The allure of miracle weight loss pills

Despite the NIH weight loss guidelines that recommend calorie cutting, increased physical activity and behavior therapy, many people are attracted to the ease and convenience (and purported effectiveness) of a miracle weight loss pill, typically supplements found in health food stores, the supplement aisles at supermarkets, multilevel marketing scams, and products heavily advertised on the Internet. Diet supplements are especially attractive because they can be bought over the counter or online without a visit to a health care provider, who would likely reiterate the NIH weight loss guidelines and/or prescribe a weight loss drug that would require regular follow ups (most people do not want repeated visits to their doctor).

Do wow-worthy weight loss claims have merit?

According to Darrell Hulisz, PharmD, associate professor in the Department of Family Medicine at Case Western Reserve University School of Medicine in Cleveland, Ohio and Karen Lindberg, PharmD, staff pharmacist for Rite Aid Pharmacy in North Canton, Ohio, over-the-counter weight loss products are aggressively marketed to the public and the manufacturers’ claims that the supplements will produce significant weight loss (among other alluring claims, like beauty, energy, and youth) without any unwanted side effects are especially appealing. Yet, many of the ingredients have never undergone rigorous scientific testing, and claims about their effectiveness are often misleading.

Hulisz and Lindberg say in light of scientific and public scrutiny as well as reported side effects, supplement manufacturers are struggling to bring weight loss products to the market that are both safe and effective. Regardless, there are still a lot of wow-worthy claims that simply have no merit. Hulisz and Lindberg have reviewed the most popular weight loss supplements and present the following information on weight loss claims, product safety and actual effectiveness.

Popular Weight Loss Supplements

Orlistat

According to Hulisz and Lindberg, Orlistat is the only FDA-approved over-the-counter medication currently approved for weight loss. The drug selectively inhibits gastrointestinal and pancreatic lipase activity, resulting in a 25 percent to 33 percent reduction of dietary fat absorption.

Orlistat has been available by prescription in a dose of 120 millgrams, marketed as Xenical, and it was recently approved in a 60-milligram dose, marketed as Alli for over the counter purchase. One 60-milligram capsule of Alli is recommended three times daily with meals or shortly after. In addition, the manufacturer suggests a reduced-calorie diet, smaller meal portions, and a maximum of 15 grams of fat per meal.

Side effects are minimal and are most often due to fat consumption exceeding 15 grams per meal. The 120-mg dose is well-supported by evidence, and the Alli Web site boasts similar efficacy and fewer side effects than Xenical. However, studies to support the half-strength dose are difficult to find. Regardless, many consumers report satisfaction and weight loss.

Recommendation: Hulisk and Lindberg recommend nonprescription orlistat as an adjunct to a diet low in saturated fat. However, expect only modest weight reductions of, on average, only about five percent of initial body weight. Also, if you exceed a daily intake of 30 percent dietary fat, you are more likely to experience gastrointestinal side effects.

Bitter Orange

Bitter orange or citrus aurantium comes from the sour orange plant, also known as the Seville orange, or zhi shi. Bitter orange contains synephrine, a substance that has effects similar to ephedra. Bitter orange has become more commonly used in dietary supplements since ephedra was withdrawn from the market due to adverse side effects.

Studies have shown modest weight and fat loss results (with 975-milligram doses combined with caffeine) but also increases in blood pressure and heart rate (for up to five hours after one 900-milligram dose of bitter orange). There have also been cases of ischemic colitis, angina, and possible myocardial infarction after using bitter orange for weight loss (however, these last cases occurred in people over 50 years old).

Recommendation: Hulisz and Lindberg suggest that despite the evidence supporting bitter orange as an effective weight loss aid, people should probably avoid it, especially people with a history of cardiovascular disease.

Chitosan

Chitosan is a derivative of a chitin found in shells of invertebrates, such as crabs and shrimp. It is touted as a "fat blocker” but there are no clinical studies that support these claims. However, there are also no reports of significant side effects.

Recommendation: Hulisz and Lindberg recommend not wasting your money on chitosan.

Chromium Picolinate

Chromium is a trace element that has a role in carbohydrate and lipid metabolism in the body. Research has shown that chromium supplementation, for the most part, does not result in significant decreases in weight or body fat. Further, high doses of chromium picolinate can result in toxicity.

Recommendation: Hulisz and Lindberg say, “Chromium picolinate is a trace element that works as a cofactor for insulin secretion. While this supplement is often studied in combination with other nutrients, few studies support its use as a weight loss aid.”

Conjugated Linoleic Acid

Commonly known as CLA, this supplement is a naturally occurring polyunsaturated fatty acid and is essential for the delivery of dietary fat and glucose into cells.

Research suggests that CLA does not result in significant weight loss nor does it have adverse side effects. However, one study reported that participants who took CLA had greater feelings of fullness after eating as compared to participants who took a placebo.

Recommendation: Hulisz and Lindberg say that evidence is lacking to support CLA for weight loss but that it may help attenuate weight gain in people who have a CLA deficiency.

Fiber

Although dietary fiber has long been thought to increase satiety, Hulisz and Lindberg say there is actually little evidence to support this claim. However, there is supporting research that suggests that fiber can reduce feelings of hunger and possibly result in weight loss.

