Justin Bieber, Pole Dancing Help A.J. Jacobs' Health Quest

'Drop Dead Healthy' documents journey to become healthiest person in the world, including 'the most physically painful thing I've ever done.'

First, he read all 32 volumes in the encyclopedia and wrote about it in "The Know-It-All." Next, he lived an entire year by the Bible and documented it "The Year of Living Biblically." Now, in "Drop Dead Healthy," A.J. Jacobs is chronicling his goal to become the healthiest person in the world.

The idea came to him three years ago when his wife told him he was in terrible shape. Self-described as "skinny-fat," he knew his next project would be a total health kick. "I had to transform every part of my body ... my diet, exercise, sleep, stress level, sex life, posture," the author recently told MTV News.

He started by seeking out medical experts' advice, then deciding what would work for him. Of course, it can be complicated choosing which advice to listen to and which to pass on, but Jacobs learned that there are four things nearly all medical experts agree on: "You need a lot of sleep, you need whole foods, move around — stop sitting, and keep your stress level low. If you keep those four things going, you're 90 percent there," he explained.

He also learned music is good for your health. One study he recalled involved putting subjects on a treadmill to record their speed to a sped-up version of a Justin Bieber song, and then again with a slowed-down version. The results showed subjects were much more likely to move faster when the music was faster — even without knowing it.

Having never been to a gym made for a challenging transition when he vowed to exercise every day. He got active in everything from aerobics, weight lifting and even taking to Central Park for a high-intensity "cave man" workout. "It was the most physically painful thing I've ever done. In the end, I'm glad I did it," he shared.

But the physical activity wasn't all just pain for Jacobs. As another means of getting into shape, he started attending the most-popular class at his gym: pole dancing. "I was the only guy, and there was about 50 women. If you are a single man, this is something you might want to consider as a workout option," he advised. "I was very impressed, because it takes a lot of upper-body strength, and it made me realize strippers really earn their tips."

The project gave Jacobs a new perspective on his life, giving him new habits he kept, even after the book went to print. "I try not to sit as much anymore," he said. "One doctor told me sitting is the new smoking."

It was that sort of advice that inspired him to get a treadmill in his house, and he wrote the entire book while walking — clocking in 1,200 miles, almost enough to walk from New York City to Chicago and back.

Regarding recent awareness campaigns like HBO's film series "Weight of the Nation" and New York City Mayor Michael Bloomberg's controversial proposed ban on large-sized sodas, Jacobs was supportive.

"I think any kind of information you can get out there is helpful, because it really is an obesity epidemic," he said. "The fact that two of three Americans are overweight is going to have a huge impact on everything — on our health care system, on people's life spans. Any small step you can do to stop this obesity epidemic is really crucial."

Ultimately, if there's going to be a change, Jacobs wants to see improvement in the schools. "There's only so much you can do with individual choice: It depends on what choices you have, and if you have no healthy options, there's no chance you can get any healthier."