Q: I'm always hearing mixed information about diet pills? Are they safe to take or not? And do they really work? 

A: Despite many claims for quick weight loss, the safest and best way to lose weight with the least amount of negative side effects remains the tried and true method of eating less calories than you burn on a daily basis through a combination of healthy eating and exercise. However, for various reasons, many people turn to alternative methods including diet pills. 

There are prescription diet pills, the over-the-counter medication, Alli, and many supplements that advertise they will help you lose weight.  Safety is controversial, though, and you should always speak with your doctor prior to taking any diet pills. If you want to lose weight, I recommend that you work with a Registered Dietitian.  And it’s important to note that with any type of weight loss medication, you still need to cut calories and exercise.  And the most effective weight loss is still about ½ - 2 pounds per week. 

Xenical (orlistat) is a prescription drug that blocks fat absorption in the intestines.  This is the same drug as Alli, however Alli is half the strength as the prescription form.  These are considered fat blockers, and it’s necessary to eat a very low-fat diet when taking these. Keep in mind that low-fat diets, without the pill, help promote weight loss. However, with the pill, you will feel sick if you eat more fat than recommended. Possible side effects include oily discharge, fatty stools, gas, and a decreased ability to control bowel movements.  Because less fat is absorbed, less nutrients are absorbed too and so a daily multiple vitamin and mineral supplement is important while on Xenical or Alli. 

Other prescription medications, Meridia (sibutramine) and Phentermine, help you’re your appetite. Possible side effects of Meridia include dry mouth, constipation and insomnia, while possible side effects of Phentermine include depression, insomnia, increased blood pressure, nervousness and irritability. 

Over-the-counter dietary supplements aren’t regulated as either foods or drugs, so as a buyer, you must be beware.  One dangerous supplement, ephedra (ma-haung) has been banned by the Food & Drug Administration (FDA) because of dangerous side effects, including death; however, I’ve still seen this supplement being sold. Supplements have not been proven to promote weight loss and many supplements can negatively interact with prescription medications.  These include St. John’s wort, aloe, cascara, guarana, and herbal diuretics.