FORT MYERS, Fla. -- David Ortiz, who says he has dropped 20 pounds in the past two months and looks like it, is on a diet unlike any that most of you know.

For starters, he can't eat chicken, an enormous sacrifice for a guy who had pollo many nights growing up in his native Dominican Republic.

David Ortiz is as big as ever with Sox fans. Jim Davis/Getty Images

He can't eat egg whites, just the yolks.

No shrimp, but lobster, yes.

Some salmon, but no grouper.

Alcohol, no.

"I was in many resorts this winter, and all I did was watch people drink," he said. "I have a friend here who is the general manager of El Presidente [a popular Dominican beer]. He called me yesterday, and said, 'David, how much do you want me to send over?' I had to tell him, 'Never mind.'"

No bread. No sweets.

Beef, yes, and without restrictions. No one telling him he can't eat a steak bigger than a deck of cards.

And, of course, lots of salads and vegetables.

Ortiz, who says his weight is down to around 250 pounds, carries a business card-sized list of foods he cannot eat on his diet, which he started, he said, for reasons that had nothing to do with baseball. His cholesterol had risen to dangerously high levels. "Over 300," he said.

His agent, Fern Cuza, suggested he try it. Cuza carries around a similar list, though he admits to being not as devoted to sticking to it as Ortiz. "I take weekends off," the agent said.

Ortiz said the results have been almost immediately noticeable.

"I feel great," he said. "I can feel the difference when I swing the bat, and when I work out, I don't get as tired."

The beauty of his diet, he said, is that it is all natural, involving no supplements. The parameters were determined in a clinic in the Dominican Republic, where he underwent something called bioelectrical impedance, which is a procedure that its proponents say can assess body composition, measuring body fat, lean muscle mass and intra- and extracellular fluids.

This was followed by what its inventors call the ALCAT test, an acronym for something called antigen leukocyte cellular antibody test. It is a blood test said to measure the body's response to various food and chemical substances at the cellular level. It claims to be able to tell what food "intolerances" or "sensitivities" an individual's body has, and from the results, a personal diet can be drawn. Ortiz's diet, for example, is not the same as Cuza's. It all depends on which foods are deemed intolerant for one's body.