Rick Rubin
Credit: Photograph by Howard Schatz

Hey, man, cancel everything. We're hanging with Rick Rubin tonight. You know Rick, right? No? Check your iTunes playlist. Kid Rock. LL Cool J. Metallica. Jay-Z. All Rick's audio kids. He once had Tom Petty write songs using refrigerator-magnet words! Dude is Phil Spector minus the fright wig and the .38.

Rubin has won seven Grammys, resuscitated Johnny Cash's career, and has somehow gotten three number one records for a bunch of Armenian-American art metalheads. Man's a genius for that one alone. Tonight, System of a Down – said Armenian metalheads – are headlining at the Forum in Los Angeles. Rubin wants to see his old friends, so we're going. This is a big deal. Rubin, who is 48, doesn't leave his Malibu pleasure dome very often, but he's putting it into gear for SOAD.

Instructions are texted. Be downstairs at 5:30. No, make that 6:30. Check that. 7:15. Still waiting. Out front, a sailboat bobs in the sea as the sun sets over the Pacific. Two minutes away, promise. A white Range Rover finally arrives, and a surfer Santa pops out. His skin is the color of cinnamon, the spice he likes to sprinkle on his organic apples. He speaks in a soft, dreamy indoor voice.

"Hi, I'm Rick. I'm going to ride in the back with you."

The beard doesn't surprise. Rick Rubin's undulating face hair is just as famous as his body of work. In homage to the yogis he read about as a boy on Long Island, Rubin hasn't shaved since he was 23. It's long been his registered trademark.

The rest of his getup does surprise. He's wearing a white T-shirt, Technicolor slip-on sandals, and skimpy black gym shorts. Actually, skimpy isn't the right word. More like genital-hugging. An intriguing choice for a man who moonlights as co-chairman of Columbia Records.

But something is missing. Something big. Something that is as much a part of Rick Rubin as his decadelong partnership with Johnny Cash, his nurturing of the Beastie Boys, his chocolate-in-my-peanut-butter meshing of Aerosmith and Run-DMC.

What's missing is half of Rick Rubin. When he used to listen to music, he would clasp his hands in front of him, his pasty arms barely reaching around his Buddha belly. But now as we talk, the same gesture looks storklike, ­like Gandhi before lunch. He's got too much arm and not enough girth. What happened?

Rick Rubin dropped 130 pounds in 15 months. How it happened will amaze, inspire, and freak you the fuck out.

He swears he didn't lose the best part of him.

It's not like Rick Rubin has been scarfing down White Castles for the past two decades. Okay, he did that as a kid. He also consumed 64 ounces of Pepsi with every meal, but that was a long time ago. Rubin was a vegan from age 23 to 46.

Before that, he says, "I wasn't eating anything except chicken and vegetables." Then a friend gave him the vegan bible Diet for a New America and predicted that he would never eat meat again.

Over the next couple of decades, he didn't eat meat, but Rick Rubin got up to 320 pounds. Some of that was genetics. Some of it was a lack of exercise. (Rubin always took the elevator.) And some of it was a profound misinterpretation of the vegan approach. Dave the Driver steers us onto I-10 while his boss speaks in a soft voice. "I used to eat tons of almond butter. I thought that was good for me. It turns out it's very high in caloric content."

Indeed it is: 190 calories a serving, 150 from fat. I want to ask who told him that eating large amounts of almond butter was good for him, but Rick interrupts.

"Dave, can I have a protein shake?"

We're late, so Dave is passing cars at 75. He flips open a cooler and hands Rick a plastic cup. He gives it a shake.

"Love these. Lots of protein. Egg whites, a little stevia, and Teeccino for taste."

I've heard of one of the ingredients.

Rick takes a sip and lets out a contented sigh. "I drink seven of these a day, so I'm never hungry. Sometimes I'll add some blackberries. That's good fruit. I avoid bananas and pineapples. They're too high in sucrose."

Dave jumps a curb and we're in the parking lot. Rick is so serene he notices no bumps. For years, he also didn't notice his expanding waistline. He produced the last six Red Hot Chili Peppers records, and over time hard-partyers-turned-health-nuts Flea and Anthony Kiedis began suggesting Rick might want to see a doctor and take the occasional walk. But his health kick didn't start until a scared-straight lunch with one of his heroes, legendary record executive Mo Ostin, who told him he was going to die if he didn't change his ways. Rick promised his 84-year-old friend he'd try to treat himself better. Immediately, he started researching diets.

