Until now, β-hydroxybutyrate (BHB) has been known as a compound produced by the liver to be used as fuel. In a new study, researchers discovered that BHB also participates in another metabolic pathway; in this case, an enzyme called CNDP2 joins BHB to amino acids; furthermore, the most abundant BHB-amino acid, N-β-hydroxybutyryl phenylalanine (BHB-Phe), can influence body weight and metabolism in animal models. β-Hydroxybutyrate (BHB) is an abundant...