Obesity is on the rise due to bad diets and sedentary lifestyles. Body mass index (BMI) is the most commonly used measure for assessing if someone is overweight. This is calculated by dividing weight in kilograms by height in meters squared and is a way of roughly assessing if someone is the right weight for their height.
Those with a BMI over 30 can be offered drug therapy if they fail to lose weight with lifestyle changes
 Why should I be aware of this?
Many experts feel that these drugs could cause severe psychiatric symptoms. Obese patients are in general more prone to depression and they may suffer from lack of self confidence and other body image disorders. When on drugs these problems tend to get accentuated. There may be loss of weight as there is also a close association between depression and eating disorders.
 How does this affect me?
Many anti-obesity drugs are also known to cause various degrees of side effects like depression and anxiety. Some doctors insist that while it is known to cause severe side effects in about 20 per cent of patients, there are others who benefit from it.
 All about anti-obesity drugs
There are many risks associated with anti-obesity drugs even those prescribed by a doctor or suggested by a nutritionist. Like many drugs, there is a high risk of addiction with diet pills. As most diet and weight loss pills are stimulants, there is a high risk of addiction and the body can become dependent on them. This is an unnatural state and an unhealthy way to lose weight.
Some weight loss pills will cause glaucoma, an eye condition which will damage an individual's ability to see clearly. Glaucoma is degenerative. Symptoms of other drugs may include abdominal cramps, diarrhea, urgency to defecate, oily formed stools, and increased number of bowel movements.
Not much information is available on the long-term effectiveness of anti-obesity drugs. Studies have, however shown that majority of people who stop taking the drugs regain weight. When a change in lifestyle can bring about weight loss, in most cases the drugs may not be necessary.
 Prescription and OTC
While there are drugs which have to be prescribed, there are several over-the-counter drugs which may be available right in your local drugstore or supermarket.
Herbal diet supplements are also available without a prescription. You'll typically find a huge variety of these in health food and nutrition stores as well as in regular supermarkets. Herbal supplements are often labeled "all natural" and are considered by the FDA to be food products as opposed to drugs.
 Appetite suppressant
Another form of ant-obesity drug is called appetite suppressant which decreases appetite and gives a sensation of being full.
In 1997 the US Food and Drug Administration (FDA) removed two popular appetite suppressants from the market - fenfluramine and dexfenfluramine. The combination of the drugs with another appetite suppressant drugs, phentermine, caused heart disease and life-threatening pulmonary hypertension - a disease of the blood vessels of the heart and lungs.
 What can I do?
Each person's body already metabolizes food and fat intake very differently. Risks with diet pills are generally associated with our lack of awareness of how and why certain pills seem to work.
- Always consult a doctor before using any type of weight loss drug.
- Going natural - using the power of plants and substances created by nature - is the best way to shed the extra weight in a reasonably paced process.
- Anaerobic exercise, such as strength training, lifting weights, or short bursts of intense energy do not really burn fat. The best exercise for fast weight loss is exercise of the cardio or aerobic variety. This includes any exercise that increases your heart rate for sustained periods of time (30 to 60 minutes) and can be performed anywhere.
- Even doing house chores can be called cardio if it lasts long enough and if it raises the heart rate
- Not all obese patients respond to drug therapy. An anti-obesity drug should therefore be prescribed for no longer than 12 weeks in the first instance and weight loss should then be measured.
- Rapid weight regain is common after short-term use of anti-obesity drugs (12 weeks or less).
- The duration of treatment with an anti-obesity drug must never exceed the time period recommended by the product license for the drug.
- The prescription of an anti-obesity drug should only be made in appropriate clinical settings.
- All obese patients receiving drug therapy should be given regular review. 
Drugs used to treat obesity may be effective against a wide range of viral infections such as the flu, hepatitis, and even HIV, according to researchers from the University of Rochester Medical Center and Princeton University.
In cellular metabolism, glucose can be converted into fatty acids -- a process known as fatty acid biosynthesis. Fatty acid biosynthesis is not essential in humans, but many viruses use these fatty acids to build their viral envelopes, or outer coatings, which help the viruses penetrate and infect human cells. 
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- ANTI OBESITY DRUGS