Obesity

Related Terms

Adolescent obesity, bariatric surgery, BMI, body mass index, body weight, childhood obesity, diet, endocrine disease, exercise, gastric bypass, liposuction, metabolism, morbid obesity, morbidly obese, obesity in the elderly, overeating, super obesity.

Background

Obesity occurs when an individual has an increased amount of body fat. It is usually defined as being 20-30% above the normal body weight for someone of the same age, gender, and height.
Morbid obesity is usually defined as being 50-100% above the normal body weight for someone of the same age, gender, and height.
Many factors, including an individual's age, gender, and height, are considered to determine if he/she is overweight. People increase in weight until they are fully grown. On average, females tend to gain about 16 pounds of body weight from age 25-54. In contrast, males tend to gain about 10 pounds of body weight from age 25-45. By around age 55, both men and women start to decline in weight. Females naturally have more body fat and less muscles mass than men. It is also normal for taller individuals to weigh more than shorter individuals.
Obesity is typically considered a long-term condition that often persists for many years. Researchers believe that many factors, including poor diet, overeating, pregnancy, medications, medical conditions, genetics, gender, and age, may contribute to a person becoming obese.
Obesity can have serious long-term effects on health. Individuals who are overweight have an increased risk of developing many life-threatening illnesses including heart disease, high blood pressure, stroke, obesity, diabetes, osteoporosis, and cancer. According to the American Heart Association, obesity was associated with nearly 112,000 deaths in 2005.
In the United States, obesity is considered an epidemic. More than half of all Americans are considered overweight, and about 20% of children are overweight. In 2005, 140 million Americans were considered overweight or obese, according to the American Heart Association. Nearly 33% of Americans are considered obese, and these numbers continue to grow.

Signs and symptoms

Patients who are obese have more fat than normal, healthy individuals of the same age, gender, and height. They may have difficulty walking, experience shortness of breath, and become tired after very little physical exertion.

Diagnosis

A healthcare provider diagnoses obesity after measuring the patient's body mass index (BMI) and hip to waist ratio.
The BMI is a measurement of weight (in pounds) for height (in inches) in adults who are older than 20 years of age. BMI falls into one of these categories: below 18.5 units is underweight, 18.5-24.9 is normal, 25.0-29.9 is overweight, and 30.0 and above is obese. For adults, the accepted formula for BMI is: BMI=703 x [Weight in pounds/(Height in inches)2].
Waist to hip ratio (WHR) is the circumference of the waist divided by the circumference of the hips. For women, a healthy ratio is 0.8 or lower. For men, a healthy ratio is 1.0 or lower. A high ratio means that the patient is overweight or obese. A low ratio means that the patient is underweight.

Complications

Depression: Individuals who are obese often suffer from depression. This may occur if the patient's weight limits his/her ability to perform certain activities. Depression may also occur if the patient has poor self-esteem as a result of his/her weight.
Heart disease: Obese individuals have an increased risk of developing high blood pressure. This is because the extra fat tissue, like other tissues in the body, requires oxygen from the blood. Therefore, the circulatory system is strained and the heart rate increases as it tries to supply a larger-than-normal body with enough oxygenated blood.
In addition, obesity tends to increase the amount of insulin in the blood. High levels of insulin cause the body to retain sodium and water, which increases blood volume.
Individuals who are overweight also have an increased risk of developing high cholesterol. High cholesterol can cause plaque deposits to form in the arteries. Plaque is composed of cholesterol, other fatty substances, fibrous tissue, and calcium. When plaque builds up in the arteries, it causes atherosclerosis (hardening of the arteries) or coronary artery disease (CAD). Atherosclerosis can lead to plaque ruptures and blockages in the arteries. If the blood supply to the heart is blocked, a heart attack may occur. If blood supply to the brain is blocked, a stroke may occur.
Sleep apnea: Obese patients have an increased risk of developing sleep apnea, a serious condition that occurs when the individual stops breathing for short periods of time during sleep. In obese patients, sleep apnea typically occurs when excess fat in the upper airway obstructs breathing. Because sleep apnea causes individuals to wake up frequently throughout the night, patients are often drowsy during the day.
Diabetes: Obese patients are more likely to develop type 2 diabetes. This condition occurs when the body becomes resistant to a hormone called insulin. As a result, patients with type 2 diabetes have too much sugar in their bloodstream.
Cancer: Many types of cancer, including colon cancer, rectal colon, esophageal cancer, kidney cancer, breast cancer, and prostate cancer, are associated with being overweight.
Physical discomfort: Obese patients may suffer from chronic pain in various parts of the body. This is because fat eventually starts to crowd the space near the internal organs, impairs blood circulation, and puts extra strain and pressure on the body's joints. Sometimes the fat in the abdomen prevents patients from sitting comfortably. Pain is most likely to develop in the feet, joints, back, and muscles. It may be difficult for obese patients to breathe when they are sitting up.
Fertility problems and sexual dysfunction: Men and women who are obese may suffer from fertility problems. In general, being obese decreases an individual's sex drive (libido). It may also make it be difficult for males to achieve or maintain an erection.
In addition, several studies have found that obesity may decrease an individual's sexual quality of life. Researchers have found that obesity is associated with a lack of enjoyment of sexual activity, lack of sexual desire, difficulties with sexual performance, and avoidance of sexual encounters. Many studies have also found that obese patients who lose weight experience an increase in their sexual quality of life.
Birth defects: Obese females have an increased risk of having children with gestational diabetes or other complications during pregnancy that may lead to birth defects.
Osteoarthritis: Obese individuals are more likely to develop a degenerative joint disease called osteoarthritis. This is because being overweight increases the strain put on the weight-bearing joints, such as the knees and ankles.
Osteoporosis: Obese individuals have an increased risk of developing osteoporosis, which causes the bones to become weak and brittle. The bones become porous and less dense. As a result, individuals are more likely to fracture their bones if they slip, fall, or injure themselves. Some evidence suggests that osteoporosis may develop in obese patients because fat cells infiltrate the bone marrow. In addition, it has been shown that individuals who live sedentary lifestyles have an increased risk of developing osteoporosis.

