Disclosed is the use of beta-hydroxy-beta-methylbutyric acid (HBM) in the manufacture of a medicament for improving glucose tolerance and insulin resistance in a prediabetic individual or other potential prediabetics to prevent or delay the development of diabetes. In certain embodiments, the beta-hydroxy-beta-methylbutyric acid is administered via a nutritional composition. HBM is also known as beta-hydroxy beta-methylbutyrate, 3-hydroxy-3-methylbutanoic acid, beta-Hydroxyisovaleric acid, or 3-Hydroxyisovaleric acid.
