There seems to be no end to the attacks on our beloved backyard grill. First experts tell us that those delicious, juicy steaks are a top contributor to heart disease. Next they say a rare burger could harbor deadly E. coli bacteria. Then, this spring, the U.S. confirmed a third case of domestic mad cow, this time in Alabama.

But don't put away your tongs yet. You can still enjoy a safe steak -- especially if it's from grass-fed beef. Mounting research shows that cows fed a natural diet of grass produce beef with less overall fat, less saturated fat, and fewer calories: A six-ounce grass-fed steak can have 100 fewer calories than one from a grain-fed animal. If you eat an average quantity of beef (66.5 pounds a year, guys), switching to grass-fed will save you 17,733 calories annually. Without making any other changes to your diet, you could shed five pounds. No willpower required.

The Union of Concerned Scientists (UCS) confirmed the comparative health benefits of grass-fed beef this March. In the most comprehensive study to date, it asserted that in addition to being lower in saturated fat and calories, grass-fed beef contains more omega-3 fatty acids than meat from grain-fed animals. (Omega-3s are the "good fats" commonly found in fish. They help reduce the risk of high blood pressure and heart disease as well as depression and possibly even Alzheimer's.) Sixty percent of the fatty acids in grass are omega-3s. Meanwhile, studies provided by grass-fed beef advocates show that the longer cows spend eating grass, the more omega-3s remain in the meat.

Grass-fed beef is also higher in other potentially good fats called conjugated linoleic acids, or CLAs. Early studies suggest that CLAs could be miracle agents that do everything from encouraging weight loss to preventing cancer. And though CLAs are found in all meat, grass-fed cows have three times as many as grain-fed.

But how does grass-fed beef taste? To this day, all "prime" beef -- the ultimate steakhouse decadence -- is finished on grain to ensure that the meat is properly marbled with fat. And if juiciness is your primary concern, grain-fed's the way to go. "Both types of beef are rich in what beef's good at delivering: protein, zinc, iron, and B vitamins," says Mary K. Young, nutrition director of the National Cattlemen's Beef Association. "Flavor and tenderness are a matter of personal preference."

For many years even advocates admitted that grass-fed meat was leaner, and, therefore, less immediately appealing than its fattier counterpart. But as grass-fed ranchers learn more about which breeds do well on grass -- old English breeds such as Black Angus, Red Angus, and Hereford, all raised on grass for thousands of years -- the tenderness and flavor is improving.

That's what Sarah Stegner, the chef-owner of Prairie Grass Café in Chicago, learned last fall when Tallgrass Beef Company, a boutique Kansas ranch, sent samples. Part of Chicago's Green City Market, which sells only products from sustainable farms, Stegner is the first to admit that she goes out of her way to use naturally raised food. But, she says, "in the end, it's about what tastes good. And I was blown away by the flavor."

Finding lean beef requires knowing your terms. "A lot of people seek out the 'organic' label, but that only means that cows are fed organic grain," says Jo Robinson, creator of eatwild.com, a grass-fed info site, and author of Pasture Perfect. "The healthiest beef is 100 percent grass-fed."

Sadly, you're unlikely to find grass-fed beef at your local grocer. The majority of grass-fed suppliers are small ranchers (see below) who sell to gourmet stores and big families. Case in point: Maple K Farms in Colfax, Washington, sells only sides and quarters -- a minimum of 100 pounds. Sound crazy? The farm has a multiyear waiting list.