Low-carb, high protein diets stress kidneys and may weaken bones

August 20, 2002 in Weight Management

Low-carb, high protein diets stress kidneys and may weaken bones

Diets that are heavy on protein and low on carbohydrates can increase the risk of kidney stones and reduce the body's ability to absorb calcium after just 6 weeks, say researchers from the University of Chicago. Their findings come at a time when an increasing number of North Americans, looking for fast weight loss, are turning to low-carbohydrate, high-protein (LCHP) diets.

But while LCHP diets have been shown to help lose weight in the short term, these diets are less successful over the long run and may even be hazardous to health. Some protein-rich foods can be high in fat, which increases the risk of heart disease and type 2 diabetes. And a lack of carbohydrate-rich foods such as fruits and vegetables can deprive the body of vitamins and minerals, while insufficient glucose from carbohydrates, the body's preferred fuel source, can lead to fatigue, dizziness and difficulty exercising.

And according to this new small study (10 healthy adults), 6 weeks on an LCHP diet increased the acid load to the kidneys, raising the risk of kidney stones. Animal protein has been shown to boost urinary excretion of oxalate, a compound that combines with calcium and other compounds to form kidney stones.

At the same time, adults in the study had higher levels of calcium in their urine, suggesting a decreased absorption of the bone-building mineral and an increased risk of osteoporosis.

While it is not clear from the study whether bone mass was affected, the findings indicate that such diets may increase the risk of bone loss over the long term.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.