Dwayne De Rosario, right, has helped teach healthy eating habits to his D.C. United teammates. (Toni L. Sandys/THE WASHINGTON POST)

Dwayne De Rosario’s influence with D.C. United is measured in goals and assists and in his ability to coordinate the attack. It’s seen in his mentoring of a young roster and in his resolve to steer the club into the MLS playoffs for the first time in five years.

His sway is evident in another area: United is eating more fish.

“If we have salmon kabobs and steak kabobs, people are picking up all the salmon before the steak,” defender Ethan White said. “The way he eats, it’s rubbing off on us.”

MLS’s 2011 most valuable player is United’s most valuable eater. He sets the bar for soccer excellence — and then heads to the salad bar.

De Rosario, who will turn 34 next month, hasn’t consumed meat nor poultry in 20 years. He was vegan — no animal products whatsoever — for about 10 years before reintroducing fish into his diet in 2003.

“At my age, I need a certain level of fitness to keep up with the 21-year-olds,” the Canadian midfielder-forward said. “Being conscious of what you’re putting into your body is my main thing. You’re not eating just to eat; you’re eating because it has nutrients and you need it.”

Influenced by his West Indies roots and Rastafarian tenets that he embraced as a teenager, De Rosario eats a wide variety of natural foods. The core of his diet is “provisions” — root vegetables and fruits.

Soda and sugary beverages are out. Instead, he blends fruit smoothies and drinks coconut water and coconut and almond milk. On his Web site, derounited.com, he offers recipes for grilled tuna teriyaki with spinach salad and oatmeal with fruit.

“People look at me and say, ‘Wow, I can’t believe you’re a professional athlete and you eat like that,’ ” he said. “People have been eating like this for thousands of years. You start to integrate it into what you are eating and you think, ‘I can live off this and sustain a healthy and strong lifestyle.’ ”

The phrase De Rosario repeats is “going directly to the source” for nutrients.

Such eating habits are uncommon among pro athletes, who typically rely on meat and poultry for primary sources of protein. Those who have sworn off animal proteins compete mainly in individual sports, such as running and martial arts.

Olympic hero Carl Lewis and Pat Neshek, a veteran pitcher in the Baltimore Orioles organization, are vegan. So is Wade Barrett, De Rosario’s former teammate in Houston and now a Dynamo assistant coach. NFL tight end Tony Gonzalez experimented with a vegan diet before returning to small amounts of meat and chicken.

“I love it, but I don’t have the discipline,” United Coach Ben Olsen said. “He’s always taking care of his body. He is a great role model in how to look after yourself.”

De Rosario was brought up in Scarborough, a section of Toronto with a mosaic of immigrant cultures. His parents arrived in the 1970s from Guyana, a small nation on South America’s northern coast, and settled in a West Indian neighborhood.

Meat was considered a weekend food. De Rosario suffered allergic reactions to dairy products, and at age 14 he discovered he was lactose intolerant. More careful about his diet, “I starting reading and researching about organics,” he said. “You go to a natural grocery store and you learn there is a whole new world out there.”

Older brothers Paul and Mark were vegetarian, so he followed suit.

Their father, however, “doesn’t want to see a vegetable on his plate,” he laughed. “He’s slowly coming around.”

His father Tony’s influence came in the form of spirituality and music. Bob Marley and Dennis Brown records filled the house. De Rosario read about the Rastafarian movement, “what they stood for and the eating habits. The community around us had a lot of Rastafari. You talk and reason, talk about food.”

A few years into his MLS career, after tearing a knee ligament, a doctor recommended adding fish oils to improve his health. The vegan phase ended, but he remained faithful to the natural food path.

At their home in Bethesda, his wife Brandy and their four children, ranging in age from newborn to 14, follow similar diets. For the children, “it’s just keeping a balance and building a foundation,” he said. “When they get older and say they want to try meat, that’s their choice.”

Eating out typically takes them to Indian and Vietnamese restaurants and a juice bar. He’s still searching for a good Caribbean place.

A few weeks ago, when De Rosario’s mother Carol visited, she stirred up his favorite dish: metemgee, a Guyanese stew typically prepared with plantain, yam, okra, coconut and salt fish.

De Rosario uses Twitter to share his meal selections. Last July, before a match at San Jose, he wrote: “Game day. Water, porridge, fruit to start my day jus right.”

White, his teammate, retweeted it and added: “Porridge? Such a grandpa.”

That night, De Rosario scored twice in a nine-minute span.

A week later, before a game against Toronto, White tweeted: “Uh oh #dcu fans @dwaynederosario ate his porridge again today.”

De Rosario recorded a hat trick.

De Rosario’s diet has altered United’s planned meals. On the road, the staff ensures fish is on the menu. When players venture out, they choose a restaurant with a variety of options. Lunch at RFK Stadium after training includes a specially marked package labeled “DeRo.”

The younger players needle him about it. “I’ll tell him, ‘Hey DeRo, we’ve got some chicken here, need me to get you a plate? Okay, you’re good? No problem. I’ll eat it,’ ” said midfielder Danny Cruz, 22. “I applaud him. I don’t know how he does it. I tried it. I can’t do it.”

De Rosario acknowledges his path is not for everyone.

“I don’t recommend jumping right into it. I jumped into it, but I had support from my brothers,” he said. “I then took it to another level. . . . There are guys who are more conscious about what they eat. I’d like to think I’ve had some influence — I hope in a positive way.”