Hi there - I can't give you any medical advice but a bit of common sense might be in order. It does seem to me that one meal a day for a 19 year old young man is simply NOT enough. Your stomach might be giving you griping pains because it's desperate for something in it!  Also, wind can cause pain too & that might be because your stomach/bowels are just full of gas. You MUST eat 3 meals a day & drink plenty of fluids. If you do & the symptoms continue after a few days then make an appt. with your GP. I honestly don't think you've got anything serious to worry about. :)