Treatment

General: Most doctors believe that overweight individuals should try to lose weight gradually. This reduces the risk of nutritional deficiencies and increases the likelihood of long-term success. Individuals who are overweight should aim to lose about one-half to two pounds per week. The safest and most effective way to lose weight is to reduce the amount of calories in the diet and increase physical activity. Individuals should eat sensible portions of foods that are well-balanced.
In serious cases when obesity is causing life-threatening conditions or when all other options have failed, surgical weight-loss procedures (called bariatric surgeries) may be considered. However, individuals must meet specific criteria in order to qualify for weight-loss surgery. In addition, bariatric surgeries, like all surgeries, have potential health risks. Patients should discuss the potential risks and benefits with their healthcare providers before making any decisions about medical treatments.
Exercise programs: Patients who are overweight or obese are encouraged to exercise. Research shows that regular exercise can help individuals live longer, healthier lives. Exercise can help prevent illnesses, such as heart disease, stroke, diabetes, and cancer.
In general, overweight patients should participate in 45-60 minutes of moderate exercise (e.g. brisk walking or jogging) each day in order to prevent becoming obese. Patients who were formerly obese are encouraged to participate in 60-90 minutes of moderate exercise each day along with a healthy, well-balanced diet, in order to prevent gaining the weight back.
Not everyone is able to perform intense types of exercise, such as tennis or running. The American Academy of Family Physicians recommends that individuals who are pregnant or have bone disease or nerve injuries participate in low-impact forms of exercise, such as walking or swimming. Individuals who are overweight or obese may have serious health conditions that limit the type or amount of exercise they can perform. Therefore, patients should talk to their healthcare providers before starting a new exercise plan, especially if they are pregnant, elderly, or have a critical illness or injury. A healthcare provider can work with a patient to design an individualized and safe exercise program.
Healthy diet: In addition to regular exercise, a healthy diet is also important. Individuals should eat well-balanced meals that are sensible portions. The U.S. government issued a revised food pyramid in 2005 to help Americans choose healthier eating habits. The new, updated food pyramid provides 12 different models based on daily calorie needs, ranging from the 1,000-calorie diets for toddlers to 3,200-calorie diets for teenage boys.
Overall, doctors suggest drinking six to eight glasses of water a day and lots of raw fruits and vegetables, especially green leafy vegetables. Some individuals may find it helpful to eat frequent small meals throughout the day to keep the body's energy and metabolism increased. Foods and drinks that contain a lot of sugar and little or no nutritional value should be consumed in moderation. This means individuals should limit their intakes of foods and drinks, such as coffee, alcohol, soft drinks, fruits juices that are high in sugar, processed foods, white sugar, white flour, red meat, and animal fats.
A healthcare provider may recommend a nutritionist to help plan meals that are appropriate for the patient. A nutritionist can help teach the patient what foods are considered healthy and what are not. It is important for the patient to understand the negative impact that poor eating habits have on the body.
Many experts recommend making gradual changes in the diet. This has been shown to help prevent or minimize food cravings. Individuals who slowly change their diets may be more likely to adopt these eating habits as part of their long-term lifestyle.
Appetite suppressants: Appetite suppressants are medications, herbs, or supplements that decrease appetite or make the individual feel full.
Some doctors prescribe appetite suppressant medications to help treat obese individuals. Most individuals who take these medications initially lose between five and 22 pounds. Weight loss is usually greatest during the first few weeks or months of treatment. After about six months, the patient's weight usually levels off. However, most people gain the weight back once they stop taking the medications.
Appetite suppressants can be taken short term (few weeks to a few months) or long term (one year or more), depending on the specific medication prescribed. Diethylpropion (Tenuate?), a short term medication, may increase blood pressure. Phentermine (Fastin?), another short-term medication, has been taken off the market due to increased risk for heart valve disease.
There are also many appetite suppressants that are available over-the-counter. These products can be purchased at health food stores, local pharmacies, or nutrition stores. For instance, an herb called hoodia may cause individuals to feel full. As a result, patients may eat less food. However, no studies have been performed in humans to determine if hoodia is safe and effective in humans.
Dietrine Carb Blocker with Phase 2? is also available over-the-counter. This product is made with an ingredient from white kidney beans that may prevent the body from storing sugar as fat in the body.
While some side effects of U.S. Food and Drug Administration (FDA) approved medications are mild, and may usually go away as treatment is continued, some side effects may be severe and long-lasting. Symptoms may include sleeplessness and/or nervousness. There have also been reports of serious and deadly reactions to appetite suppressants, including primary pulmonary hypertension. Several previously approved drugs, such as phentermine (Fastin?), have caused heart valve disease in patients, and are no longer available.
Other medications: Orlistat (Xenical?) is a lipase inhibitor, which reduces the amount of fat the body can absorb, and is used as long-term medication. About 30% of the fat from foods is excreted instead of being absorbed. Alli? is a reduced-strength form of orlistat (Xenical?) currently available, thus it also functions in weight loss by decreasing fat absorption. Sibutramine (Meridia?), also a long-term medication, aids in weight-loss by blocking the re-uptake of the neurotransmitters serotonin and norepinephrine. These long-term medications may be taken for several months or years. Some individuals may need to take them their entire lives.
