What is the primary dietary requirement for individuals with phenylketonuria (PKU)?

• A. High-fat diet
• B. Phenylalanine-free diet
• C. Low-sugar diet
• D. Protein-rich diet

Answer: (B)

Individuals with phenylketonuria (PKU) have a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for the conversion of phenylalanine to tyrosine. When phenylalanine accumulates in the body, it can lead to serious neurological damage and developmental issues. Therefore, the primary dietary requirement for individuals with PKU is a phenylalanine-free diet. This means they must avoid foods that contain high levels of phenylalanine, which is found in protein sources such as meat, dairy, eggs, nuts, and certain grains. Instead, they rely on specially formulated medical foods and low-protein alternatives to meet their nutritional needs without introducing harmful levels of phenylalanine into their system. This dietary approach is essential for managing the condition and preventing intellectual disability and other complications associated with PKU.