Tiny Pills, Big Promises

Today’s dietary aids make silver bullet promises. But do they actually deliver, and are they really safe? At last, the straight-up answers you’ve been looking for.

Shortly after skeletal waifs started slinking down Europe’s catwalks, Hollywood’s bony A-listers crash dieted their way into microscopic frocks, and actress Jennifer Love Hewitt took center stage to defiantly declare that her size 2 frame is not “fat,” Tina Stottlemyer threw in the towel.

Nothing was working. With her bathroom scale glued at 175 pounds and the clock ticking down to her 20th high school reunion, the Pittsburgh mother of two began praying for a miracle.

She thought she found it in Hoodia gordonii, an appetite suppressant that boasted “miracle” powers, no side effects, and an easy payment plan. Stottlemyer did indeed see startling results—mostly unwelcome. “Everything I read about hoodia was so promising,” she reflects. “But in some ways, it made my diet roller coaster worse, not better.”

When people who are overweight seek help losing weight, nutritionists typically give the same textbook formula: Light meals + frequent exercise = weight loss.

The math seems obvious, but many folks discover that it just doesn’t add up. Some people can gorge on calorie-dense foods and stay rail thin. Others peck at their plates, exercise like Marines, and still watch their bodies balloon. Slowly and painstakingly, scientists are beginning to unravel this mystery but admit that a definitive answer may take years. In the meantime, millions of desperate Americans have turned for answers to the diet industry, spending money on products whose long-term effectiveness and safety are largely unknown.

What’s the skinny on diet drugs? Dietary aids rely on one of three basic strategies: Some try to suppress appetite, while others boost metabolism or block the absorption of fats and carbohydrates. Our experts discuss what they do—and what they don’t.

Strategy No. 1: Tame Your Hunger

Prescription appetite suppressants (also known as slimming pills) have been sold in America since shortly after World War II. Despite 50 years of research, just two prescription meds have FDA approval today: phentermine and Meridia. Hoodia gordonii, an over-the-counter (OTC) product, is also available but remains unproven. And even FDA approval is no guarantee. The two drugs that made up the Fen-Phen tandem—fenfluramine and phentermine—each earned FDA approval before they were combined into one medication that in the mid 1990s damaged the hearts of an estimated 30% of users.

Both phentermine and Meridia are reserved for clinically obese individuals with a body mass index of at least 30, which corresponds to a 5-foot 5-inch woman of 180 pounds. But with obesity so prevalent, physicians are prescribing these drugs off-label to even modestly overweight people.

Phentermine. When a drug forms the “phen” half of the disastrous Fen-Phen label, one would expect sluggish sales, but this amphetaminelike med still sells like buttery hotcakes. Almost 50 years old, phentermine doesn’t have the sex appeal of its glittery competition, but “it works, it’s relatively safe, and we know the side effects,” says Lawrence Cheskin, MD, director of the Johns Hopkins Weight Management Center. Still, users need to eat sensibly for life—and exercise, exercise, exercise.

Because phentermine is potentially addictive, it is FDA approved only to kick-start weight loss for six to eight weeks. But many physicians prescribe it off-label for longer periods. Arthur Frank, MD, director of the George Washington University Weight Management Program, calls it “a very good drug for long-term weight maintenance.”

Phentermine users lose an average of 10% of their body weight. That isn’t dramatic but will likely reduce a 210-pound woman’s risk of heart disease, diabetes, and stroke—and make her feel much better about herself. Adverse reactions are rare but include dry mouth, insomnia, irritability, and constipation. Users should also avoid alcohol.

Meridia. This appetite suppressant did gangbusters business when it first hit American shelves in 1997 thanks to a multimedia marketing blitz hailing it as the first FDA-approved drug for long-term weight maintenance. It continues to ride a crest of popularity. On Internet message boards, you’ll find Meridia fans singing—sometimes shouting—its praises.

But a University of Alberta study doesn’t paint so rosy a picture, noting that users lose just 9.2 pounds on average. Without regular exercise, they lose only 3.5 pounds, says manufacturer Abbott Laboratories.

Internet message boards contain plenty of posts from detractors, too. Many quit taking Meridia prematurely, either because of its budget-busting price or because headaches, dry mouth, and/or constipation were driving them nuts. In 2002, the watchdog group Public Citizen unsuccessfully lobbied to get Meridia banned, citing the substantially increased risk of higher blood pressure, increased pulse rate, arrhythmia, and sudden death. Still, many doctors consider it safe enough when carefully monitored.

Hoodia gordonii. In 2004, the CBS news program 60 Minutes introduced America to hoodia, telling viewers that South Africa’s skinny Bushmen chewed this bitter-tasting plant to ward off hunger on the Kalahari Desert. These days, late-night infomercials hawk hoodia as a “Stone-Age wonder plant.” Sales are soaring, but there’s no credible data to show that it is effective or safe, explaining why the scientific community accords it slightly less credibility than the Abominable Snowman. In 2005, a former hoodia researcher noted that early clinical trials showed it to be a potentially potent appetite suppressant but other “components might cause unwanted effects on the liver.”

Hoodia products are everywhere, from transdermal skin patches to hoodia lollipops.

At first, Stottlemyer counted herself a huge hoodia fan. “I lost 12 pounds in three months. I was so proud!” she declares. “But then my weight slowly came back, my ‘skinny clothes’ stopped fitting, and I got really, really depressed.” The good news? The former collegiate swimmer returned to the pool, got some dietary counseling, and has slimmed down to 155 pounds.

