'The 4-Hour Body'—Does It Deliver Results?

Experts aren't so sure the claims in this best-selling book hold water.

By + More

We love quick fixes. When it comes to diet and exercise in particular, the faster we're promised we can drop 20 pounds and uncover that six pack, the better. Unfortunately, many of our efforts seem to fall short (at best, right?). Enter: Timothy Ferriss and his book, The 4-Hour Body.

Want to gain 34 pounds of muscle in 28 days for a Hulk-esque chiseled chest? Ferriss says he did it. How about dodging fat gain while bingeing on 6,000 delicious calories in 12 hours? Ferriss says it's possible, and he's eager to tell you how he did it. In a span of 10 years, this human guinea pig—who also wrote The 4-Hour Workweek—documented these and other seemingly impossible physiological feats. The result is a book that for months has dominated the Amazon and New York Times bestseller lists. Though much of Ferriss' evidence comes only from small studies, personal experiments, or isolated case reports, he says he knows the secrets to "rapid fat-loss, incredible sex, and becoming superhuman." Can he back up his claims? More importantly, will they work for you? Experts have their doubts.

Claim 1: You can lose 20 pounds in 30 days without exercise.

How? Ferriss forbids many of our favorite carbs, including all bread, rice (white or brown), cereal, potatoes, pasta, tortillas, and fried food with breading. Anything else white is also off limits. You can't drink any calories and must stay away from fruit. But you can eat as much protein, legumes, and non-starchy vegetables as you want. Ferriss advises finding a few acceptable meals and eating them over and over. Effectiveness—not fun—is the No. 1 priority here, he writes. You are allowed one cheat day each week, though. That's not just a snack or meal, but an entire day of cheating. Because you've denied your body lots of calories throughout the week, a binge day ensures your metabolic rate doesn't "downshift," Ferriss explains. (He's binged on 6,000 calories in 12 hours, while using a cocktail of obscure supplements and strategic muscle contractions to try to minimize fat gain.)

Experts say: To Scott Kahan, codirector of the George Washington University Weight Management Program in Washington, D.C., it all "sounds like another cockamamie fad diet." Sure you're likely going to lose quite a bit of weight quickly by cutting carbs, he says, but then what? Never eat another piece of bread? "There needs to be something reasonable after that," he says. "There needs to be some sort of sustainable way of going about the rest of your life." While some "cheating" can make a diet more sustainable by giving you a break, says Kahan, a binge isn't the answer, and the supplements Ferriss recommends—like garlic extract—haven't passed rigorous scientific muster. Still, Ferriss stands by the diet. He says he and hundreds of other longtime adherents have lost weight and seen improvements in their cholesterol and triglyceride levels.

[8 Ways to Stick to Your Diet While Friends Indulge]

Claim 2: You can function well on only two hours of sleep a day.

How? It involves taking six 20-minute naps, spaced evenly over a 24-hour period. Ferriss admits he reserves this method, a version of what's known as "polyphasic sleep," only for meeting emergency deadlines. So Dustin Curtis, credited simply as an "experienced polyphasic sleeper," served as Ferriss' go-to source on the approach. Most people sleep eight hours a night, Curtis says, but spend only about two hours in so-called rapid eye movement (REM) sleep. Because non-REM sleep is just "unnecessary unconsciousness," says Curtis, polyphasic sleepers "train" their brain to go right into REM sleep during each nap. Over 24 hours, he claims they amass two hours' worth of REM, about the same amount a normal sleeper gets during a full night's rest.

Experts say: So can you really function just as well on two hours of sleep? "The short answer is, if I may speak in medical terms, hell no," says Matt Bianchi, a neurologist and sleep physician at Massachusetts General Hospital in Boston. To say non-REM sleep is unnecessary is "foundationless," says Bianchi. "I would challenge anyone to come up with a sliver of data to support that." Consistently depriving yourself of sleep will hurt your body in some way, be it through heart or brain problems, he says.