Protein is important for maintaining healthy bones and tissue. However, too much protein can result in calcium excretion through the urine. This can lead to kidney stones.
It is important that you note that not all people develop kidney stones when they consume more than 2 grams of protein per kg (2.2 pounds). You don't have to eat a lot of protein to get kidney stones.
By being careful with your sodium intake, you can prevent kidney stones. Sodium regulates the water balance of the kidneys. Too much sodium can cause kidney stones.
If you have kidney stones, you can reduce your intake of protein. Protein provides about half of the daily caloric needs for most adults. If you cut back on protein, you'll likely lose weight.
If you do decide to eat more protein, don't go overboard. Aim for less than 20% of total calories from protein.