 According to one 2009 review updated in 2018, people with chronic kidney disease who reduce protein consumption have less likelihood of progressing to end stage kidney disease.Moreover, people with this disease while using a low protein diet (0.6 g/kg/d - 0.8 g/kg/d) may develop metabolic compensations that preserve kidney function, although in some people, malnutrition may occur.Individuals with phenylketonuria (PKU) must keep their intake of phenylalanine - an essential amino acid - extremely low to prevent a mental disability and other metabolic complications.