This is utterly crazy. If you couldn't go more than 3-4 hours between meals without experiencing dizziness, something about your diet was seriously wrong.
If you felt better after experimentally eating something different, then eating that was almost certainly healthier. Yes, even if it was donuts. Don't let cultural beliefs about food override your direct observations!
The more aware I am of my diet and how nutrition affects my body, I find the more sensitive I become to changes.
I cut coffee, bread, sugar, and beef/pork. I would eat very nutritious meals, and my energy levels and body felt amazing, but the stand up and be dizzy became more common.
Was I going through withdrawal? Is my body to accustomed to eating these foods? Should my theory be, "sugar and bread is ok as long as I eat other nutritious meals?"
I'm not sure, I'm still experimenting, and I'm utilizing the final month of my insurance with my parents to figure this out.
(If your blood pressure is on the low side raising it will likely help, but obviously consult with a doctor)