In the wake of skyrocketing demand, Botanic Gardens Conservation International reported in January 2008 that hoodia and some 400 other medicinal plants are at risk of extinction. “Vast quantities have been ripped from the wild. … Few [companies] will invest in planting the species as a commercial crop until its properties are proven,” the report said. What’s more, as demand outstrips supply, the market has become so flooded with counterfeit hoodia that it’s impossible to know whether your purchase is legit or bogus, safe or hazardous.

“Hoodia is a little mystical and it’s a natural herb, so people tend to think, ‘Oh, it must be good for me,’” says American Dietetic Association (ADA) spokesperson Susan Moores, RD. “But there’s no evidence that it works, and hoodia doesn’t do a thing to counter emotional or mindless eating.” Agreeing, Cheskin quips, “Bushmen may be thin, but they get a lot of physical activity, and they don’t eat junk food.”

Strategy No. 2: Burn It Off

Retooling the human body into a lean, mean, fat-burning machine is the iffy promise made by some metabolism boosters. By harnessing the fury of “thermogenic power,” claim advertisements, these products fire up your internal furnace and melt away blubber. In January 2007, the Federal Trade Commission disagreed, fining the makers of Xenadrine EFX, One A Day Weight Smart, CortiSlim, and TrimSpa for unsubstantiated claims.

Since the FDA banned high-dose ephedra in 2004 due to its abuse by adolescents, manufacturers have turned to gentler, so-called all-natural metabolism boosters: yerba mate, green tea extract, glucomannan (a yamlike fiber), country mallow (heartleaf), Caralluma fimbriata, Paulinia cupana (guarana) extract, pyruvate, Garcinia cambogia extract, and other polysyllabic tongue twisters. Some companies go for the diet trifecta by supercharging their products with a combo of “all-natural” metabolism boosters, appetite suppressants, and carb blockers.

But Consumer Reports cautions that all natural isn’t necessarily synonymous with good for you. Pairing bitter orange with caffeine, for instance, can cause a dangerous spike in blood pressure and heart rate. Consumer Reports’ list of “Twelve [Dietary] Supplements You Should Avoid” includes aristolochic acid (birthwort, snakeweed, sangree root, and wild ginger), comfrey (black root, blackwort, bruisewort, and wallwort), chaparral, germander, kava, bitter orange, lobelia, pennyroyal oil, scullcap, and yohimbe.

So-called functional coffee—ordinary joe spiked with an extra shot of caffeine, green tea extracts, niacin, and other stimulants—has recently bellied its way into the diet scene. One maker claims its concoction of bitter orange, hydroxycitric acid, and the heavy metal chromium can rev the human metabolism by up to 30%. Nothing credible substantiates these claims, but sales continue because federal regulation of supplements is lax.

“Only exercise will rev up your metabolism,” says Suzanne Farrell, MS, RD, a Denver-based weight management specialist and ADA spokesperson. “There is no quick fix or magic pill, and these supplements could have dangerous side effects.”

Cheskin agrees: “We haven’t gotten overweight because of a lack of bitter orange or caffeine or chromium in our diets.”

Strategy No. 3: Block Fat and Carbs

Xenical is the second of two prescription meds (along with Meridia) that are FDA approved for long-term weight loss, with a half-strength cousin sold over-the-counter cousin as alli. Both meds reduce your intestine’s ability to absorb fat. Much like Antabuse for alcoholics, these meds reward good behavior but punish indulgence with a vengeance.

Go ahead and devour those greasy buffalo wings if you take these meds, but do so knowing the aftermath could include “bowel urgency with poor control.” No wonder users are reminded to wear dark pants and keep a spare change of clothes on hand. Other symptoms of the dreaded “Xenical moment” include uncontrollable gas “with anal discharge,” abdominal cramping, and/or oily spotting of your undergarments. Worse yet, these can happen without warning—when you’re on a date, running down an airport terminal, or having a power lunch with a major client.

In addition, people taking fat blockers generally achieve only modest weight loss, losing on average just 6 pounds more than they would lose through diet and exercise alone after one year.

Carb blockers (or starch blockers or neutralizers) are another matter. UCLA researchers confirmed in April 2007 that a white kidney bean extract sold as Phase 2 does indeed help people burn off consumed starches more quickly, resulting in “lost body fat, not lean muscle.” But much more study is needed about long-term effectiveness and safety.

Carb blockers can have a downside. As an experiment, four moderators of the popular Web site 3FatChicks.com tested Phase 2 Carb Intercept in 2007. “Our results did not live up to the claims and had a surprising negative effect on our diet,” recalls Suzanne Barnett, who coauthored the book 3 Fat Chicks on a Diet: Because We’re All in It Together. Barnett’s group experienced side effects that included hypoglycemic episodes, abdominal pain, and heartburn. These symptoms largely disappeared within two weeks, but she notes, “I did feel zapped while taking Phase 2 … and none of us wanted to repeat the experiment. … What we’ve learned from our members on alli—and from our own experiment with Phase 2—is that, if you don’t want to digest [something], just don’t eat it.”

Farrell and Moores agree and say there’s no substitute for setting realistic goals and making healthy lifestyle changes. Extreme dieting, they say, often backfires. People who try to artificially dull their appetite, crank up their metabolism, and/or block fats and carbs often experience long-term weight gain.

“Lots of people want to lose that 5% in the first week,” Farrell says. “I tell my clients they need to allow three months for a 5% loss in weight and six months for a 10% loss.”

She reminds clients of this enduring truth: It wasn’t gained overnight, and it won’t be lost overnight either.

— Matthew Robb and Nancy Robb, RD