"I just started eating meat again," Rick explains. "And eggs. When you're vegan, you spend your time chasing protein, and you're eating food that's way too high in carbs. I could never catch up on protein."

We're at the wrong entrance. Dave executes a perfect three-point turn, burning rubber and scattering the guys hawking bootleg System of a Down T-shirts on the median. Rick's eyelids don't even flutter.

Rick's meat has to be masked. His cook makes a turkey chili in which you can't even taste the turkey. He talks about eating meat as if he's reintroduced eight balls into his life.

"I'm trying red meat," he confides. "Very traumatic. I've done it four times. Very small amounts. It takes a while before you get over the idea that eating flesh is not okay."

Dave pulls onto the arena's loading ramp. Dudes in yellow windbreakers wave us in. Rick opens the door. Dave pipes up.

"Rick, you want a protein bar?"

"No, maybe later."

We enter the Forum. Rick's few remaining locks are sun-bleached and flow behind him like Misty of Chincoteague's mane. We sprint toward the side of the stage. Rick has also produced the opening band, Gogol Bordello. It's their last song, just enough time for Rick to move to the side of the stage where the guys can see him. Rubin closes his eyes and bobs gently. The Bordellos smile and hug him before the last chord fades.

Then we're in the bowels of the arena. In one dressing room, there are still basketball diagrams on the wall from when the "Showtime" Lakers played. Magic and Kareem stood right here. Now it's the private court of Serj Tankian, System of a Down's lead singer. Rick sees Serj and does a little Buddhist bow.

Serj has a tug of chin hair, but he's lost the Armenia-fro and cape from the band's 2001 heyday, replacing them with a Clooney cut and a crisp white shirt.

"Rick, you look great," he says.

Rick smiles.

"How are things?" Rick asks.

"Good, everyone seems to be getting along."

Rick nods.

"Just enjoy the moment."

Serj also nods, and his eyes light up.

"Hey, I've been doing those morning meditation exercises before I get out of bed."

"Yeah, aren't they great?"

Soon we split for the parking lot. There's a secret knock, and we're admitted on guitarist Daron Malakian's magic bus. The vibe is a little different.

"Smells like skunk in here," Rick jokes.

Daron laughs.

"Yeah, we're getting ready for the show."

A hanger-on chimes in.

"This is the least high I've seen you all week."

Daron rolls his bloodshot eyes.

"Really? I've been getting baked from the moment I woke up."

"Just enjoy the moment," Rick tells him. "I hear everyone is getting along."

Daron shrugs and places a black top hat on his head.

"I guess so. Serj is by himself in his mood room, right?"

Rick smiles but reveals nothing.

Someone shouts."Time to walk!"

So we walk, a haze of weed behind us. We're back in the bowels. There's a Spinal Tap wrong turn and we're in another holding room where roadies roll joints in front of Armenian grandmas. Trailing behind us, a fan says, "That's Rick Rubin!" Someone else shouts, "No fucking way. Rubin is fat."

In five minutes, we're cruising toward Malibu. Rick asks Dave to flip the satellite radio to a Big Band station.

It's getting late. Well, actually it's only 10:40, but in Rick Rubin's brave new world, that means closing time. He used to stay up until 5 am and then sleep until two.

"I hated the sun, and I loved sleeping through the conflict part of the day."

But then a performance coach (yes, he employs such a person) told him that wasn't natural for humans. Rick now believes the optimum waking time is the first three hours after the sun comes up.

"Now I live the athlete's schedule. You don't need to be up all night to be creative."

We pull up to my hotel.

"Okay, so I'll see you at 8:30 and you can see my workout routine. It goes up to 11 am and then we can do some pool work. Then we can grab some breakfast, and maybe we'll go paddle-surfing, and then we can talk and listen to some music."

I'm exhausted just listening. I get out of the car. Rick Rubin moves, pantherlike, into the front seat, and the Rover takes off. You heard me. Rick Rubin moved just like a panther.