Seven years ago, while training as a Thai boxer, Marcus Antebi kept running up against the same roadblock: how to cut weight without sacrificing the fuel he needed for his vigorous workouts. A coach at his Queens gym offered the unlikely solution: Consume nothing but salad and juice.

Back then, Antebi says, only "one one-millionth" of people were eating that way. Today, juicers are everywhere. While gourmet juice bars have thrived on the crunchier West Coast for years, they're now cropping up in cities like Chicago and Boston. And last March saw the opening of the first Evolution Fresh, a new juice chain from Starbucks CEO Howard Schultz.

Antebi saw this day coming. Two years ago, he opened a jewel box of a shop, Juice Press, in New York's East Village, that sells organic juices along with typical bark-eater snacks like walnut-pâté sushi. The store has such a devout following, Antebi opened three more locations and has plans for expansion. You could call him an opportunist – one estimate claims U.S. juice-bar profits reached $2 billion in 2010 – but the 43-year-old Antebi is also a missionary, a guy whose life was changed by regular hits of leafy greens. "Ice cream and pasta Bolognese aren't comfort foods for me anymore," Antebi says. "In fact, they make me feel worse five minutes later."

Of course, juicing has had plenty of evangelists, from raw-food pioneer Norman Walker– who published his first book on the topic in 1936 – to workout guru Jack LaLanne, who shilled his Power Juicer in late-eighties infomercials. But over the past five to ten years, the practice has become the norm, even among people who don't wear hemp ponchos.

"It used to be kind of metrosexual for a guy to go, 'God, I'm craving kale right now,'" Antebi says, "But it's happening more and more."

In part, that's because juicing isn't just for cleanses anymore. These days, guys are reaching for fresh-squeezed juice packed with greens (not one of those fructose bombs from Jamba Juice) for lunch instead of their usual foot-long meatball sub. Even the website of Joe Cross – whose 2011 documentary Fat, Sick & Nearly Dead chronicled the 41-year-old's transformation from a ­310-pound schlub to a 230-pound picture of health via a 60-day juice-only diet – offers chewable dinner options alongside other recommended juice fasts.

"I prefer the idea of incorporating juice into your daily life rather than a juice cleanse – I see many people who cleanse and then overeat when it's done," says New York physician Frank Lipman. "As part of a good eating plan, it can induce weight loss, clear skin, improve digestion, and boost energy."

The science is simple: Most of the foods consumed in the modern Western diet – proteins, sugars, starches, and dairy – break down into highly acidic components when digested. The resulting inflammation manifests in a host of common problems: acne, fatigue, allergies, and moodiness, among others (many nutritionists cite inflammation as the basis for almost all diseases). But raw fruits and vegetables contain alkalizing minerals that restore the body's balance and soothe that internal irritation.

As to the criticism that juice lacks fiber: It does. But because fiber's main purpose, Antebi contends, is to help move dense materials through the digestive system, juicing renders it unnecessary. The liquid nutrition is absorbed into the bloodstream within minutes.

"When you drink juice, a machine did all the masticating for you," Antebi explains. "Broke up everything, took the nutrients out. You drink it, you're done. And you have more energy because there's less digestion. That's the main benefit, even on just one juice a day."

Matthew Barbee, a 35-year-old brewer in Ohio, is a recent convert. After four months on a regimen that includes an orange-carrot-ginger combo with breakfast, and one or two more juice snacks during the day, Barbee says he's lost weight and felt his spirits lift.

"I was hitting caffeine pretty hard in the morning, which would drop me, and I'd become really pissy," Barbee says. "But when I juice in the morning, I'm in a better mood."

Antebi has even convinced New York Yankees first baseman Mark Teixeira, working with the slugger on an off-season program that helped him shed 15 pounds – and prompted him to invest in Juice Press.

"I just wanted to be a little healthier and have more energy," Teixeira says. "But the weight just melted off, literally. That's going to make me quicker over a long season."

Purists maintain that real benefits only accompany 100 percent organic, unprocessed juice (most bottled brands are pasteurized, which kills active enzymes, and laced with added sugars and preservatives). Bonus points if it's been cold-pressed, a process that crushes ingredients without blades, keeping the juice free of air molecules that would otherwise kick-start decomposition. But the real key, according to Antebi, is that a decision to drink juice, whether it's for one meal or three, is a decision not to put processed crap into your body.

"People believe that I have the secret formula," Antebi says. "That's not the case at all. The simple fact that a person is abstaining from garbage and drinking something nutrient-rich – that's why they're getting a health benefit."

More information: Try some juice press bestsellers in a home juicer (try a Hurom, Green Star, or Breville), playing with the ratios till they taste right for you. Just go easy on ginger, herbs, and spices, which can overpower your drink. The Complete Source contains carrot, celery, spinach, and parsley. The Spicy Citrus has chunks of grapefruit, orange, and lemon (with rind), ginger, and a pinch of cayenne. Lastly, the Doctor is made with chopped red apple and pineapple, kale, lemon, and ginger.