Gastric bypass surgery: Gastric bypass surgery, which uses bands or staples to create food intake restriction, is the most common weight loss surgery. The bands or staples are surgically placed near the top of the stomach to section off a small portion that is often called a stomach pouch. A small outlet, about the size of a pencil eraser, is left at the bottom of the stomach pouch. Since the outlet is small, food stays in the pouch longer and the patient also feels full for a longer time. Next, a section of the small intestine is attached to the pouch. This allows food to bypass part of the intestine, resulting in fewer calories being absorbed.
This surgery is often performed in those who have a BMI ?40 (extremely obese) or in patients that have BMIs that are 35-39.9 along with weight-related health problems such as diabetes or high blood pressure.
Surgical candidates go through an extensive screening process. Not everyone who meets the criteria for the surgery is psychologically or medically ready for the surgical procedure. A team of professionals, including a physician, dietitian, psychologist, and surgeon, evaluate whether the surgery is appropriate. Following surgery, physical, nutritional and metabolic counseling are given to prevent nutritional deficiencies. Lifelong use of nutritional supplements such as multivitamins, vitamin B12, vitamin D, and calcium is recommended.
Over two years, gastric bypass surgery patients have been shown to lose two-thirds of excess weight. The improvements observed in type 2 diabetes, high blood pressure, and high blood cholesterol may significantly decrease the risk of heart disease in individuals who have undergone gastric bypass surgery compared to those treated through other means. Gastric bypass surgery has also shown to improve mobility and quality of life for people who are severely overweight.
However, individuals who continue to overeat after undergoing the surgery may stretch out the pouch. As a result, the stomach may become as large as it was prior to surgery, and the patient may gain back weight.
There is a risk of death during gastric bypass surgery. The risk varies depending on age, general health, and other medical conditions.
If the contents of the stomach leaks out of one of the staple lines, the patient will receive antibiotics to prevent an infection. Most cases heal with time. Sometimes, the leak can be serious enough to require emergency surgery.
Excess weight places extra stress on the chest cavity and lungs. As a result, there is a higher risk of developing pneumonia during post-operative recovery when the patient is lying down.
Narrowing of the opening between the stomach and small intestine has occurred. This rare complication may require either an outpatient procedure to pass a tube through the mouth to widen the narrowed opening or corrective surgery.
Gastric bypass can also cause dumping syndrome, a condition where stomach contents move too quickly through the small intestine causing nausea, vomiting, diarrhea, dizziness, and sweating.
Other common complications include dehydration, gallstones, bleeding stomach ulcers, hernia at the incision site, and intolerance to certain foods.
Liposuction: Liposuction is the most frequent cosmetic operation in the United States in which fat tissue is removed. Relatively small amounts of total body fat can be removed safely. However, little weight is lost. Unless the patient makes lifestyle changes, that include regular exercise and a healthy diet, the weight will return. Therefore, liposuction is categorized as a cosmetic surgery rather than a weight loss surgery.
Adjustable gastric banding: A surgical procedure called gastric banding may also be performed. This surgery is designed to make the patient feel full quicker so he/she will eat less and lose weight. During the procedure, the surgeon uses an inflatable band to partition the stomach into two parts. The surgeon then wraps the band around the upper part of the stomach and pulls it tight, like a belt, creating a tiny channel between the two pouches. The band keeps the opening from expanding and is designed to stay in place indefinitely. However, it can be adjusted or surgically removed if necessary. Most surgeons perform this operation using a laparoscope.
Biliopancreatic diversion: During a surgical procedure, called biliopancreatic diversion, a portion of the stomach is removed. The remaining pouch is connected directly to the small intestine, but completely bypasses the small intestine, where most nutrient absorption takes place. This weight-loss surgery offers sustained weight loss, but it presents a greater risk of malnutrition and vitamin deficiencies that requires close monitoring.
Some patients may require vitamin and/or nutritional supplements after the surgery. Other possible complications include infection, blood clot in the lung (called pulmonary embolism), as well as stomach contents leaking into the abdominal cavity.
Vertical banded gastroplasty: This operation divides the stomach into two parts, limiting space for food and forcing the patient to eat less. There is no bypass. Using a surgical stapler, the surgeon divides the stomach into upper and lower sections. The upper pouch is small and empties into the lower pouch, the rest of the stomach. Surgeons use this procedure less frequently than gastric bypass partly because it does not lead to adequate long-term weight loss.
Jaw wiring: Jaw wiring is another option, although it is used infrequently. This is a form of food intake restriction for temporary use in patients who do not have breathing problems. During the procedure, the patient's jaw is wired shut. While the jaw is wired, the patient is only able to consume liquid nutrition through a straw. The wires are typically removed every four to six weeks to allow the patient to exercise the jaw. Treatment may last anywhere from three to six months. Individuals regularly rinse their mouths with mouthwash and use antiseptic wipes on the front of their teeth. When the wires are removed, the patient can brush his/her teeth.
It is recommended that individuals carry wire cutters with them at all times in case of an emergency such as the need to vomit. In general, breathing is not inhibited while the jaw is wired. However, activities that cause deep breathing, such as aerobic exercise, should be avoided.
Although jaw wiring can be effective for short-term weight loss, weight regain occurs soon after the wires are removed. Therefore, it is not considered a conventional weight-loss procedure.
Antidepressants: Depression is commonly associated with obesity. Antidepressants may be prescribed to treat depression in some patients. Drugs called selective serotonin reuptake inhibitors (SSRIs) are the most common type of antidepressants used. Commonly prescribed SSRIs include fluoxetine (Prozac?), fluvoxamine (Luvox?), sertraline (Zoloft?), and paroxetine (Paxil?). Less commonly prescribed antidepressants include clomipramine (Anafranil?), mirtazapine (Remeron?), amitriptyline (Elavil?), and bupropion (Wellbutrin?). Side effects may include nausea, nervousness, insomnia, diarrhea, rash, agitation, or problems with sexual arousal or orgasm.

