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Cycling Nutrition with Monique Ryan: The danger of weight loss supplements

This past May the Food and Drug Administration (FDA) moved to ban the diet product Hydroxycut after receiving 23 reports of serious health problems related to the product, including one death due to liver failure.

Consumers should be aware that despite the fact that the FDA has strong and sweeping powers to ensure the safety of drugs through its approval process, it has limited control over the “dietary supplement” industry. The FDA is limited to waiting until people actually die or risk unreasonable risk or injury before the law permits it to inspect or ban a dietary supplement product.

Many weight loss supplements similar to Hydroxycut may still be on the market.

Hydroxycut, which sold over 9 million units last year, has agreed to recall 14 of their products including Hydroxycut Liquid Shots and Hydroxycut Carb Control. Products containing Hydroxycut Cleanse and Hoodia are not affected by the recall. The most recently recalled products contain a variety of ingredients and herbal extracts and the FDA has not yet determined which ingredients, dosages, and other factors may be related to risk with these products.

What’s the lesson here?

Buyers should beware of dietary supplements that incorporate a variety of ingredients and herbal products used in various combinations, and which make strong claims, particularly around weight loss and fat burning.

Many weight loss supplements similar to Hydroxycut may still be on the market and their multiple ingredient lists bear more scrutiny and skepticism than the more familiar ingredients seen in a standard type of multivitamin product.

Because weight loss supplements of any type are classified as dietary supplements not drugs, their individual and ingredient combinations are not evaluated and approved by the FDA prior to being put on the market. These products are available at supplement stores and even grocery stores and often are heavily advertised. While it might be tempting to reach for such a product to drop the last few pounds for the season, proceed with caution.

It is estimated that 15 percent of Americans use diet supplement to boost weight loss, choosing products that promise to limit appetite, block fat absorption, and increase metabolism. Retail sales of weight loss supplements were estimated to be more than $1.3 billion as far back as 2001, with an ephedra-containing product topping the list.

Claims can be enticing. In 2007 the Federal Trade Commission (FTC) settled with marketers of four diet pills, including Xenadrine EFX, CortiSlim, TrimSpa, and One-A-Day Weight Smart, who paid fines and agreed to limit future advertising claims. A weight-loss product is likely too good to be true if it claims a weight loss of two pounds weekly or more without diet or exercise, a significant weight loss no matter what you eat, or permanent weight loss.

In truth, very few ingredients have been proven to promote weight loss, and while there is preliminary data for a few products, there is clearly no such thing as a miracle fat-burning product. Often there is limited safety data, and studies often look at the effects of a single ingredient, not the possibly synergistic multiple ingredients often seen in weight loss products, whether weight-loss producing or potentially harmful. Purported mechanisms and some ingredients which fall under these categories are listed below, along with a few comments on some of these supplements:

Increase energy expenditure

Caffeine, ephedra, bitter orange, guarana, country mallow, yerba mate

While ephedra has been banned because of documented safety concerns, some of these other products can also have side effects similar to a caffeine overdose, including increased heart rate, restlessness, and anxiety and are often combined with caffeine in various products.

Increase fat oxidation or reduce fat synthesis

l-carnitine, hydrocitric acid, ECGC found in green tea, vitamin B5, licorice, conjugated linolenic acid, pyruvate

Epigallocatechin or ECGC, the polyphenol in green tea, is currently being studied for fat-burning effects. Some ECGC study results for increased fat burning look promising, though subjects were not trained athletes and more research is needed. While labels do not contain warnings at this time, the United States Pharmacopia (USP) continues to monitor the safety of green tea supplements which have been associated with liver toxicity, so stick with green tea drinks.

Conjugated linolenic acid is also undergoing some scientific study. One study found that 3.5 grams daily taken for one year produced decreases in body fat when compared to a placebo. However, there is also evidence that it may increase some risk factors for cardiovascular disease. Overall, research findings are inconsistent and varied with the type of CLA product used.

Data to support l-carnitine and pyruvate as weight loss supplements is weak.

Modulate carbohydrate metabolism

Chromium and ginseng

Well-designed research has not supported the claims that chromium builds lean mass and decreases body fat.

Increase satiety

Guar Gum and psyllium

Although guar gum is relatively safe, a review of a number of studies found no weight loss benefits.

Block dietary fat absorption


Chtiosan is an indigestible fiber made from the shells of shellfish. Studies do not support that it blocks fat and use can lead to GI side effects. Beware if you have a shellfish allergy.

Increase water elimination

Dandelion and cascara

Cascara acts as a laxative and could cause adverse effects with long-term use.

A better approach to weight loss

Losing weight can be hard work, but there are many safe ways to modify your food intake and decrease calories for slow and steady weight loss.

It is probably best at this time in the season to not cut back on calories around training, unless it is an easy ride, so as not the compromise fueling during harder rides and recovery nutrition. Check on your weight regularly and catch diet slip-ups before they become weight plateaus or regains. Try to eat similarly on weekdays and weekends, and not make Saturday and Sunday “free food” eating days, though your energy needs may increase somewhat with longer rides.

Eating breakfast and regular meals and snacks also provides your body with a steady supply of fuel. Pay attention to hunger and eat on time, eating when you are ravenous often leads to overeating. Pay attention to fullness as well, and push away the plate when you are comfortably full. One effective strategy for cutting back on calories includes eating high volume, high fiber foods, namely more fruits and vegetables. This helps you to feel full on fewer calories.

Of course mindless eating is what gets many of us into trouble. Portion sizes are powerful mindless offenders in our culture, whether at home, restaurants, or at the movies. Pay attention to what you serve or what is being served and cut back slightly. Look at what and how much you eat and identify your diet danger zones such as snacking, large dinners, or mega-portion coffee-hourmcarbohydrate. Small changes can shave off 200 to 350 calories per day and result in some weight loss. For example, snacking on a piece of high fiber fruit like an apple rather than a scone or muffin, can result in a savings of several hundred calories.

Effective, season-long weight management is likely to derive from sensible habit change, and while it may not be as enticing as the claims around weight-loss supplements, it does work and is certainly safe.

Monique Ryan, MS, RD, LDN is a nationally recognized nutritionist with over twenty-four years of experience and is owner of Personal Nutrition Designs, a Chicago based nutrition consulting company that provides nutrition programs for endurance athletes across North America (www.moniqueryan.com).

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