Weight-loss "pills" often are viewed with skepticism and for good reason. Many are ineffective...some even are dangerous. But a few nutritional and herbal supplements do work. Some offer bonus health benefits, too. These natural substances have been scientifically shown to aid weight loss by helping the body burn more calories and fat... reducing appetite...improving how the body handles blood sugar...and blocking absorption of fat and carbohydrates.

Laboratory, toxicological and clinical studies—and years of everyday use by millions of people—demonstrate that these supplements are safe. However, it is prudent to take any supplement under the guidance of a qualified health professional. All of the following are available in health-food stores unless otherwise noted.

Green Tea Extract

Green tea contains catechins, a class of powerful antioxidants. EGCG is short for epigallocatechin gallate, the most abundant catechin in green tea.

The Research

In a study published in British Journal of Nutrition, Canadian researchers gave one group of men a supplement containing EGCG and caffeine and another group a placebo. Those who took the supplement burned 180 more calories a day-a level that could help a person shed 22 pounds in a year. For those already at their normal weight, studies show an EGCG/caffeine supplement can help maintain weight. (Previous studies had shown that an EGCG/caffeine combination burns more calories than either EGCG or caffeine alone.)

The combination works by stimulating the sympathetic nervous system, which helps regulate appetite, temperature and many other metabolic processes, including calorie-burning and fat-burning. However, unlike potentially heart-damaging weight-loss herbs, such as ephedra, which also stimulate the sympathetic nervous system, a therapeutic dose of EGCG/caffeine doesn't increase heart rate or significantly boost blood pressure.

Dose: 575 milligrams (mg) of green tea catechins (with 325 mg from EGCG) and 100 mg of caffeine a day. Supplements with this mixture include Schiff-Natural Green Tea Diet and Universal Nutrition-Thermo Green Tea Caps.

Bonus: EGCG may be neuroprotective in humans—it has reduced the severity of Alzheimer's disease in laboratory animals genetically programmed to develop the disease.


Conjugated linoleic acid (CLA) is a type of fatty acid-a building block of fat. It is found in small quantities in meat and milk. CLA can help the body lose fat and build muscle.

The Research

In a study conducted in Norway and published in The American Journal of Clinical Nutrition, 149 women and 31 men received either CLA or a placebo daily. Within three months, the CLA group lost an average of five pounds of body fat and gained two pounds of firming muscle-without dieting or exercise. The placebo group had no change in body composition.

In a study published in the International Journal of Obesity, people who took CLA for six months-from August 2004 through February 2005-experienced no weight gain during the November December holiday period. People who didn't take CLA gained an average of 15 pounds during the holidays.

Researchers don't yet know exactly how CLA works, but it may stop dietary fat from entering fat cells.

Dose: 3.4 grams a day,

Bonus: In a study conducted at the University of British Columbia, people with mild-to-moderate asthma experienced a complete normalization of their airways when they took CLA, which decreases inflammation.


Medium-chain triglycerides (MCTS) are a type of fat. Triglyceride molecules are typically arranged in chains, with carbon atoms as the links. Most triglycerides you eat are long-chain triglycerides, with up to 24 carbon links. MCTs have only six to 12 carbon links. During digestion, long-chain triglycerides combine with transport molecules and travel in the circulatory system, where they're deposited in fat cells. Because of their unique length, MCTs don't require transport molecules - they move directly from the stomach to the liver, where most are instantly incinerated for fuel (and very few are stored as fat). This unusual digestive process increases calorie burning.

The Research

In a study conducted at the University of Manitoba in Canada and published in The American Journal of Clinical Nutrition, 24 men who took MCT supplements burned an average of 100 more calories per day, compared with men who took a placebo.

Dose: MCT is derived from coconut oil, a saturated fat. There have been concerns that MCT supplements could increase cholesterol levels. The MCT formulation used in the study above includes cholesterol-lowering plant sterols—and lowered total cholesterol by 13% and LDL (bad) cholesterol by 14%. This supplement, Slim Smart (www.nfb.ca), is available for sale only through health professionals.


The trace mineral chromium increases the number of insulin receptors on muscle and fat cells, helping those cells utilize blood sugar more effectively. The body uses blood sugar to build muscle, storing less of it as fat.

The Research

In a study of overweight women, those who took chromium supplements while on a diet and exercise program lost weight the healthy way-84% as fat, 16% as muscle. Those who didn't take chromium lost weight but 8% as fat and 92% as muscle.

Losing muscle rather than fat is the sad fate of many dieters. (Evolutionarily, your hunter-gatherer body is programmed to lose muscle, to preserve fat stores in case of famine) Muscle burns many more calories a day than fat, so you end up with a body that burns fewer calories. Post-diet, you return to a normal level of eating but gain weight. Chromium can help prevent this common metabolic problem.

Dose: 600 micrograms (mcg) daily, until you reach your weight-loss goal. The maintenance dose--for lifelong blood sugar balance-is 200 mcg a day.

Caution: Too much chromium can cause major side effects, such as anemia, kidney failure and liver damage. Ask your doctor if chromium is right for you.

Bonus: Because it regulates blood sugar, chromium can help prevent or normalize type 2 diabetes.


An extract of white kidney beans, a starch-blocker limits the action of alpha-amylase, the digestive enzyme that breaks down starch in the intestines. In a study conducted in Italy, 60 overweight but healthy people received either a starch-blocker or a placebo for 30 days while on a diet of 2,000 to 2,200 calories per day that included lots of starch, such as bread and pasta. Those taking the starch-blocker lost an average of seven pounds...those taking the placebo didn't lose weight.

Dose: A dose of 300 mg, taken right before each meal, with eight ounces of water. Look for a product with Phase 2 as the starch-blocker. It's the most widely studied starch-blocker.

How To Choose

With a health professional's guidance, choose one or two supplements that fit your weight-loss goals and lifestyle.

Example: A person eating a lot of carbohydrates might take a starch-blocker to cut absorption and chromium to balance blood sugar.

If after two months or so the selection doesn't seem to be working, stop taking those and try another one or two supplements.

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