Integrative therapies

Note: Although some integrative therapies have been shown to promote weight loss, not all treatments are safe. Most experts believe that overweight or obese individuals should aim to lose weight gradually with long-term lifestyle changes that include a healthy diet and regular exercise.
Strong scientific evidence:
Ephedra: Ephedra contains the chemical ephedrine, which appears to cause weight loss when used in combination with caffeine, based on the available scientific evidence. The results of research on ephedrine alone (without caffeine) are unclear. The amounts of ephedrine in commercially available products have widely varied.
However, even though this herb has been shown to help reduce weight, it is unsafe for humans for this indication. Serious reactions, including heart attack, stroke, seizure, and death, have occurred with using ephedra. The U.S. Food and Drug Administration (FDA) has banned sales of ephedra dietary supplements in all states.
Good scientific evidence:
5-HTP: 5-HTP is the precursor for serotonin. Serotonin is the brain chemical associated with sleep, mood, movement, feeding, and nervousness. 5-HTP may alter serotonin levels in the brain, which may then reduce eating behaviors and promote weight loss in obese individuals.
Avoid if allergic to 5-HTP. Use cautiously with a history of psychological disorders. Avoid if pregnant or breastfeeding.
The Atkins Diet: The Atkins Diet? is an eating style that radically departs from the U.S. Food and Drug Administration's (FDA) food pyramid. The Atkins Diet? advocates an increased consumption of fats as the primary source of energy while simultaneously restricting the intake of carbohydrates. This limitation is based on the premise that eating carbohydrates (e.g. bread, cereal, potatoes, or pasta) results in the excessive secretion of insulin, potentially resulting in increased fat stores. A carbohydrate-restricted diet has been shown to result in weight loss in obese and non-obese individuals. Effects at one year may be less and dropout rates are high. Overall the studies suggest that the Atkins Diet? does result in long-term weight loss. However, patients should consult with a qualified healthcare professional before beginning any new diet to discuss possible adverse effects and negative health consequences.
Avoid with severe kidney disease or kidney disorders. Avoid if taking growth hormone. Use cautiously with mood disorders (e.g. depression), schizophrenia, or bipolar disorders, or if taking medications to treat these disorders. Use cautiously in athletes due to potential for muscle cramps, negative feelings towards exercise, fatigue, or hypoglycemia. Use cautiously with osteoporosis, gout, diabetes, menstrual disorders, gastrointestinal disorders, celiac disease, skin conditions, epilepsy, heart disease, anemia, thyroid disorders, or history of stroke or heart attack. Use cautiously in malnourished individuals, vegetarians, or in individuals with absorption concerns. Use cautiously if taking diuretics, medications that alter cholesterol, medications that alter blood sugar, medications for seizures, steroids, or nonsteroidal anti-inflammatory drugs (NSAIDs). Avoid if pregnant or breastfeeding.
DHEA: DHEA (dehydroepiandrosterone) is a hormone that is produced by the adrenal glands. Most human studies investigating the effects of DHEA on weight or fat loss support its use for this purpose.
Avoid if allergic to DHEA. Avoid with a history of seizures. Use cautiously with adrenal or thyroid disorders. Use cautiously if taking anticoagulants, or drugs, herbs, or supplements that treat diabetes, heart disease, seizure, or stroke. Stop use two weeks before and immediately after surgery/dental/diagnostic procedures with bleeding risks. Avoid if pregnant or breastfeeding.
Psychotherapy: Psychotherapy is an interactive process between a person and a qualified mental health professional. The patient explores thoughts, feelings, and behaviors to help with problem solving. Several studies indicate that people who are overweight or obese may benefit from behavioral and cognitive-behavioral psychotherapy in combination with diet and exercise to lose weight.
Psychotherapy cannot always fix mental or emotional conditions. Psychiatric drugs are sometimes needed. In some cases, symptoms may worsen if the proper medication is not taken. Not all therapists are qualified to work with all problems. Use cautiously with serious mental illnesses or some medical conditions because some forms of psychotherapy may stir up strong emotional feelings and expression.
Unclear or conflicting scientific evidence:
Acupuncture: Acupuncture is commonly used throughout the world. According to Chinese medicine theory, the human body contains a network of energy pathways through which vital energy, called "chi," circulates. These pathways contain specific "points" that function like gates, allowing chi to flow through the body. Needles are inserted into these points to regulate the flow of chi. Studies have produced inconclusive evidence on whether acupuncture might contribute to weight loss. Some studies show modest benefit but others show none. Currently, there is insufficient available evidence to recommend either for or against acupuncture in weight loss.
Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, medical conditions of unknown origin, or neurological disorders. Avoid on areas that have received radiation therapy and during pregnancy. Avoid if taking anticoagulants. Use cautiously with pulmonary disease (e.g. asthma or emphysema). Use cautiously in elderly or medically compromised patients, diabetics, or with a history of seizures. Avoid electroacupuncture with arrhythmia (irregular heartbeat) or in patients with pacemakers.
Ayurveda: Ayurveda is a form of natural medicine that originated in ancient India more than 5,000 years ago. Evidence is inconclusive on whether the traditional herb guggulu (Medohar) may contribute to weight loss in obese patients. More studies are needed to examine this treatment.
Ayurvedic herbs should be used cautiously because they are potent, and some constituents can be potentially toxic if taken in large amounts or for a long time. Some herbs imported from India have been reported to contain high levels of toxic metals. Ayurvedic herbs can interact with other herbs, foods, and drugs. A qualified healthcare professional should be consulted before taking. Use guggul cautiously with peptic ulcer disease. Avoid sour food, alcohol, and heavy exercise with guggul. Mahayograj guggul should not be taken for long periods of time. Avoid Ayurveda with traumatic injuries, acute pain, advanced disease stages, or medical conditions that require surgery.
