I think the more prevalent in the food we eat is Carbon-12 which is present in Most of the food we ingest. Both carbon-12 and carbon-14 are isotopes of carbon, they differ in the number of neutrons in each atom. Because of the different number of neutrons, carbon-12 and carbon-14 differ with respect to radioactivity. Carbon-12 is a stable isotope but carbon-14 undergoes radioactive decay.