Vegetarians by and large have lower creatine levels than meat-eaters. A study by Walker showed that the average sedentary person uses up about two grams of creatine per day. This creatine is broken down into a waste product called creatinine, which is collected by the kidneys and excreted in the urine. Athletes use up much more than two grams per day, with the exact amount depending on the type of sport, intensity level and muscle mass. The average person consumes about one gram of creatine per day.
Creatine is found in moderate amounts in most meats and fish, which are, after all, skeletal muscle.
Good sources of dietary creatine include tuna, cod, salmon, herring, beef and pork. Tiny amounts are found in milk and even cranberries. While it would seem logical that chicken and turkey have creatine as well, we were unable to find any published data to confirm this. Cooking destroys part of the creatine that exists in these foods. An important thing to remember is that meats and fish contain a lot more than creatine.