Betaine anhydrous: Betaine is found in most microorganisms, plants, and marine animals. There is currently insufficient available evidence supporting betaine for weight loss.
Avoid if allergic to betaine anhydrous or cocamidopropylbetaine, a form of betaine. Use cautiously with kidney disease, obesity, or psychiatric conditions. Avoid if pregnant or breastfeeding.
Bitter orange: Bitter orange (Citrus aurantium) comes from a flowering, fruit-bearing evergreen tree native to tropical Asia. It is now widely grown in the Mediterranean region and elsewhere. Bitter orange is a common ingredient in dietary supplements as a weight loss aid and appetite suppressant. Since the ban on ephedra, some weight loss products previously containing ephedrine have been reformulated to include bitter orange. Although bitter orange is popularly used for weight loss, the effects of bitter orange are largely unknown, and more study is needed to make a strong recommendation.
Avoid if allergic or hypersensitive to bitter orange or any members of the Rutaceae family. Avoid with heart disease, narrow-angel glaucoma, intestinal colic, or long QT interval syndrome. Avoid if taking anti-adrenergic agents, beta-blockers, QT-interval prolonging drugs, monoamine oxidase inhibitors (MAOIs), stimulants, or honey. Use cautiously with headache, overactive thyroid, or if fair-skinned. Avoid if pregnant or breastfeeding.
Calcium: Calcium is the most abundant mineral in the human body. Calcium is needed for muscle contraction, blood vessel contraction and expansion, the release of hormones and enzymes, and nervous system signaling. Diets with higher calcium density (high levels of calcium per total calories) have been associated with a reduced incidence of being overweight or obese in several studies. While more research is needed to understand the relationships between calcium intake and body fat, these findings emphasize the importance of maintaining an adequate calcium intake while attempting to diet or lose weight.
Avoid if allergic or hypersensitive to calcium or lactose. High doses taken by mouth may cause kidney stones. Avoid with high levels of calcium in the blood, high levels of calcium in urine, high levels of parathyroid hormone, bone tumors, digitalis toxicity, ventricular fibrillation (ventricles of the heart contract in unsynchronized rhythm), kidney stones, kidney disease, or sarcoidosis. Use cautiously with achlorhydria (absence of hydrochloric acid in gastric juices) or arrhythmia (irregular heartbeat). Calcium appears to be safe in pregnant or breastfeeding women. Talk to a healthcare provider to determine appropriate dosing during pregnancy and breastfeeding. Calcium supplements made from dolomite, oyster shells, or bone meal may contain unacceptable levels of lead.
Damiana: Damiana, which includes the aromatic species Turnera diffusa and Turnera aphrodisiaca,grows wild in the subtropical regions of the Americas and Africa. "YGD," containing yerbe mate (leaves of Ilex paraguayenis), guarana (seeds of Paullinia cupana), and damiana (leaves of Turnera diffusa var. aphrodisiaca), is an herbal preparation frequently used for weight loss. More studies using damiana alone are needed before a recommendation can be made.
Avoid if allergic/hypersensitive to Turnera diffusa, Turnera aphrodisiaca, their constituents, or related plants in the Turneraceae family. Use cautiously with a history of breast cancer. Avoid with Alzheimer's disease or Parkinson's disease. Use cautiously with psychiatric disorders. Use cautiously if taking medications that alter blood sugar levels.
Evening primrose: Evening primrose oil contains an omega-6 essential fatty acid called gamma-linolenic acid (GLA), believed to be the active ingredient. Initial human study suggests that evening primrose oil may have no effects on weight loss.
Avoid if allergic to plants in the Onagraceae family (e.g. willow's herb or enchanter's nightshade), or gamma-linolenic acid. Avoid with seizure disorders. Use cautiously if taking mental illness drugs. Stop use two weeks before surgery with anesthesia. Avoid if pregnant or breastfeeding.
Garcinia: Garcinia cambogia is an extremely small purple fruit that is naturally found in India and Southeast Asia. Evidence supporting hydroxycitric acid, the active ingredient in Garcinia cambogia, for weight loss is mixed. Additional study is warranted to clarify early findings.
Avoid if allergic or hypersensitive to Garcinia cambogia. Use cautiously with a history of diabetes, rhabdomyolysis (breakdown of skeletal muscle), or with HMG-CoA reductase inhibitors ("statins"). Avoid with Alzheimer's disease. Avoid if pregnant or breastfeeding.
Green tea: Green tea is made from the dried leaves of Camellia sinensis, an evergreen shrub. Green tea has a long history of use, dating back about 5,000 years ago in China. There are several small human studies addressing the use of green tea extract (GTE) capsules for weight loss or weight maintenance in overweight or average weight individuals. Study results are mixed. Better research is needed before a recommendation can be made in this area.
Avoid if allergic or hypersensitive to caffeine or tannin. Use cautiously with diabetes or liver disease.
Guarana: Guarana is a native species of South America and has stimulating properties when taken orally. Guarana has the same stimulatory effect as caffeine and is often used for energy, weight loss, and as an additive to soft drinks (e.g. Dark Dog Lemon?, Guts?, and Josta?). Caffeine has been used as a weight loss agent due to its ability to burn calories by increasing heat output. In available studies, guarana has been studied with other herbs, making it difficult to draw a conclusion based on the effects of guarana alone. Additional study is needed in this area.
Avoid if allergic to guarana (Paullinia cupana), caffeine, tannins, or related species of the Sapindaceae family. Avoid with high blood pressure, psychological or psychiatric disorders, liver disorders, or irregular heartbeat. Avoid if taking other stimulatory agents, especially ephedra. Use cautiously with breast disease, impaired kidney function, diabetes, pre-existing mitral valve prolapse, iron deficiency, gastric or duodenal ulcers, bleeding disorders, glaucoma, or if at risk for osteoporosis. Use cautiously if undergoing electroconvulsive therapy (ECT). Avoid if pregnant or breastfeeding.
Guggul: Guggul (gum guggul) is a resin produced by the mukul mirth tree. There is insufficient evidence to support the use of guggul or guggul derivatives for the management of obesity.
Avoid if allergic to guggul. Avoid with a history of thyroid disorders, anorexia, bulimia, or bleeding disorders. Avoid if pregnant or breastfeeding.
