Weight and Obesity
Health guide / Weight and Obesity / Weight loss / Dietary Supplements

Dietary Supplements

Weight-loss supplements

When you're trying to lose weight, you may be tempted to try one of the many weight-loss products advertised on TV or in magazines. But before you do, find out all you can about the product and check with your doctor. Some products can help your efforts to lose weight, provided you understand how they work and how to use them wisely.

But over-the-counter appetite suppressants and dietary supplements can be dangerous if you take too much, take them for too long, or combine them with prescription or nonprescription drugs.

Dietary supplements defined

Dietary supplements are products that contain one or more essential nutrients, such as vitamins, minerals, proteins, and amino acids. The U.S. Food and Drug Administration (FDA) includes herbs in this category, although they are not quite the same as traditional dietary supplements. Dietary supplements come in a variety of forms including tablets, capsules, powders, softgels, gelcaps, liquids, snack bars, and even chewing gum.

Research into dietary supplements and weight loss has uncovered a mixed bag of results. Some supplements, such as pyruvate, seem to have an effect on weight loss, but others, such as chitosan, don't seem to affect weight at all.

Unlike traditional drugs, dietary supplements do not have to be tested for safety and effectiveness before they hit store shelves. The FDA requires labels on supplements that spell out what the product is, what it claims to do, how to use it, and the name and location of the people who make, pack, or ship the product. But the FDA does not enforce accuracy on these labels. You'll also want to look for the U.S. Pharmacopeia (USP) notation on the label — this ensures that the manufacturer follows certain production standards.

Do your own research before you invest in a dietary supplement. One of the best places to start is at the FDA's website. On their MedWatch page, the FDA reports problems linked to dietary supplements; you can also report any adverse effects you've encountered. You might also want to visit ConsumerLab.com, an independent organization that tests and reports on dietary supplements and their manufacturers. And look for the CL seal on dietary supplement products.

With so many products on the market, a complete list isn't possible here, but the following highlights some of the most common ingredients in weight-loss supplements.

Chitosan

What it is

Chitosan is made from the shells of crustaceans.

What it does

Chitosan's supporters believe that it may help your body absorb less fat.

Bottom line

Chitosan's effect on weight loss, if any, is still unknown. Tests on animals revealed that high doses of chitosan given with vitamin C helps lower fat absorption. But in a small British study on 34 overweight men and women, chitosan had no effect on body weight; however, it didn't cause any harmful side effects. If you have an allergy to shellfish, you may also have a life-threatening allergic reaction to chitosan. Chitosan may also interfere with the absorption of some vitamins and prescription drugs.

Chromium picolinate

What it is

Chromium is a trace mineral found in brewer's yeast, unrefined grains and cereals, broccoli, turkey, ham, and grape juice. Chromium picolinate is a man-made form of chromium.

What it does

Chromium helps your body regulate blood sugar, and may help increase HDL ("good" cholesterol) while lowering overall cholesterol levels. Chromium picolinate may also help reduce body fat and increase muscle.

Bottom line

One study of 79 men and 16 women at the Naval Health Research Center in San Diego found that taking high doses (400 mcg) of chromium picolinate for 16 weeks had no effect on weight loss. [2] A German study followed 36 obese men and women for 26 weeks. The participants were put on a low-calorie diet and given either 200 mcg of chromium picolinate, 200 mcg of chromium yeast, or a placebo. Those who took chromium picolinate lost the same amount of weight as the other groups, but increased their muscle mass. So chromium picolinate may help you build muscle, but may not help you lose weight. The daily value for chromium is 120 mcg per day.

Conjugated linoleic acid (CLA)

What it is

CLA is a form of the linoleic acid (one of the fatty acids) present in animal foods, including dairy and meat products.

What it does

Some people theorize that CLA reduces body fat.

Hydroxycitric acid (garcinia cambogia)

What it is

Hydroxycitric acid, very similar to citric acid, is present in plants such as the garcinia cambogia. In fact, you may find hydroxycitric acid marketed as garcinia cambogia, because the plant is such an abundant source of the acid.

What it does

Hydroxycitric acid blocks fatty acid synthesis and increases metabolism. In animal studies, it appears to decrease hunger.

Bottom line

Taking hydroxycitric acid won't hurt you, but it may not help you either. In one study, 135 overweight men and women were put on a low-calorie diet and were given either hydroxycitric acid or a placebo. After 12 weeks, the people who took the placebo actually lost slightly more weight than those taking the supplement.

5-Hydroxytryptophan (5-HTP)

What it is

5-HTP is produced in the body from the amino acid L-tryptophan, which is found in milk and turkey. It, in turn, helps the body make serotonin, which the brain uses to help you fall asleep, keep you emotionally balanced, help you deal with pain, and prevent migraine. The 5-HTP supplement is made from a West African plant.

What it does

Because 5-HTP works on serotonin levels, it elevates mood and works to decrease your appetite.

Bottom line

Research seems to show that 5-HTP does reduce cravings and helps people feel full on less food. In a study at the University of Rome, 20 obese men and women were given either 5-HTP (900 mg a day) or a placebo for 12 weeks. For six weeks the patients ate what they wanted; for the next six weeks they were put on a low-calorie diet. The group that took 5-HTP lost more weight, ate fewer carbohydrates, and tended to be satisfied with less food.

Taking 600 to 900 mg of 5-HTP per day appears to have an effect on weight loss, but that amount can also cause some side effects such as drowsiness, anxiety, headache, or stomach upset. You shouldn't take 5-HTP with antidepressants, weight-control drugs, or other drugs that affect serotonin levels. It should also not be used by people taking drugs that affect liver function, or who already have poor liver function. This supplement has been linked with a potentially fatal blood disorder called eosinophilia myalgia syndrome.

Pyruvate

What it is

Pyruvate is a form of pyruvic acid. Your body makes pyruvic acid when you metabolize carbohydrates and proteins.

What it does

Some people suggest that taking pyruvate supplements may boost metabolism, increase weight and fat loss, and improve exercise tolerance.

Bottom line

A study at Montefiore University Hospital in Pittsburgh tested the effects of pyruvate on cholesterol levels in patients with high cholesterol. Thirty-four patients were put on a low-cholesterol, low-fat diet for four weeks. The patients were then given either pyruvate (22 to 44 grams) or a placebo for six weeks. While pyruvate had little effect on cholesterol levels, the patients who took it lost slightly more weight than the group that took a placebo. A typical dose of pyruvate for weight loss is 30 grams daily. Higher doses can cause gastrointestinal upset.

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