Being overweight or obese puts you at risk for a number of diseases, including heart disease, diabetes, high blood pressure, stroke, gallbladder disease, osteoarthritis, and respiratory disorders. The risk of developing these diseases is even higher when weight is concentrated near the waist.

Obesity is an increasing problem. According to the National Institutes of Health, 60% of American adults are overweight and 25% are considered obese, while about 25% of American children are overweight or obese. And the numbers are rising. Taking weight off, and keeping it off, is difficult. Many people who lose weight later gain back some or all of the excess pounds.

Despite growing research on obesity, there are no medications, herbs, or supplements that can help you lose a significant amount of weight, and all have some side effects. The only way to lose weight is to reduce the amount of calories you eat and increase the time and intensity of your exercise. These actions have many health benefits in addition to helping you lose weight.

Obesity is usually determined by body mass index, or BMI, using a formula that calculates a ratio of your height to your weight.

• BMI 25 - 29.9 (overweight)
• BMI 30 and above (obese)

A high waist to hip ratio (indicating that fat is centered around the waist) increases the risk for developing serious, even life-threatening conditions associated with obesity. Generally, for men a ratio of .90 or less is considered safe. For women, .80 or less is considered safe.

Conditions that may accompany obesity include:

• High cholesterol (including high triglyceride levels)
• Diabetes
• High blood pressure
• Sleep apnea (episodes when a person stops breathing while asleep)
• Osteoarthritis
• Gallstones

A number of factors contribute to obesity.

• Diet: Eating high-fat, high-calorie foods causes weight gain.
• Lack of exercise: Sedentary people don't burn as many calories as active people.
• Genetics: Your genes may influence how much fat your body stores and where it store it, although genes alone do not mean you will be obese.
• Age: People gain weight as they get older, because they tend to be less active and to lose muscle mass.
• Psychological issues: Some people overeat when they are upset or stressed.
• Medications: Some drugs, such as corticosteroids, blood pressure medication, and tricyclic antidepressants, can cause you to gain weight.
• Medical problems: Rarely, obesity is due to a medical problem such as Cushing's syndrome (where the adrenal glands produce too much hormone) or hypothyroidism (where the thyroid gland doesn't produce enough hormone). Conditions such as osteoarthritis cause people to be less active, which can lead to weight gain.

The following factors may increase an individual's risk for becoming obese:

• Living in an industrialized country, especially the United States
• Having family members who are overweight or obese
• Not being physically active
• Overeating
• Eating a high-fat diet
• Taking certain prescription medications (see "Causes")
• Having a hormone disorder, such as Cushing's syndrome or hypothyroidism (underactive thyroid)
• Being emotionally stressed (from the death of a loved one, for example), which may cause a person to overeat

The best way to prevent obesity and maintain a normal weight is to eat a healthy diet and exercise daily. Keeping a food and exercise journal, where you record what you eat and how long you exercise, is an excellent way to get started.

Organizations such as the American Diabetes Association, the American Heart Association, and the American Dietetic Association have developed guidelines that promote weight loss and healthy eating. These guidelines recommend that no more than 30% of a person's total calorie intake should come from fats. Overall, you should eat a wide variety of foods, especially fruits and vegetables, in order to stay healthy and maintain proper weight.

Many studies show that exercise -- from moderate to intense -- helps prevent obesity. The Centers for Disease Control and Prevention and the American Academy of Sports Medicine recommend at least 30 minutes of moderate aerobic activity (such as a brisk walk) at least 5 days a week. You don't have to exercise for 30 minutes at a time; 10 minutes, done three times a day, is also effective. In fact, any exercise -- from taking the stairs to cleaning the house or working in the garden -- is beneficial.

Health care practitioners use BMI to diagnose obesity. To determine BMI, weight in kilograms is divided by height in meters, squared. You can find online BMI calculators that do the math for you. As previously noted in the "Signs and Symptoms" section, the following BMI ranges are most often used as indications that a person is overweight or obese:

• BMI 25 - 29.9 (overweight)
• BMI 30 and above (obese)

Your doctor may also measure your blood pressure and percentage of body fat, and may order blood tests to check cholesterol levels and determine how well your thyroid is functioning.

