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Diet or Dietary Supplements

The 1994 Dietary Supplement Health and Education Act (DSHEA) defines a dietary supplement as a product taken orally that adds to a person's diet through the use of nutritional ingredients. Examples of dietary supplements include vitamins, minerals, herbs, and enzymes. Some diet pills used to enhance weight loss are marketed as nonprescription dietary supplements.

Diet or Dietary Supplements - FDA Regulation

Regulation of diet supplements by the Food and Drug Administration (FDA) is much laxer than for prescription weight loss drugs. Prescription diet drugs must be tested for safety and effectiveness before being sold and administered. Drug manufacturers must record, research, and share with the FDA any information about illnesses or injuries pertaining to their products. However, the FDA views diet supplements as foods rather than drugs. Diet supplements do not require FDA approval unless they contain a new ingredient that must be tested. The 1994 DSHEA places the initial responsibility of determining whether or not a product is safe on the maker. The FDA must demonstrate that a dietary supplement has harmed consumers before it can stop it from being sold. Once a brand of diet supplements is on the market, recording and monitoring of ill-effects caused by the diet supplements is the voluntary responsibility of the manufacturer.

Diet or Dietary Supplements

Diet Supplements - Ineffective for Weight Loss

There is no evidence that the use of diet supplements alone, causes weight loss. Some weight loss trials have indicated small additional weight loss benefits for people taking diet supplements, but only when taken as part of a proper diet and exercise program. On the other hand, diet supplements can cause a variety of side effects, such as: heart problems, increase risk of stroke , shortness of breath, fluid retention, inability to concentrate, shakiness, sleep problems, malnutrition, binge eating when diet supplement wears off, and rapid weight gain after you go off the supplements.

Herbal Diet Supplements - No More Effective for Weight Loss

Some claims about the supposed weight loss benefits of herbal weight loss supplements or "natural" fat-burners or appetite suppressants are even more misleading. Many of these herbal diet supplements are amphetamine-type stimulants, which theoretically increase the metabolism and help the body break down fat. Nevertheless, there is very little (if any) evidence that they are effective for weight loss. In addition, some diet supplements (e.g. those containing ephedra/ma huang) have been linked to serious side effects such as heart attacks, seizures, and death.

"Natural" Diet Supplements - "Herbal Phen-Fens" - Safety Not Guaranteed

Herbal phen-fens - named for their supposed weight-loss resemblance to the banned prescription drug combination of phentermine and fenfluramine - are by far the biggest sellers of herbal weight-loss supplements. The big difference, according to herbal phen-fen makers, is that unlike the prescription drug, herbal phen-fens are completely safe because they use "natural" ingredients. This is not true.

According to Dr. Kathy Kapica, PhD, RD, associate professor of nutrition and dietetics at Chicago Medical School:

"Some of the most potent toxins are ‘natural’...even poison is natural...the word ‘natural’ does not guarantee safety."

Diet Supplements - Labelling and Ingredients

Another major problem is that due to the lack of legal standards and FDA regulatory powers over herbal diet supplements, consumers can’t always be sure that the products they are getting are pure, or even contain what the labels say. Most herbal phen-fen supplements contain a mixture of herbs which often include ephedra, St. John’s wort, chromium picolinate and others. Some diet-supplement ingredients like ephedra, can be dangerous when abused, while others, such as St. John’s wort and chromium picolinate, show no clinical evidence of being beneficial for weight loss.

Diet Supplements - Bottom Line

  • Many diet supplements meet no proper safety or efficacy standards before or after hitting the marketplace. And inspection of supplements is limited.

  • Many diet supplements are ineffective for weight control. Weight loss studies have been conducted using specific ingredients found in many diet supplements, but most such studies were inadequate.

  • Labels on diet supplements are not always accurate. In one study, investigators found dosages were more than 50 percent higher than labeled.

  • Diet supplements may have unlisted ingredients. The International Olympic Committee found that of 634 nutrition products that it analyzed, 15 percent contained ingredients banned by the committee and were not listed on the supplement label.

