what kind of food are you eating? it sounds like you might be eating something you're allergic to. Either that or you're metabolism is messed up and your blood sugar is doing weird things by running out of energy buy late afternoon.
Hi,
Are there other symptoms present? Some food can trigger headaches. It would help to have a headache journal to identify which possible food triggers your headache. You may also benefit from the headache tracker here in Medhelp. If it persists, it is best that you have this checked by your doctor for proper evaluation. Ice pack and medications may provide relief from the pain. Take care and do keep us posted.