Despite the fact that short-term high protein (HP) diet could be necessary in several pathological conditions (e.g., malnutrition, sarcopenia, etc.), and physiological conditions (i.e., endurance training for athletes), it is evident that “too much of a good thing” in diet could be useless or even harmful for healthy individuals.
Many adults or even adolescents (especially athletes or body builders) self-prescribe protein supplements and overlook the risks of using them, mainly due to misguided beliefs in their performance-enhancing abilities.
Extra protein is not used efficiently by the body and may impose a metabolic burden on the bones, kidneys, and liver. Moreover, HP meat diets may also be associated with increased risk for cardiovascular disease and cancers due to intakes of saturated fat, cholesterol and other associated dietary factors such as nitrate content.
Guidelines for diet intake should adhere closely to what has been clinically proved, and by this standard there is currently no basis to recommend high protein/high meat intake above.
Current guidelines state that consumption from 0.8 to 1.2 grams per kilogram body weigh per day of proteins is sufficient to meet the nutritional needs of virtually the entire population, although people in the Middle East typically consume much higher amounts (1.2-1.6 g/kg/d), which comprises about 15-20 per cent of total caloric intake.
A common principle underlying most popular HP diets is that the source, rather than quantity, of energy is most relevant to weight loss, hence, Atkins’ recommendation to “count carbs not calories.”
Under this model, excess carbohydrate consumption leads to increased insulin secretion, which promotes adipose tissue storage and, ultimately, weight gain.
Although variations exist between popular HP diet prescriptions, all subscribe to the principle that carbohydrates generally should be avoided, which, by definition, requires increased consumption of foods high in protein and fat.
As such, popular HP diets can be expected to bring about significant changes in kidney functions that may lead to disease such as kidney stones and/or a loss in kidney function.
The effect of popular HP diets on fluid, electrolyte and acid-base status in individuals with chronic kidney disease has not been carefully examined. Nevertheless, the obvious theoretical risks in this population include serious electrolyte derangements, volume depletion, and metabolic acidosis.
Despite the controversy surrounding a HP diet and bone health, higher protein intake seems to be beneficial for bone mineralisation and maintenance in a healthy population because it increases growth hormone levels.