A high protein diet increases the risk of dehydration, may place increased strain on the kidneys and liver and does not improve muscle bulk, according to the Victorian Government’s Better Health Channel.
While high protein, low carb diets have long been marketed as excellent for promoting weight loss, the increased protein may place strain on the kidneys and lead to permanent renal damage.
This damage may occur from the increased ammonia levels, a dangerous byproduct of protein metabolism that is converted to urea and then collected by the kidneys and then removed from the body in urine.
“The more protein we eat each day, in excess of our needs, the more work our kidneys must do to get rid of the
ammonia,” according to the Better Health Channel.
This is reflected in a study by the University of Connecticut that found the more protein you eat, the more water you should drink.
The study analysed five athletes who consumed low, moderate and high levels of protein for four weeks at a time, with their hydration status evaluated bi-weekly.
They discovered that when the athletes consumed high levels of protein, their blood urea reached unusually high levels, which returned to normal when protein intake was reduced.
We found that certain hydration indices tended to be influenced as the amount of protein in their diets increased,” says Rodriguez, one of the study’s authors.
Other tests indicated that the high protein diet caused the kidneys to produce more concentrated urine.
“Based on our findings, we believe that it is important for athletes and non-athletes alike to increase fluid intake when consuming a high protein diet, whether they feel thirsty or not, because our study subjects said they did not feel a difference in thirst from one diet to the next,” says Rodriguez.
In the study, a high protein diet was classified as four times the American recommended daily allowance, which is 70 grams of protein for a person weighing 68kg.
In Australia the Government’s Better Health Channel recommends that protein levels are consumed at 0.75g/kg of body weight for adult women, 0.84g/kg for adult men and 1g/kg for men and women over 70. Protein deficiencies in Australia are very rare.
The advice goes on to say that vigorous exercise does not require increased protein consumption.
“This belief is false. It is the stimulation of muscle tissue through exercise, not extra dietary protein, which leads to muscle growth.”
“Studies show that weight-trainers who do not eat extra protein (either in food or protein powders) still gain muscle at the same rate as weight-trainers who supplement their diets with protein,” the article says, adding that a very high-protein diet can strain the kidneys and liver, and prompt excessive loss of the mineral calcium.
However the Better Health Channel does recommend that protein is consumed after exercising – whether cardio or weight training – to improve muscle recovery and growth.
For more information on hydration, check out THORZT’s Information Centre.