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PKU--or phenylketonuria--is a metabolic disorder in which the body cannot break down the amino acid phenylalanine 1. If phenylalanine builds up in the body because of the disorder, it can cause brain damage that leads to intellectual and developmental disabilities, according to the National Institute of Child Health and Human Development. Because phenylalanine and other amino acids are the building blocks for proteins, people with PKU must follow a strict, low-protein diet.
Fruits and Vegetables
Fruits and vegetables contain little, if any, protein, and they are safe to eat for people with PKU, according to the National Institute of Child Health and Human Development. In fact, because protein is so common in foods, fruits and vegetables are often the main components of the diet for people who have PKU.
Child Protein Deficiency
Grain products, such as those containing wheat or rice, typically contain at least some protein. People with PKU can typically eat some grains, but they must limit and divide the quantities, because eating too much at once can cause problems. People who have PKU can tolerate some phenylalanine in the diet; in fact, the body requires some protein. MayoClinic.com advises that people with PKU devise meal plans with the total amount of phenylalanine in mind 1.
- Grain products, such as those containing wheat or rice, typically contain at least some protein.
- People who have PKU can tolerate some phenylalanine in the diet; in fact, the body requires some protein.
Because a diet lacking in protein is also lacking in several essential vitamins and minerals, people who have PKU must also consume special formulas to prevent nutrient deficiencies and help keep them healthy. These formulas--used by babies, children and adults with the condition--contain vitamins, minerals and protein but are free of phenylalanine, according to the University of Maryland Medical Center.
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- MayoClinic.com: Phenylketonuria
- University of Washington Cristine M. Trahms Program for Phenylketonuria: What Is The Diet for PKU?
- Marble, M. Phenylketonuria and other metabolic diseases: clinical, genetic and newborn screening aspects. LSU Health Sciences Center.
- Burlina AP, Lachmann RH, Manara R, et al. The neurological and psychological phenotype of adult patients with early-treated phenylketonuria: A systematic review. J Inherit Metab Dis. 2019;42(2):209-219. doi:10.1002/jimd.12065
- Hood A, Antenor-dorsey, JA, Rutlin J, et al. Prolonged exposure to high and variable phenylalanine levels over the lifetime predicts brain white matter integrity in children with phenylketonuria. Mol Genet Metab. 2015;114(1):19-24. doi:10.1016/j.ymgme.2014.11.007
- Macleod EL, Ney DM. Nutritional management of phenylketonuria. Ann Nestle Eng. 2010;68(2):58-69. doi:10.1159/000312813
- University of Washington, Cristine M. Trahms Program for Phenylketonuria. What is the diet for PKU?
- Sara, GL., Alejandra, LML, Isabel, IG, Marcela, VA. Conventional phenylketonuria treatment. Journal of Inborn Errors of Metabolism and Screening. 2010;4. doi:10.1177/2326409816685733
- Southeast Regional Genetics Network. PKU nutrition management guidelines. Updated August 2016.
- Kose E, Aksoy B, Kuyum P, Tuncer N, Arslan N, Ozturk Y. The effects of breastfeeding in infants with ohenylketonuria. J Pediatr Nurs. 2018;38:27-32. doi:10.1016/j.pedn.2017.10.009
- Guo H, Zheng Y, Wang B, Li Z. A note on an improved self-healing group key distribution scheme. Sensors (Basel). 2015;15(10):25033-8. doi:10.3390/ijns5030026
- Concolino D, Mascaro I, Moricca MT, et al. Long-term treatment of phenylketonuria with a new medical food containing large neutral amino acids [published correction appears in Eur J Clin Nutr. 2017 Aug;71(8):1027]. Eur J Clin Nutr. 2017;71(1):51–55. doi:10.1038/ejcn.2016.166
- Kose E, Aksoy B, Kuyum P, Tuncer N, Arslan N, Ozturk Y. The effects of breastfeeding in infants with phenylketonuria. J Pediatr Nurs. 2018;38:27-32. doi:10.1016/j.pedn.2017.10.009
- Southeastern Genetics Network. PKU nutrition management guidelines.
- The National PKU Alliance. Returning to diet.
- University of Washington. Cristine M. Trahms Program for Phenylketonuria. What is the diet for PKU?
Anna Aronson began working as a journalist in 2000 and spent six years at suburban Chicago newspapers before pursuing freelance work. She enjoys writing about health care topics, in particular obstetrics, pediatrics and nutrition. She received a Bachelor of Arts in journalism from Eastern Illinois University and is now studying for a Master of Science in medicine degree to become a physician's assistant.