(I have been covering his extraordinary postpresidential career since 2005, interviewing him frequently and traveling with him across Africa, Europe and the Mideast, as well as the United States.) We were all preparing to dig into a tempting dinner sent up to the former president's suite from a very fine restaurant in the hotel. No dairy at all." He smiled and yanked on his waistband.

Sitting down next to him, I glanced at his plate and saw none of the steak, shrimp, fish or chicken on the buffet — just a tangle of green lo mein noodles and a pile of broccoli. "I've lost more than 20 pounds so far, aiming for about 30 before Chelsea's wedding. I feel great." (He achieved his ideal weight in time for his daughter's marriage to Marc Mezvinsky on July 31, 2010.) Clinton traces his decision to change back to the morning in February 2010 when he woke up looking pale and feeling tired.

His cardiologist quickly brought him into New York-Presbyterian Hospital, where he underwent emergency surgery to insert a pair of stents.

One of his veins had given out, a frequent complication following the quadruple-bypass surgery he had undergone in 2004. (When I suffered a heart attack in late November 2010, Clinton sent me all three books.) "I just decided that I was the high-risk person, and I didn't want to fool with this anymore.

While I figured our lunch menu might be bland, that would be a small price to pay for private time with a world leader who is anything but. As we enter a private room overlooking Manhattan's busy Rockefeller Center, I'm struck with a dazzling kaleidoscope of a dozen delicious dishes: including roasted cauliflower and cherry tomatoes, spiced and herbed quinoa with green onions, shredded red beets in vinaigrette, garlicky hummus with raw vegetable batons, Asian-inspired snow pea salad, an assortment of fresh roasted nuts, plates of sliced melon and strawberries, and rich, toothsome gigante beans tossed with onions in extra-virgin olive oil. At age 66, Bill Clinton still travels and works at a pace that completely exhausts staffers who are two or three decades younger.

Subscribe to the AARP Health Newsletter As it happens, the fit, trim and sharply attired Clinton, whom I've come to know well during more than two decades covering his career, is his usual gregarious, charismatic self. The luncheon banquet gives a whole new meaning to the dreaded cliché "Eat your vegetables." And this is exactly what Clinton, who is taking on America's obesity epidemic with the same passionate commitment he brought to the presidency, wants. Yet, while coping with heart disease and the usual complaints of aging, he has managed to change his diet drastically, lose more than 30 pounds and keep the weight off.

At a subsequent press conference, Clinton recalls, his doctors tried "to reassure the public that I wasn't on the verge of death, and so they said, you know, this is actually fairly normal." Soon after, he received a "blistering" email from Dean Ornish, M. "Yeah, it's normal," wrote Ornish, an old friend, "because fools like you don't eat like you should." "I just decided that I was the high-risk person, and I didn't want to fool with this anymore. So I decided to pick the diet that I thought would maximize my chances of long-term survival." Prodded into action, Clinton started by rereading Dr. And I wanted to live to be a grandfather," says Clinton.

Dean Ornish's Program for Reversing Heart Disease, which urges a strict, low-fat, plant-based regimen, along with two books that were, if possible, even more militantly vegan: Prevent and Reverse Heart Disease, by Caldwell Esselstyn, M. "So I decided to pick the diet that I thought would maximize my chances of long-term survival." As we talk, Clinton is clearly enjoying every virtuous bite, helping himself to seconds of both the quinoa and the beans.

In addition to his dietary changes, Clinton also walks two or three miles a day, outdoors whenever possible; plus, he works out with weights and uses an exercise ball for balance drills.

And, of course, he continues to play golf, always walking the course without a cart.

For Bill Clinton, breakfast is almost always an almond-milk smoothie, blended with fresh berries, nondairy protein powder and a chunk of ice.