2-hydroxyglutarate (2HG) has emerged as a potent oncometabolite that inhibits enzymes involved in metabolism, chromatin modification, and cell proliferation; however, neither the D-2HG nor the L-2HG enantiomers are tumor specific. In fact, both compounds are synthesized in a diversity of cells, but the presence of 2HG in healthy tissues is commonly disregarded as a byproduct of metabolic error. This presumption is further supported by observations that the only known causes of 2HG accumulation are hypoxia and mutations in either Isocitrate Dehydrogenase or in the enzymes that degrade these compounds. We have discovered that L-2HG is more than an aberrant metabolite, as Drosophila larvae generate millimolar concentrations of L-2HG during normal development. Larval L-2HG, however, does not accumulate simply to due defects in metabolic repair pathways. Rather, we have found that this compound is the direct product of aerobic glycolysis, as most L-2HG is generated from glucose and dependent on activation of the Drosophila Estrogen-Related Receptor, which promotes L-2HG synthesis by up-regulating Lactate Dehydrogenase (Ldh) gene expression. As a result, high levels of larval LDH activity directly synthesize L-2HG for 2-oxoglutarate. Furthermore, we have found that the resulting L-2HG pool is stabilized, in part, by lactate, which inhibits L-2-hydroxyglutarate dehydrogenase (L-2HGDH) activity and controls L-2HG abundance. Finally, we demonstrate that L-2HG influences DNA methylation and position effect variegation, indicating that this compound coordinates metabolism with epigenetic modifications during fly development. In conclusion, our findings suggest that L-2HG is more than an aberrant compound produced by enzymatic infidelity, but rather acts as part of an ancient mechanism to coordinate glycolytic flux with chromatin formation.