Hypnosis, hypnotherapy: Hypnosis is a trance-like state in which a person becomes more aware and is more open to suggestion. Hypnotherapy has been used to treat health conditions or to change behaviors. Research suggests that hypnosis may be valuable as an adjunct to cognitive behavioral therapy for weight loss. However, it is unclear if hypnotherapy used alone is beneficial in this area.
Use cautiously with mental illnesses (e.g. psychosis/schizophrenia, bipolar disorder, multiple personality disorder, or dissociative disorders) or seizure disorders.
L-carnitine: L-carnitine is an amino acid. Early evidence shows that L-carnitine may have no effect on weight loss in obese patients. Further studies are needed before a firm conclusion can be made.
Avoid if allergic or hypersensitivity to carnitine. Use cautiously with peripheral vascular disease, high blood pressure, alcohol-induced liver cirrhosis, or diabetes. Use cautiously in low birth weight infants and individuals on hemodialysis. Use cautiously if taking anticoagulants (blood thinners), beta-blockers, or calcium channel blockers. Avoid if pregnant or breastfeeding.
Licorice: Licorice is harvested from the root and dried rhizomes of the low-growing shrub Glycyrrhiza glabra. Preliminary data show that licorice may reduce body fat mass. Further research is needed to confirm these results.
Avoid if allergic to licorice, any component of licorice, or any member of the Fabaceae (Leguminosae) plant family. Avoid licorice with congestive heart failure, coronary heart disease, kidney disease, liver disease, fluid retention, high blood pressure, hormonal abnormalities, or if taking diuretics. Licorice can cause abnormally low testosterone levels in men or high prolactin or estrogen levels in women. This may make it difficult to become pregnant and may cause menstrual abnormalities.
Lutein: Lutein and zeaxanthin are found in high levels in foods such as green vegetables, egg yolk, kiwi fruit, grapes, orange juice, zucchini, squash, and corn. Currently, there is insufficient available evidence to recommend for or against the use of lutein for obesity.
Avoid if allergic or hypersensitive to lutein or zeaxanthin. Use cautiously if at risk for heart disease or cancer. Avoid if pregnant or breastfeeding.
Macrobiotic diet: Macrobiotics is a popular approach to diet that stresses vegetarianism and consumption of whole, healthy foods. Proponents of macrobiotics advocate a flexible approach that allows supplementation with dairy, fish, or other supplements as needed on an individual basis. There is evidence that a macrobiotic diet may lead to reduced body size and obesity, as well as increased leanness in preschool children compared to children on a normal diet. Studies are needed to determine whether or not these changes contribute to good health in children.
The macrobiotic diet poses a risk of nutrition deficiencies. However, this can be avoided with appropriate menu planning. Use cautiously with cancer or other medical conditions without expert planning or supplementation. Not recommended in children or adolescents without professional guidance or appropriate supplementation. Not recommended in pregnant or lactating women due to potential deficiencies, unless properly supplemented.
Moxibustion: Moxibustion is a therapeutic method in traditional Chinese medicine, classical (five element) acupuncture, and Japanese acupuncture. During moxibustion, an herb (usually mugwort) is burned above the skin or on the acupuncture points for the purpose of introducing heat into an acupuncture point to alleviate symptoms. It may be applied in the form of a cone, stick, or loose herb; or it may be placed on the head of an acupuncture needle to manipulate the temperature gradient of the needle. Evidence does not support use of moxibustion to aid in weight loss at this time, although it may contribute to increased psychological well-being and improved eating attitudes in obese patients. More studies are needed to determine whether or not moxibustion may play a role in weight loss.
Use cautiously over large blood vessels and on thin or weak skin. Avoid with aneurysms, any kind of "heat syndrome," heart disease, convulsions, cramps, diabetic neuropathy, extreme fatigue, anemia, fever, or inflammatory conditions. Avoid over allergic skin conditions, ulcerated sores, skin adhesions, areas of inflammation, or over contraindicated acupuncture points. Avoid use on the face, genitals, head, nipples, or skin adhesions. Avoid in patients who have just finished exercising or taking a hot bath or shower. Use cautiously in elderly people with large vessels. Not advisable to bathe or shower for up to 24 hours after a moxibustion treatment. Avoid if pregnant or breastfeeding.
Psyllium: Psyllium, also known as ispaghula, comes from the husks of the seeds of Plantago ovata. The reviewed evidence seems to show that psyllium may improve blood sugar and lipid levels, which has been associated with obesity in some children. However, further studies are needed to clarify its effects and the mechanisms involved. Body weight reduction has not been proven to be associated with psyllium use in adults.
Avoid if allergic or hypersensitive to psyllium, ispaghula, or English plantain (Plantago lanceolata). Prescription drugs should be taken one hour before or two hours after psyllium. Use cautiously if pregnant or breastfeeding because psyllium may lower blood sugar levels.
Rhubarb: In traditional Chinese medicine (TCM), rhubarb is used as an ulcer remedy, and it is considered a bitter, cold, dry herb used to "clear heat" from the liver, stomach, and blood. One three-stage study looked at the effects of rhubarb on simple obesity. Although the study indicates a positive effect compared to two other obesity treatments and a control group, more high-quality studies are needed to confirm rhubarb's role in weight gain and loss.
Avoid if allergic to rhubarb, its constituents, or related plants from the Polygonaceae family. Avoid using rhubarb for more than two weeks. Avoid with atony, colitis, Crohn's disease, dehydration electrolyte depletion, diarrhea, hemorrhoids, insufficient liver function, intestinal obstruction, ileus, irritable bowel syndrome (IBS), menstruation, pre-eclampsia, kidney disorders, ulcerative colitis, or urinary problems. Avoid handling rhubarb leaves, as it may cause contact dermatitis. Avoid rhubarb in children younger than age 12 due to water depletion. Use cautiously with bleeding disorders, heart conditions, constipation, thin or brittle bones, or with a history of kidney stones. Use cautiously if taking anti-psychotic drugs, anticoagulants, or oral drugs, herbs, or supplements (including calcium, iron, and zinc). Avoid if pregnant or breastfeeding.