Recommendation: Hulisz and Lindberg say that the average Western diet is relatively low in fiber and that there are health-related reasons to increase fiber intake but that people should not take fiber for the sole purpose of losing weight. Further, excessive fiber intake may result in loose stools, intestinal cramps, and bloating. For more information, read Understanding fiber.

Green Tea (Camellia sinensis)

Green tea extract is made up of polyphenols (flavanols or catechins) that are thought to be responsible for its claimed benefit in weight loss. Studies suggest that green tea alone does not result in significant weight loss or alter glucose or lipid metabolism. In fact, one study reported that participants with high caffeine consumption were actually more likely to gain weight than participants with low caffeine intake.

Recommendation: Hulisz and Lindberg warn that commercially available green tea products contain varying amounts of caffeine and that caffeine exhibits a mild diuretic effect, which can be perceived as weight loss, but is really only a transient loss of sodium and water. There are other health benefits associated with green tea so it is best to consume green tea in moderation and not for the purpose of losing weight.

Guar Gum (Cyamopsis tetragonolobus)

Guar gum is a soluble dietary fiber derived from the Indian cluster bean. Research indicates that guar gum does not alter satiety hormones or feelings of fullness. Guar gum has also been associated with gastrointestinal-related side effects, including flatulence, diarrhea, and nausea.

Recommendation: Hulisz and Lindberg say that while guar gum is a suitable source of soluble dietary fiber, there is insufficient evidence to recommend it as a weight loss aid.

Guarana (Paullinia cupana)

Guarana is native to Brazil and Venezuela and contains caffeine, tannins, resins, lipids, saponin, starch, and coloring agents. Guarana has been studied mostly as part of an herbal blend of various natural products, some including Ma Huang, which contains ephedra (which has been taken off the market for adverse side effects).

Research does suggest that guarana is associated with significant weight loss, but studies have looked at guarana combined with other substances. So it is unknown if weight loss occurs due to the guarana, the other substances, or the combination. Further, a number of adverse events have been reported with guarana, including irritability, heart palpitations, anxiety, and other central nervous system events.

Recommendation: Hulisz and Lindberg recommend avoiding this supplement because of the lack of guarana-only studies and because of the reports of adverse central nervous system effects.

Hoodia

Hoodia, one of the most popular natural nonprescription weight loss aids on the market, is a genus that comprises 13 species, including Hoodia gordonii, which is touted for having weight-loss properties (read Does hoodia really help you lose weight?). Hoodia is a flowering succulent derived from a South African bush and is described as cactiform, resembling the unrelated cactus family.

Claims about hoodia include suppression of the appetite center in the hypothalamus and the attractive absence of stimulant properties (which result in increases in blood pressure and anxiety). Though there are a number of unpublished studies touting weight loss success with hoodia, there is little scientific research to support weight loss claims.

Recommendation: Hoodia may be the most popular natural nonprescription weight loss aid currently marketed but there is little evidence in the medical literature to support recommending it.

Hydroxycitric Acid (Garcinia cambogia)

Makers of hydroxycitric acid supplements claim that it accelerates fat burning. It is derived from the rind of Garcinia cambogia, a fruit native to India.

Research suggests that hydroxycitric acid does not lead to significant weight loss when compared to placebo (in dosages ranging from 300 milligrams to 3000 milligrams) and that, regardless of effectiveness, only a few mild gastrointestinal side effects have been reported.

Recommendation: Hulisz and Lindberg say, “Hydroxycitric acid appears to be safe, but proof of efficacy for weight loss in humans is lacking. More studies are needed prior to recommending this supplement.”

White Kidney Bean Extract (Phaseolus vulgaris)

White kidney bean extract is marketed as a "carb blocker" that reduces the rate at which starch is converted to sugar in the digestive process and, ultimately, reducing caloric intake.

Research indicates that white kidney bean extract may decrease triglycerides and result in minimal weight loss, but not with statistical significance. However, one study has shown significant decrease in body mass index.

Recommendation: Hulisz and Lindberg explain that white kidney bean extract inhibits the activity of the digestive enzyme alpha amylase and that this results in the delay or attenuation of the absorption of starch and carbohydrates in the digestive tract. White kidney bean extract may be effective and no side effects have been reported.

Bottom Line

Despite being heavily marketed with irresistible claims of weight loss, most dietary supplements are not supported with scientific evidence. Hulisz and Lindberg say, “Lifestyle modifications, such as caloric restriction and exercise, should always be the first-line treatment for obesity.” They do, however, recognize that the claims and resulting popularity of nonprescription weight loss aids are appealing to people trying to lose weight.

They recommend informing your health care provider of any dietary supplements you are taking and to be aware of potential risks and the unsupported benefits of over-the-counter weight loss supplements. Keep in mind that just because something is sold without a prescription does not mean it is safe.

There is no miracle cure for obesity. If you are striving for long-term, effective (and safe) weight loss, your best bet is to follow a healthy lifestyle, get regular physical activity, and reduce the number of calories you eat while making sure you eat a balanced diet.

Be sure to visit the SheKnows.com Health and Wellness Channel to read many other articles on healthy weight loss, exercise, and more. For more information on these supplements and others, visit Medscape.com.