Amino acids provide the building blocks for protein, and creatine is one such amino acid. It's found in meat, fish and endogenously in the human body. Your body converts creatine to creatine phosphate or phosphocreatine and stores it in muscle tissues, where it serves as a fuel. Because of creatine's role in energy, athletes and bodybuilders commonly take creatine supplements, according to the University of Maryland Medical Center. Studies showing that creatine improves athletic performance have yielded conflicting results, however, according to the medical center.
The Human Body
Your very own body is a natural source of creatine, since the amino acid is found naturally in vertebrates. The human body can manufacture creatine, using the amino acids arginine, glycine, and methionine, according to New York University Langone Medical Center. The average-sized adult male stores roughly 120 grams of this protein, according to Melvin Williams, author of "Creatine: The Power Supplement." You may have more or less than this amount, depending on your size.
Wild game is the richest dietary source of creatine, according to the University of Maryland Medical Center. Game meats include rabbit, venison, elk, wild boar, ostrich, moose, buffalo, bison, squab and wild duck. As a bonus, game meat has significantly fewer calories, more lean body tissue and less saturated fat than domestic meats, according to the South Dakota Department of Health. Game meat is also higher in heart-healthy polyunsaturated fat than domestic meat.
Creatine is found in domestic meat. If you're interested in choosing meats that have the greatest amount of creatine, however, free-range meats are likely to offer a richer source of creatine than traditional, commercially produced meats. Lean meat options include chicken breast, turkey breast, Cornish hen, lamb chops and veal loin. If you choose pork, opt for lean cuts such as the center loin and the tenderloin.
Fish provides another natural source of creatine. On average, a 3-ounce cooked serving of fish contains 1 to 2 grams of creatine. As with meat, the amount may be more or less, depending on the quality. Farm-raised fish fed a poor-quality diet may contain lower levels of creatine than wild fish and wild-caught fish. In addition, fish is naturally lean, low in calories and rich in beneficial fats.