This patient support community is for questions related to juvenile diabetes including
Celiac disease,
depression, diabetic complications, hyperglycemia /
diabetic keto-acidosis,
hypoglycemia, islet cell transplantation,
nutrition, parenting a diabetic child, pregnancy, pump therapy, school issues, and teens with
diabetes.
I'm not quite convinced that it's diabetes that is causing your dizziness, especially since you say it was ruled out a year ago, but to be on the safe side have your doctor check your glucose again. If it turns out ok then talk to your doctor about any other possible causes. It may be worthwile to consider seeing an ENT doctor as it could be an ear problem (like a middle ear infection), a neurologist, or even a GI (gastrointestinal) doctor, since it seems to be happening after eating -maybe it's a digestion issue. I know I sometimes feel dizzy when I'm nauseous after eating. And as CG mentioned above, high sugars do make you feel light headed (as do low sugars -anything out of normal range), but since you don't mention any other symptoms associated with diabetes it seems there's something else causing your dizziness.
Let us know of the outcome and feel better!