Losing weight -- and then maintaining a healthy weight -- involves a combination of diet, exercise, and other lifestyle modifications. Although some medications, herbs, and supplements may help you lose a little weight, you still must eat fewer calories and exercise more to see any real effect. For severe obesity, bariatric surgery (which physically restricts the amount of food a person can eat) may be an option.

Lifestyle

To lose weight, you must eat fewer calories and increase your physical activity to burn more calories. The key to losing and keeping off weight is to set realistic weight loss goals that are achievable. The changes you make to your eating and exercise habits will need to last throughout your life.

Exercise

Exercise can help you lose weight, especially in the first six months, and to maintain your desired weight in the long-term. Exercise not only contributes to weight loss, it also decreases abdominal fat and increases heart health, lowers blood pressure, and helps keep blood sugar in check.

If you are not used to exercising, start slowly and build up to the goal of 30 minutes a day for at least 5 days a week. An ideal exercise program includes aerobic activity (walking, swimming, biking), strength training (lifting weights), and flexibility (stretching). If you are severely obese or have other medical problems, talk to your doctor before starting a new exercise program.

You may be sore at first. Some muscle soreness is normal. However, if you experience pain that lasts more than 2 hours after your workout, see your doctor before continuing.

Drug Therapies

Some medications help promote weight loss, but there are no drugs to cure obesity. Weight loss medications should be used in addition to diet, exercise, and other lifestyle modifications. Many of these drugs are available by prescription only and some have serious side effects.

Over-the-counter Medications

Orlistat (Alli) -- The FDA has approved Alli as the only over-the-counter weight loss drug. It reduces the amount of fat your body can absorb from foods. Side effects include oily stools, flatulence, and diarrhea. Alli also blocks you body from absorbing some vitamins and nutrients, so you should take a multivitamin daily.

Prescription Medications

• Sibutramine (Meridia) -- boosts metabolism, enhances energy level, and promotes a feeling of fullness. Side effects include dry mouth and insomnia; cannot be taken by people with a history of stroke, seizures, or heart, liver, or kidney diseases. Meridia is moderately effective; studies show that people who take Meridia lost about 10 pounds more than those who just followed a low-calorie diet.
• Orlistat (Xenical) -- reduces the absorption of fat from foods; side effects include oily stools, flatulence, and diarrhea. Recently approved for over-the-counter sale in the U.S.
• Phentermine -- suppresses appetite; serious potential side effects include pulmonary hypertension and heart valve defects. Phentermine is similar to an amphetamine and should not be taken by people with high blood pressure, heart disease, glaucoma, or those taking antidepressant medications

Surgical Procedures

Bariatric or weight-loss surgery may be considered in cases where people are severely obese and lifestyle changes have not worked. Physicians carefully select individuals for surgery, and patients must undergo psychological testing and counseling. Bariatric surgery reduces the amount of food that can be taken into the stomach. People who have had bariatric surgery must be monitored by their doctor afterward to make sure they get enough essential nutrients. Procedures include:

• Roux-en Y procedure (gastric bypass) -- permanently reduces the size of the stomach; vomiting is the most common side effect
• Gastric banding -- An adjustable silicone band is placed around the stomach, decreasing the amount of food that can be eaten. The band can be adjusted or removed.

Complementary and Alternative Therapies

Diet

Diet plans are enormously popular. They range from traditional low-fat, high-carbohydrate diets to high-protein, high-fat, low-carbohydrate diets. The truth is, no specific diet works for everyone, and no diet works without the other essential components of weight loss -- exercise and stress management.

The U.S. Department of Health and Human Services says a healthy diet

• Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat dairy products
• Includes lean meats, poultry, fish, beans, eggs, and nuts
• Is low in saturated fats, trans fats, cholesterol, salt, and added sugar

Among many weight-loss plans available, the ones that generally result in a balanced diet include the Weight Watchers plan, the South Beach Diet, and the American Heart Association No Fad Diet. Beware of diets that promise quick, substantial weight loss; they often don't contain enough of the nutrients your body needs to stay healthy, and you're more likely to go off the diet and engage in binge eating, gaining the weight back. Weight loss of about 1 to 2 pounds per week is considered safe and sustainable. Before attempting any diet, it is important to consult a healthcare practitioner to determine which plan is right for you.

