From ediets.com

Health and Diet
According to the American Dietetic Association, you can reduce the fat content of cooked ground beef by as much as 50 percent if you rinse the beef after cooking! You still retain the nutrients such as iron, zinc, and B vitamins, so enjoy this healthier version. So before you serve up that burger, take the time to rinse off the extra fat. A small step will go a long away.

Fitness
It is estimated that for every one pound increase in lean muscle mass, resting metabolism increases 30 – 50 calories per day. If you can add 5 pounds of lean mass you could burn off 20 – 25 pounds in a year without changing your diet.