The invention provides methods for, and compositions effective for, treating obesity, inhibiting weight gain, treating diabetes mellitus, inhibiting atherosclerosis and treating related disorders and conditions comprising administering a pharmaceutically effective amount of at least one compound capable of inhibiting AC5 to a patient. The compound capable of inhibiting AC5 may be administered singly or in combination with another agent. In some embodiments, the AC5 inhibiting compound is 9-β-D-arabinofuranosyladenine (AraAde). The compounds may be administered in an amount of about 1 to about 200 mg/kg/day, about 1 to about 100 mg/kg/day, about 10 to about 80 mg/kg/day, about 12 to about 40 mg/kg/day or about 15 to about 25 mg/kg/day. In some embodiments, the compound is administered orally.