Nutrition and Supplements

Most evidence for using these supplements in weight loss is either scant or mixed. None of these supplements will work for significant weight loss without changes to diet and exercise habits. Talk to your healthcare provider before using these supplements.

5-Hydroxytryptophan (5-HTP) (600 - 900 mg per day) -- 5-HTP is thought to reduce hunger cravings by boosting serotonin levels in the central nervous system, which may reduce appetite and lessen food cravings. However, 5-HTP has been associated with eosinophilia myalgia syndrome (EMS), a rare and potentially fatal blood disorder, although it isn't clear whether 5-HTP actually contributes to developing the disorder. In addition, people who take antidepressants or herbs and supplements with antidepressant effects (such as St. John's wort and SAMe) should avoid 5-HTP. Talk to your doctor before taking 5-HTP.

Fiber -- may help lower insulin levels (insulin controls the amount of sugar in the blood) and help you feel fuller.

Conjugated linoleic acid (CLA) -- Preliminary human and animal studies suggest that CLA may help control weight by reducing body fat and enhancing lean body mass. However, the benefit appears to be slight, there is some question as to whether CLA can increase insulin resistance in overweight people (a precursor to developing diabetes), and studies show mixed results for weight loss.

Zinc (15 - 20 mg per day) -- may increase lean body mass and decrease or keep stable the amount of fat. The reason may be that zinc increases levels of leptin, a hormone in the body that helps you feel full.

Chitosan (1,500 mg three times per day) -- Chitosan is a fiber-like supplement made from the shells of crustaceans such as shrimp and crab. While some studies have found that chitosan (in addition to a low-calorie diet) reduces weight, it is unclear whether the supplement itself, the low-calorie diet, or a combination of both led to the weight loss. Other studies have shown mixed results.

Pyruvate (22 - 44 g per day) -- Pyruvate is a substance that occurs naturally in the body, where it is converted to lactic acid. There is some evidence that it may help reduce body fat, possibly by increasing the body's metabolic rate. Other studies show no effect.

Hydroxycitric acid (HCA) (2.5 g per day) -- This substance, extracted from the fruit Garcinia cambogia, is similar to citric acid (found in oranges and citrus fruits). In test tubes, HCA stops carbohydrates from being stored as fat, and some animal tests indicate HCA can suppress appetite. However, studies in humans show mixed results.

7-keto or 7-keto-DHEA (3-acetyl-7-oxo-dehydroeplandrosterone) (100 mg two times per day) -- 7-keto is a substance related to DHEA, a substance in the body that is the precursor to male and female hormones. DHEA has been studied as a weight-loss supplement, but results are mixed and there is some concern over DHEA's hormone-like effects on the body. One preliminary trial suggested that 7-keto may help enhance weight loss for people who are already dieting and exercising, without risk of the side effects of DHEA (7-keto is not converted to hormones in the body). However, more studies are needed to determine whether 7-keto has any real effect on weight loss. People who have had or are at risk of hormone-related cancers should not take 7-keto without their doctor's supervision.

Chromium (600 mcg per day) -- Chromium or chromium picolonate is a popular supplement among bodybuilders and those trying to lose weight and build more lean muscle mass. However, results from scientific studies have been mixed, and its effects are small compared to those of exercise and a well-balanced diet. Chromium may improve blood sugar (also a risk factor for heart disease), particularly in those with diabetes and glucose intolerance, but should not be taken for that purpose without a doctor's supervision. In addition, large doses of chromium can cause kidney damage.

Glucomannan (1 g three times per day, 1 hour before each meal) -- Glucomannan is a kind of insoluble fiber that appears to reduce blood sugar levels and may help to promote weigh loss. People with diabetes should not take glucomannan without their doctor's supervision.

Herbs

Psyllium (Plantaginis ovatae) -- Psyllium, a kind of soluble fiber, may reduce hunger cravings by making you feel full. For this reasons, incorporating psyllium and other sources of fiber into your diet may aid weight loss.

Green tea (Camellia sinensis) -- Researchers have theorized that polyphenols (chemical substances found in plants that have antioxidant properties, protecting cells in the body against damage) found in green tea extract may boost metabolism and help burn fat. However, studies have shown mixed results so far. In addition, the extracts used in the studies have contained caffeine, which could be responsible for increasing metabolism and promoting weight loss. If you are sensitive to caffeine or have anxiety or heart problems, you may want to limit how much green tea you consume.

