What is it? Ground beef comes from the tougher and less popular cuts of beef, and the trimmings left over when sides of beef are carved into steaks and roasts. Grinding tenderizes the meat. You can also ask your butcher to grind meat from a particular cut of beef, such as a chuck roast or even sirloin.

What's the difference between "ground beef" and "hamburger?" According to U.S. Department of Agriculture guidelines, extra beef fat may be added to "hamburger" but not "ground beef," if the meat is ground and packaged at a USDA-inspected plant. A maximum of 30 percent fat by weight is allowed in either hamburger or ground beef. Both can have added seasonings but no water, phosphates, extenders or binders.

Why do you have to cook ground beef thoroughly, when you can have steaks and roasts that are cooked rare? In a whole cut of beef from a healthy animal, the interior of the meat is essentially sterile, even before cooking. Any bacterial contamination is on the outer surface of the meat, and that is killed when the meat is cooked.

"But if you take that cut of meat and put it through a grinder, that bacteria on the outer surface has now gone throughout the meat, because you've mixed it all up," said Jacob Schmidt, the Utah Beef Council's dietitian. "So the center of a ground beef patty isn't like the center of a steak. It needs to be cooked to medium, or 160 degrees."

How should ground beef be stored and handled? Refrigerated ground beef should be used within two days. Thaw frozen ground beef in the refrigerator (not on a kitchen counter or at room temperature). When cooking ground beef, avoid cross-contaminating other foods by washing your hands with soap and hot water before and after handling the meat, and washing all utensils and surfaces that came into contact with the meat.

How much beef should I buy? Because there's some shrinkage during cooking, one pound of fresh ground beef provides four 3-ounce cooked servings.

What kind of nutrients does ground beef supply? A 3-ounce serving (about the size of a deck of cards) provides more than half the protein, 14 percent of the iron and 38 percent of the zinc most people need each day. It's also a significant source of:

B-12, B-6, niacin and riboßavin.

An 85 percent lean, pan-broiled patty has 197 calories, 11 grams of fat and 73 milligrams cholesterol. If the patty is 90 percent lean, it has 173 calories, 9.1 grams of fat and 70 milligrams of cholesterol. By comparison, a 3-ounce portion of 70 percent lean ground beef "crumbles," pan-browned, has 230 calories, 15 grams of fat and 75 milligrams of cholesterol.

How can you cut the fat? Here's a method from the National Cattlemen's Beef Association: Brown the beef in a skillet over medium heat until it's fully cooked. Using a slotted spoon, remove beef crumbles onto a plate lined with three paper towels. Let sit one minute and blot the top of the beef with more paper towels. Place the beef in a colander over a large bowl. Pour very hot water (not boiling) over beef to rinse the fat. Drain five minutes. This removes up to half the fat in 70 percent to 85 percent lean ground beef.

SOURCES: U.S. Department of Agriculture and the National Cattlemen's Beef Association