Adding protein to your diet can help your body heal faster from illness or injury and can help you lose weight when combined with other healthy foods and a program of physical activity. A high protein diet is not necessarily safe when followed for more than three or four months. In addition, consumption of excess amounts of protein for long periods may also affect levels of calcium in your body. Check with your doctor before adopting high-protein diet.
High Protein Diets and Urinary Calcium Excretion
Research evidence is mixed, but it suggests that for some people consuming a high-protein diet can lead to the excretion of calcium in the urine. A 2003 study published in the "American Journal of Clinical Nutrition" explains that chronic consumption of large amounts of protein leads to a condition known as hypercalciuria. This condition is characterized by impaired absorption of calcium, which is then excreted. Left untreated, hypercalciuria can lead to thinning of the bones, increased risk of sudden bone fractures and osteoporosis. A 1981 study published in "Federation Proceedings" explains that this condition appears to occur when protein consumption is approximately three times the recommended amount.
High Protein and Bone Loss
All but 1 percent of all the calcium in your body is present in your teeth and bones, providing structure and repairing and replacing bone mass as necessary. The presence of another important mineral, phosphorus, appears to decrease the loss of calcium and subsequent loss of bone that can occur with a high-protein diet. A 1990 article published in "The Journal of Nutrition" explains that individuals who consume complex forms of protein that contain phosphorus experience significantly less bone loss than those who consume simple proteins. Simple protein sources include dairy and animal proteins and complex proteins are found in soy products, beans and legumes.
High Protein Diet After Menopause
Menopause refers to the decreasing and subsequent cessation of a woman's menstrual cycle. Estrogen production declines, also decreasing the use of calcium to contribute to bone tissue. A diet high in both protein and sodium has been suggested as increasing the risk of osteoporosis in postmenopausal women. A 2004 article published in the "British Journal of Nutrition" supported this theory and found that participants who consumed a diet high in protein and sodium experienced a significant increase in the excretion of calcium.
High-protein diets may be effective for short-term weight loss, but long-term consumption of excess protein can deplete your body's calcium. In addition, high-protein diets can lead to nutritional deficiencies, inadequate fiber intake and consumption of too many saturated fats. If you have a pre-existing kidney or liver impairment, avoid high-protein diets because they place additional burdens on these compromised organs. If you're healthy, the Harvard School of Public Health recommends that you consume approximately 25 percent of your total calories in the form of protein.
- "American Journal of Clinical Nutrition"; Dietary Protein, Calcium Metabolism, and Skeletal Homeostasis Revisited; J. E. Kerstetter, et al.; 2003
- "Federation Proceedings"; Protein-Induced Hypercalciuria.; H. M. Linksweiler, et al.; 1981
- "British Journal of Nutrition"; The Effect of a High-Protein, High-Sodium Diet...; Mary Harrington, et al.; 2004
- "The Journal of Nutrition"; Dietary Protein Increases Urinary Calcium; Jane E. Kerstetter, et al.; 1989
- National Institutes of Health: Calcium
- Harvard School of Public Health: Protein -- Your Nutrition Questions Answered