Eating can cause low blood pressure.  Postprandial hypotension can show up as dizziness or falling after a meal.
D001342:Autonomic Nervous System Diseases; D001794:Blood Pressure; D004244:Dizziness / Q000209:etiology*; D004435:Eating; D006801:Humans; D007022:Hypotension / Q000150:complications*; D019518:Postprandial Period; D012307:Risk Factors