  • Tighter Regulation of diet supplements is needed. Weight loss drugs may not be sold in the United States until they have been tested effective and certified safe. But diet supplements can, provided they contain ingredients already in the food supply. But since many diet supplements especially herbal "phen-fens" perform like drugs perhaps they should be classified as weight loss drugs not supplements.

Some Diet and Weight Loss Supplements Reviewed

Ephedra in Diet Supplements

Ephedra, also known as ma huang, is a strong stimulant found in popular "herbal phen-fen" weight loss supplements. While it relieves nasal congestion and some allergic disorders, Varro E. Tyler, an authority of the medicinal use of herbs, states: "there is no substantial clinical evidence that [ephedra] is either a safe or effective promoter of weight loss." And, ephedra can be very damaging to the body, especially when abused. When taken regularly in weight loss supplements, your body can stay in an unnaturally high gear and there is risk for heart palpitations, heart attacks, and strokes.

St. John’s Wort in Diet Supplements

Many herbal "phen-fen" supplements with ephedra contain St. John’s wort as well. Manufacturers of diet supplements containing St. John’s wort claim it may increase the production of the brain chemical serotonin, possibly having a positive influence on mental wellness, which could help suppress overeating that may be linked to depression. However, there is no clinical evidence to substantiate that St. John’s wort has weight loss benefits.

Chitosan in Diet Supplements

Sellers of this popular diet supplement tout its ability to "trap" and get rid of dietary fat and cholesterol. The theory is that when taken regularly, chitosan-a non-digestible dietary fiber-will decrease the absorption of fats and carry them, along with their calories, right out of the body. While there have been some promising studies that show chitosan to have a cholesterol-lowering effect in animals, there is absolutely no research indicating that chitosan is effective for weight loss in humans. In fact, Chitosan has the potential to be harmful due to the fact that it binds fat soluble vitamins, which could result in deficiencies and set in motion other harmful effects.

Chromium in Diet Supplements

The mineral chromium, found in tiny amounts in almost all foods, helps the body burn fat, build muscle, and control blood sugar. Sellers of chromium diet supplements claim that chromium pills are effective for weight loss but while a few studies have found that chromium supplements apparently lead to small gains in muscle and modest weight loss (as in roughly 2 pounds of fat lost per month), several recent studies have found no such effects.

Richard A. Anderson, lead scientist at the United States Department Of Agriculture's Beltsville Human Nutrition Research Center, has studied chromium supplements in many contexts over the last 20 years, and he's never seen the supplements change a person's body weight. He says:

"Chromium is only a small part of the puzzle in weight loss and body composition, and its effects, if present, will be small compared with those of exercise and a well-balanced diet."

Diet Supplements - Diuretics

Diet supplements that contain diuretics stimulate water-loss. If you take a diet supplement that makes you lose (say) 2 pints of water, your weight will decrease by about 2 pounds, but the moment you drink liquids, this water will be replaced in the body and you will regain your lost weight. Unless prescribed by a physician, diuretics are potentially harmful because certain diuretics increase potassium losses causing muscle weakness, including weakening of the heart muscle, and mental confusion.

Diet Supplements - Laxatives

Diet supplements that contain laxatives stimulate the digestive system and can cause severe diarrhoea. Any weight loss is likely to be water loss, not fat loss. If you are taking one of these products and find that you are constantly suffering from diarrhoea, then it is advisable to stop taking the diet supplement immediately as you may develop dehydration and vitamin and mineral deficiencies, all of which may have bad effects on health. In short, diet supplements that contain laxatives are not good for weight loss or health.

Diet Supplements, Herbal Pills - Be Sceptical of Impressive Weight Loss Claims

When buying diet supplements, be sceptical of claims of easy weight loss. If weight control was that easy, or fast, a major weight loss drug company (who spends millions researching weight control medications) would surely have produced such a miraculous weight loss supplement and all of us would know about it.


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