Ghrelin is highest when a person is fasting and lowest after a meal. Research shows that people with PKU
have lower ghrelin after consuming Glytactin than after having an amino-acid based formula. Lower
ghrelin
means less worry about being hungry on the Phe-restricted diet.
Macleod E et al. Mol Genet Metab. 2010 Aug; 100(4): 303–308.