5 facts about diet pills you should know

There are pills for people who weigh too much — quite a few, actually. But they won't make the weight magically disappear. Here's some things you need to know about diet pills.

• There's a variety of ingredients in some of these pills that may curb appetite and burn a few extra calories, but there's no telling what's actually in your pill bottle.
• About 20 percent of American women have tried one at some point, and some of the pills may even help — a little.
• Diet pills won't work without diet and exercise, and data on long-term effects is lacking.

Most weight-loss pills work in one of two ways:

1. They curb your appetite by releasing chemicals such as epinephrine that speed up your metabolism — often causing jitters.
2. They inhibit the breakdown and absorption of the fat in the food you eat. These pills often cause loose, oily stools and other, even more unappealing side effects, such as "anal leakage."

• The drugs are meant to be used along with, not instead of, dietary changes and exercise.
• Diet pills  can work, at least in the short term, but researchers say they don't meet the unrealistic expectations of patients or health care professionals.
• Most of these drugs are meant for short-term use only. Once you build up a tolerance to the drug and stop feeling an effect, you're not supposed to increase the dose
• Many experts argue that the role of these drugs is to give patients an opportunity to learn to eat better and make time for exercise.
• The appetite suppressants modify patients' brain chemistry. This makes it easier stick to a diet, resist compulsions to eat and build confidence.

• Drugs that speed the metabolism also raise the risk of high blood pressure and may cause a rapid heartbeat, dizziness and restlessness.
• Drugs that block the absorption of fat also block the absorption of fat-soluble vitamins such as beta-carotene and vitamins D and E.
• People who take those drugs should also take a multivitamin several hours before or after.
• With either type of drug, unless you've made lasting lifestyle changes, your weight will go right back up once you go off the medication.

• Some manufacturers have turned to ingredients such as bitter orange, green tea and guarana. These are all purported to boost metabolism and suppress the appetite.
• These pills have some effect in the body, but clinical studies have been scant, results have been mixed and no studies have assessed their long-term effects.
• Remember: since there's no regulatory body that governs supplements, there's no telling for sure what's really in the bottle you buy.
• Formulas vary widely in terms of the quantity and quality of their effective ingredients.

Today's diet drugs are safer and more effective than older drugs, but side effects and safety concerns remain. Your best defence against dangerous diet pills is knowledge, so learn what you need and make an informed decision.