Seaweed, kelp, bladderwrack: Bladderwrack (Fucus vesiculosus) is a brown seaweed found along the northern coasts of the Atlantic and Pacific oceans and North and Baltic seas. There is not enough scientific evidence to determine if bladderwrack can help obese patients lose weight. Further research is warranted in this area.
Avoid if allergic or hypersensitive to Fucus vesiculosus or iodine. Avoid with a history of thyroid disease, bleeding, acne, kidney disease, blood clots, nerve disorders, high blood pressure, stroke, or diabetes. Avoid if pregnant or breastfeeding.
Soy: Due to limited human study, there is not enough evidence to recommend for or against the use of soy for weight reduction. Further research is needed before a recommendation can be made.
In theory, soy supplements may interfere with the effects of some chemotherapy regimens or radiation therapy because of its antioxidant properties. Use cautiously if taking anticoagulants. The use of soy is often discouraged in patients with hormone-sensitive cancer (e.g. such as breast, ovarian, or uterine cancer) due to concerns about possible estrogen-like effects, which may theoretically stimulate tumor growth.
Spirulina: The term spirulina refers to a large number of cyanobacteria, or blue-green algae. Spirulina is a popular therapy for weight loss, and it is sometimes marketed as a "vitamin enriched" appetite suppressant. However, little scientific information is available on the effects of spirulina on weight loss in humans.
Avoid if allergic or hypersensitive to spirulina or blue-green algae. Avoid with phenylketonuria. Avoid if pregnant or breastfeeding.
Taurine: Currently, there is insufficient available evidence to recommend for or against the use of taurine in the treatment of obesity.
Taurine is an amino acid and it is unlikely that there are allergies related to this constituent. However, allergies may occur from multi-ingredient products that contain taurine. Use cautiously with high VLDL cholesterol, hypertriglyceridemia, or with a history of low blood pressure, coagulation disorders, potential for mania, or epilepsy. Use cautiously if taking hypolipidemic medications or hypotensive, hypoglycemic, anti-platelet, or anticoagulant medications. Avoid consumption of energy drinks containing taurine, caffeine, glucuronolactone, B vitamins, and other ingredients before consuming alcohol or exercising. Use cautiously if pregnant or breastfeeding. Taurine is a natural component of breast milk.
Vitamin A (retinol): Vitamin A is a fat-soluble vitamin that is derived from two sources: retinoids and carotenoids. Retinoids are found in animal sources (e.g. livers, kidneys, eggs, and dairy products). Carotenoids are found in plants (e.g. dark or yellow vegetables). Daily vitamin A with calcium has been suggested for weight loss. In one study, an average loss of two pounds was reported after two years of supplementation in young women. However, further research is needed before a firm conclusion can be made in this area.
Avoid if allergic or hypersensitive to vitamin A. Vitamin A toxicity can occur if taken at high dosages. Use cautiously with liver disease or alcoholism. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or heart disease. Vitamin A appears safe in pregnant women if taken at recommended doses. Use cautiously if breastfeeding because the benefits or dangers to nursing infants are not clearly established.
Yoga: Yoga is an ancient system of relaxation, exercise, and healing with origins in Indian philosophy. Yoga has been described as "the union of mind, body, and spirit," which addresses physical, mental, intellectual, emotional, and spiritual dimensions towards an overall harmonious state of being. Preliminary research does not provide clear answers. Yoga, in addition to healthy eating habits, may reduce weight. Better studies are necessary to form conclusions about the potential benefits of yoga alone.
Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, cervical spondylitis, or if at risk for blood clots. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction. However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.
Traditional or theoretical uses lacking sufficient evidence:
Gymnema: While preliminary research reports that gymnema may be beneficial in patients with type 1 or type 2 diabetes, there is currently no available clinical evidence with use of gymnema for obesity, a purported traditional or theoretical use. High quality human research is needed in this area to further understand gymnema's potential use for obesity.
Hoodia: Hoodia (Hoodia gordonii) has purportedly been used and recently marketed as an appetite suppressant and weight reduction aid. Secondary sources note that the Bushmen of the Kalahari have eaten it to help ward off hunger and thirst during long trips in the desert.
Unlike ephedra, hoodia does not appear to work as a stimulant, but rather it acts as an appetite suppressant. The pharmaceutical company, Phytopharm, has found hoodia promising and is currently attempting to isolate the appetite-suppressing molecule, P57, to create a patented diet drug in the future. P57 was at one time licensed to Pfizer for development, but was discontinued in 2003.
There are currently no available reliable human trials demonstrating efficacy and safety of hoodia for any indication. Additional research is needed in this area before a clinical recommendation can be made.
Fair negative scientific evidence:
Acupressure, shiatsu: During acupressure, finger pressure is applied to specific acupoints on the body. Preliminary evidence suggests that acupressure may not be effective for weight loss.
With proper training, acupressure appears to be safe if self-administered or administered by an experienced therapist. No serious long-term complications have been reported, according to scientific data. Hand nerve injury and herpes zoster ("shingles") cases have been reported after shiatsu massage. Forceful acupressure may cause bruising.
Beta-glucan: Beta-glucan is a fiber derived that comes from the cell walls of algae, bacteria, fungi, yeast, and plants. Researchers suggest different types of fiber may have an effect on satiety and energy intake. Short-term use of fermentable fiber or nonfermentable fiber supplements does not appear to promote weight loss. More study is needed to confirm these findings.
Avoid if allergic or hypersensitive to beta-glucan. When taken by mouth, beta-glucans are generally considered safe. Use cautiously with AIDS or AIDS-related complex (ARC). Avoid using particulate insoluble beta-glucan, as preliminary evidence suggests intravenous beta-glucans in the microparticulate form may cause serious side effects including hepatosplenomegaly (enlargement of both the liver and the spleen). Avoid if pregnant or breastfeeding.

