Hi Annabo,   When you consume protein, the protein is digested and broken down into amino acids. When you consume excess protein, nitrogen is removed from the extra amino acids and the amino acids are converted and stored as fat.  The remaining nitrogen is processed by the liver and eventually excreted by the kidneys.  The extra nitrogen load can cause kidney damage.  Additional concerns with high protein diets are the increased potential for developing kidney stones, osteoporosis (promotes calcium loss), and high blood fats (high protein sources are often high in fat and cholesterol).   If you are healthy without liver/kidney disorders, following a high protein diet for a short period of time is not likely to be harmful, but select your protein sources wisely.   All the best, Lisa Nelson RD Be Heart Healthy and Lose Weight