How hot? "Dr. Atkins' New Diet Revolution," the leader of the pack, has been on the New York Times paperback bestseller list for more than three years. Other titles, such as "Protein Power," "Sugar Busters!" and "The Zone," have topped the charts for weeks as well. Restaurants are catering to protein-seeking patrons; even Burger King reports that "having it your way" sometimes means a Whopper without the bun. And aside from Web sites, chat rooms and dinner party discussions, high-protein is the talk at local fitness clubs. "It's probably what you would call very trendy right now," says Rich Salke, owner of Rich Bodies Gym in Georgetown.

So how did it get to this point? After all, for the past decade, every mainstream health authority has been counseling people to eat more carbohydrates and less protein -- just the opposite of the high- protein or low-carb diets. Given this disparity, what does the scientific community think of these protein-padded regimes? And most important: Since nearly any diet that restricts consumption of some food will result in weight loss, do the protein plans keep the pounds off?

While sedentary lifestyles, restaurant-portion sizes and the ubiquitousness of food in America are all partly to blame, there's also a grain of truth in the failure of low-fat dieting--at least the way many people interpreted it. "People didn't understand that cutting fat also meant cutting calories," says Tallmadge, the dietitian. "Low-fat doesn't work if you're eating half a box of Entenmann's fat-free cake or having a big scoop of low-fat frozen yogurt every day for a snack."