healthier eating habits, but should be combined with physical activity and improved diet to lose and maintain weight successfully over the long term. (Read about "Medicine Safety")