Near the top of the U.S. Department of Agriculture (USDA) Food Pyramid, you'll find meats and dairy. These are the protein groups. They're at the top, because you don't need very much of them in a given day.
For meats, nuts, fish, beans--the USDA recommends a minimum of two servings a day. A serving of meat is about 2-3 ounces, which is approximately the size of your palm. Same size serving for dairy products--milk, yogurt, cheeses--which is 1.5 ounces of natural cheese, or 2 ozs. (2 slices) of processed cheese.
A lot of us eat way too much protein. We just don’t need so much; but we do need a little for muscles, organs and brain functions. There's lots of fat in protein too, the unhealthy saturated kind.