Nearly a year ago, Cathy Kapica, a director of nutrition education at Quaker Oats, got an offer to be McDonald's first "global nutrition director." "I was skeptical," she says. And for good reason: in a nation plagued by obesity, McDonald's is viewed as public enemy No. 1. But the more Kapica considered the job, the more she saw the good she could do, since McDonald's serves 47 million meals a day. "What better way to effect change?" she says. And so Kapica signed on last fall. In-house nutritionists are now a vital part of food companies' efforts to respond to increasing pressure from health officials. Critics, like Michael Jacobsen of the Center for Science in the Public Interest, deride these dietitians as "PR agents for indefensible products." Nonetheless, fast-food companies do appear to be thinking healthier: before Kapica's arrival, McDonald's already planned to phase out supersize items and add entree salads and lower-fat McNuggets. Kapica is helping to develop a line of low-fat salad dressings, and she's devised tips for reducing the bad stuff in a McMeal. At lunch, she says, order a Quarter Pounder without cheese and a Fruit 'n Yogurt Parfait instead of a hot fudge sundae, and use half a pack of Caesar dressing on your side salad. That cuts the fat content by more than a third of the suggested daily intake. Kapica wants more fruits and veggies on the menu, but critics dismiss such moves: low-fat fare will disappear when the media find a new crisis, they charge. That will depend on how much power Kapica gets. It does look a little strange, after all, that the top nutritionist reports to the head of McDonald's charity arm.