Long-term effects of a ketogenic diet on body composition and bone mineralization in GLUT-1 deficiency syndrome: A case series

Objective: The only known treatment of glucose transporter 1 deficiency syndrome (GLUT-1 DS) is a ketogenic diet (KD), which provides the brain with an alternative fuel. Studies in children with intractable epilepsy have shown that a prolonged KD can induce a progressive loss of bone mineral content associated with poor bone health status, probably as a consequence of a chronic acidic environment. The aim of this study is to determine the long-term effects of a KD on body composition and bone mineral status of patients with GLUT-1 DS, is currently unknown. Methods: In this case series, we report the changes in body composition and bone mineral status observed in three adult patients with GLUT-1 DS who have been treated with a KD for more than 5 y. Results: A long-term KD did not produce appreciable changes in weight and body composition of adults with GLUT-1 DS. Moreover, we found no evidence of potential adverse effects of a KD on bone health. In summary, this case series contributes to a small but growing body of literature that investigated the potential long-term effects of a KD on bone health. Conclusions: Our data suggest that maintaining a KD for more than 5 y does not pose any major negative effects on body composition, bone mineral content, and bone mineral density in adults with GLUT-1 DS, a finding that is at variance with previous reports focusing on children with intractable epilepsy. Further studies with larger sizes are needed to confirm and expand our findings.