Guggul (Commiphora mukal, 25 mg of guggulsterones three times per day) -- a common ingredient in several Ayurvedic medicines used to treat obesity. Studies suggest that overweight people who take these Ayurvedic remedies lose slightly more weight compared to those who do not take them. Guggul can cause mild diarrhea and nausea, and may interact with the following medications: blood-thinning drugs (anticoagulants), birth control pills, thyroid hormone, tamoxifen, and estrogens. People who take these medications should not take guggul. In addition, people who have or have had hormone-sensitive cancers (breast, ovarian, or prostate cancer) should not take guggul.

Cayenne or capsaicin (Capsicum frutescens, 6 - 10 g per meal) -- Preliminary evidence indicates that capsaicin (the substance that makes chili peppers taste hot) may reduce hunger and help the body burn fat, particularly when eating a high-fat diet. More research is needed to confirm these early findings, however.

Hoodia (Hoodia gordonii) -- A number of media reports on hoodia have suggested it could be an effective weight-loss supplement. However, the only evidence that exists is a single, unpublished study funded by the manufacturer of the supplement, so no one knows whether hoodia works or even whether it is safe. In addition, news reports now suggest that most hoodia supplements on the market today contain little if any of the actual herb. Until more research is done and trusted sources exist to provide the herb, hoodia is best avoided.

Homeopathy

Few studies have examined the effectiveness of specific homeopathic remedies, and there is no single or combination homeopathic remedy that will help all people lose weight. However, individualized homeopathic therapy can be designed to aid weight loss by addressing metabolism, digestion, and elimination. Before prescribing a remedy, homeopaths take into account a person's constitutional type -- your physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate remedy for an individual.

Acupuncture

Many studies have found both acupuncture and acupressure can improve weight loss slightly. Acupuncture is believed to promote weight loss by stimulating points on the body that boost serotonin levels. (Elevated serotonin levels are thought to suppress appetite.) One well-designed study found that people who received electrical acupuncture of the ear (auricular acupuncture) reduced their appetite.

Cognitive Behavioral Therapy

Besides changing diet and exercise habits, successful weight loss often requires additional behavioral adjustments to keep the weight off. That might include setting reasonable weekly or monthly goals -- how much exercise or how much weight loss is desired, for instance -- and finding ways to reward yourself for successes that don't involve food. Working with both a dietician and a behavioral specialist can help you put these practices into play.

It also helps to reduce the stress that leads to overeating by practicing relaxation exercises, such as yoga, meditation, or tai chi.

Finally, it is hard to lose weight without support. Support groups such as Overeaters Anonymous or Weight Watchers can help you stay focused on your goals and allow members to share success and encourage each other.

Hypnosis

Although studies are mixed, some evidence indicates that hypnosis (especially when used in combination with cognitive behavioral therapy, exercise, and a low-fat diet) may help overweight or obese people lose weight.

Pregnancy

Pregnant women should not take any herbal remedies or over-the-counter or prescription medications for weight loss.

Obese women who become pregnant are at an increased risk for the following:

• Gestational diabetes -- a diabetic condition that appears during pregnancy and usually goes away after the birth of the baby
• High blood pressure
• Preeclampsia -- a potentially fatal condition causing high blood pressure, fluid retention, and protein in the urine; may cause abdominal pain and vomiting
• Caesarean sections
• Fetal distress -- a condition in which the baby does not receive enough oxygen

Prognosis and Complications

People who are overweight or obese increase their risk for developing the following conditions:

• Type 2 diabetes
• High blood pressure
• Coronary artery disease
• High cholesterol
• High levels of triglycerides (fat) in the blood
• Heart failure
• Respiratory problems (such as sleep apnea)
• Circulatory problems (such as varicose veins)
• Gallbladder disease
• Breast cancer (after menopause) and endometrial cancer
• Prostate cancer
• Colorectal cancer
• Osteoarthritis

Eating and exercise habits are hard to change. Many people are able to lose at least 20 pounds with diet and exercise plans, but only about 10 - 20% can maintain that weight loss for a long period of time. Losing just 15 - 20 pounds, however, can reduce the risk of serious complications, such as diabetes and heart failure, by 10 - 25%.

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