Recently, high-protein, low-carbohydrate diets have become popular. Such diets recommend 30 to 50 percent of consumed calories be from protein, while the American Heart Association recommends less than 14 percent. High-protein animal protein is usually high in saturated fats, which contribute to heart disease, diabetes and stroke. Certain important vitamins, minerals and fiber may be lacking in such high-protein diets, proving such diets nutritionally unbalanced.
Proteins Defined
Protein is an essential nutrient to the human body. A total of 22 amino acids connect in different combinations to form the many different types of proteins required by the body, and eight of them must come from dietary intake. The body uses the proteins to create new and replacement body tissues such as bones, muscles and internal organs. Children require higher protein intake because they are growing new tissues at higher rates.
Dietary proteins exist in three forms--meat protein, dairy protein and vegetable protein. Some proteins are healthier than others. Fish and soy proteins actually benefit the body by assisting in lowering blood cholesterol, while red meat and dairy proteins have high saturated fat content. Diets high in the saturated fats contribute to hypertension and obesity.
High-Protein Diet
High-protein diets, resulting in quick weight loss, can be attributed to a low carbohydrate intake. Such low levels of carbohydrates leads to unbalanced body salts, and the initial weight loss is mostly water. Long-term high-protein diets are difficult to maintain due to food restrictions. Good high-protein foods include fish, skinless chicken, pork and low-fat dairy products. Also, the highly limited carbohydrates must be whole-grain and nutrient-dense. Nutritional balance is essential for the results of high-protein diets to remain healthy.
Insulin Results
High dietary protein has the potential to result in insulin resistance. Since insulin is responsible for maintaining levels of blood glucose, dietary changes in the protein-to-carbohydrate ratios influences insulin levels. The increased intake of amino acids, from protein breakdown, affects the body's glucose equilibrium and decreases insulin's sensitivity for future glucose metabolism. Also, circulating amino acids play a role in modulating liver glucose, further complicating insulin's ability to regulate glucose. In the "The American Journal of Clinical Nutrition," Thomas Wolever and co-authors associated newly diagnosed diabetes with low-fiber, high-protein dietary intake.
Kidney Results
Kidneys function to remove waste products from the body's circulatory system. The speed and efficiency of the filtration is called the glomerular filtration rate, or GFR. Increased protein intake places additional pressure on the kidneys to filter the excess proteins circulating within the blood. People with chronic kidney disease or mild renal insufficiency who are eating high-protein diets will likely increase their GFR, which is can lead to further complications.
Coronary Results
Although the amounts and the types of protein intakes differ in various studies, a positive correlation has been shown between the amount of meat protein or dairy protein and coronary heart disease. Higher protein intake is associated with higher saturated fats. Saturated fats increase blood cholesterol levels, a major risk factor in heart disease. Fats, cholesterol and calcium build up in arteries, causing blockages that lead to disease, stroke and heart attack. A high-protein diet has detrimental results on the coronary system.
References
- The American Journal of Clinical Nutrition: Low Dietary Fiber and High Protein Intakes Associated with Newly Diagnosed Diabetes in a Remote Aboriginal Community
- The Annals of Internal Medicine: The Impact of Protein Intake on Renal Function Decline in Women with Normal Renal Function or Mild Renal Insufficiency
- Annual Reviews of Nutrition: Role of Dietary Proteins and Amino Acids in the Pathogenesis of Insulin Resistance
- Feminist Women's Health Center: High Protein Diets--Are You Losing More Than Weight?
- American Journal of Epidemiology: Associations of Dietary Protein with Disease and Mortality in a Prospective Study of Postmenopausal Women
Member Comments