Prevention

Awareness: Individuals should regularly visit their healthcare providers and know what their healthy weight should be. Individuals should also regularly weigh themselves so they can make lifestyle changes if they start to gain weight.
Individuals who are overweight or obese should be aware of the health risks associated with these conditions, including high blood pressure, high cholesterol, diabetes, heart disease, stroke, and diabetes. In order to prevent these complications, overweight individuals should make lifestyle changes to promote weight loss.
Exercise: Regular exercise can help individuals maintain a healthy weight. It has also been shown to control diabetes, reduce stress, and reduce the risk of heart disease and stroke. Thirty minutes daily of exercise is normally recommended. Patients should talk to their healthcare providers before starting new exercise programs.
Diet: Eating a healthy and well-balanced diet is essential to maintaining a healthy weight. A healthy diet should include five or more daily servings of fruits and vegetables, foods rich in soluble fiber (such as oatmeal and beans), foods rich in calcium (such as dairy products, spinach), soy products (such as tempeh, miso, tofu, and soy milk), and foods rich in omega-3 fatty acids, including cold-water fish (such as salmon, mackerel, and tuna).
Stress management: Because stress may increase the risk of becoming obese, stress management is recommended.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

American Society for Metabolic and Bariatric Surgery.
Assimakopoulos K, Panayiotopoulos S, Iconomou G, et al. Assessing sexual function in obese women preparing for bariatric surgery. Obes Surg. 2006 Aug;16(8):1087-91.
Centers for Disease Control and Prevention (CDC). .
Gordon-Larsen P. Obesity-related knowledge, attitudes, and behaviors in obese and non-obese urban Philadelphia female adolescents. Obes Res. 2001 Feb;9(2):112-8.
Kolotkin RL, Binks M, Crosby RD, et al. Obesity and sexual quality of life. Obesity (Silver Spring). 2006 Mar;14(3):472-9.
Kolotkin RL, Head S, Hamilton M, et al. Assessing Impact of Weight on Quality of Life. Obes Res. 1995 Jan;3(1):49-56.
National Heart, Lung, and Blood Institute. .
Natural Standard: The Authority on Integrative Medicine. .
Nguyen-Michel ST, Unger JB, Spruijt-Metz D. Dietary correlates of emotional eating in adolescence. Appetite. 2007 Mar 19; [Epub ahead of print.]
No authors listed. A critique of low-carbohydrate ketogenic weight reduction regimens. A review of Dr. Atkins' diet revolution. JAMA 6-4-1973;224(10):1415-1419.
Oliver G, Wardle J, Gibson EL. Stress and food choice: a laboratory study. Psychosom Med. 2000 Nov-Dec;62(6):853-65.
U.S. Food and Drug Administration (FDA). .
Viner RM, Haines MM, Taylor SJ, et al. Body mass, weight control behaviours, weight perception and emotional well being in a multiethnic sample of early adolescents. Int J Obes (Lond). 2006 Oct;30(10):1514-21. Epub 2006 May 23.
Wilson LF. Adolescents' attitudes about obesity and what they want in obesity prevention programs. J Sch Nurs. 2007 Aug;23(4):229-38.

Causes

General: There are many potential causes of obesity. Some patients may be obese for multiple reasons.
Poor diet: Individuals who regularly consume foods that are high in calories and saturated fats have an increased risk of becoming obese. Examples of foods and beverages that may lead to obesity include fast food, fried food, sodas, candy, and desserts.
To maintain a healthy weight, an individual's intake of calories should be about equal to the calories used or burned during the day. If an individual eats more calories than are burned, the body stores the extra calories as fat. That is why someone who leads a sedentary, or inactive, lifestyle would most likely gain weight if they ate the same amount of food as someone who goes running every day.
Overeating: Consistently eating too much food also increases the risk of becoming obese. Individuals who regularly eat extra-large portions of food, eat until they are full, or eat many times throughout the day are more likely to become obese.
Inactivity: Individuals who do not exercise regularly are more likely to become obese. Physical activity is needed to burn the calories that are consumed in the diet. If these calories are not burned, they will be stored as fat in the body. Most experts recommend at least 30 minutes of moderate exercise three or more times per week to help maintain a healthy weight.
Pregnancy: During pregnancy, the female's body weight increases, not only because she is carrying a baby, but also because the mother's body needs to support the growing fetus. The average weight gain after pregnancy is typically 25-35 pounds. Researchers believe that this weight gain may contribute to the development of obesity.
Medications: Some medications, including corticosteroids and tricyclic antidepressants, may cause weight gain as a side effect.
Medical conditions: Although it is uncommon, sometimes obesity is caused by medical conditions. For instance, if the thyroid does not produce enough thyroid hormone, the metabolism slows down and it may lead to mild weight gain and difficulty losing extra weight.
In addition, some long-term conditions, such as emphysema or arthritis, may limit an individual's ability to exercise. As a result, individuals may become overweight or obese.
Stress: Stress may also contribute to obesity. When an individual becomes stressed, it signals the adrenal glands to release a hormone called cortisol. Research suggests that increase in cortisol levels may lead to increased fat around the midsection.
In addition, recent research suggests that there is a connection between high levels of stress and the desire to eat. It has been proposed that comfort foods, specifically those that are high in fats and sugars, may help reduce the body's response to stress and limit the amount of cortisol that is released. However, individuals who frequently indulge in these foods typically develop excess abdominal fat, which has been associated with an increased risk of heart disease and stroke.
Genetics: Genetics may also contribute to obesity. For instance, a patient's genetics may affect how much fat is stored and where it is distributed in the body. Genetics may also affect how quickly the body is able to convert food into energy and how efficiently the body is able to burn calories during physical activity. Although genetics can increase an individual's risk of becoming obese, it is not the only factor for the condition. In other words, individuals who are genetically predisposed to become obese will not always become obese, especially if they make the right lifestyle choices.
Gender: Women are more likely to become obese than men. This is because women naturally have more body fat and less muscle mass than men. In addition, women burn fewer calories at rest than men do. As a result, women are more likely experience an increase in body fat than males.
Age: Age may also contribute to obesity. Muscle mass tends to decrease with age, which decreases the body's metabolism, or rate at which the body is able to process fats. In addition, most patients become less active as they age. All of these changes lead to a decrease in the amount of calories that body needs. If individuals do not decrease the amount of calories they consume, they will start to gain weight.