American consumers have long been skeptical about weight-loss supplements, and rightly so. With dozens of nutrients, herbs, and food extracts being marketed as aids for weight loss, there is shockingly little reliable information available concerning the safety and efficacy of any given product. What is more, many so-called miracle pills and quick fixes fail to deliver on the grand weight-loss promises they make, others come with unpleasant side effects, and some have even proven to be dangerous when used incorrectly.

According to Georgetown medical professor Harry Preuss, MD, MACN, CNS, however, there are a number of non-drug weight-loss aids available that do work and can help people shed pounds, build muscle, and burn fat. Based on his own research as well as hundreds of previously recorded scientific studies conducted at major universities and published in leading medical journals, in Dr. Preuss's new book new book with Bill Gottlieb, THE NATURAL FAT-LOSS PHARMACY (Broadway Books, January 2007), he helps consumers separate the good from the bad and the helpful from the hype and lists the safe, effective, and natural weight-loss supplements on the market.

• HCA (hydroxycitric acid): An extract from the rind of the tamarind fruit, HCA interferes with an enzyme that triggers the formation of fatty acids, cholesterol and triglycerides. It helps lower blood levels of leptin (the substance that triggers hunger), increases serotonin and fat oxidation, and increases production of glycogen, leading to a filling of "fullness." Study participants taking HCA ate up to 30% less food at every meal.

• MCT (medium chain triglycerides): This class of fatty saturated acids found naturally in coconut and butter help the body burn more calories up to 25-30% more. The supplement leads to a drop in LDL (bad) cholesterol and reduction in body fat.

• Green and oolong tea extract: One of the antioxidants in gree
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