What would be a good diet for someone who has hypoglycemia symptoms off and on?

Low carb. The most effective diet is a restricted carbohydrate six meal regimen. This should be set up by a registered dietician.
4 reactive hypoglyce. Eat only meat or fish or cheese or eggs or poultry and low starch veggies, drink only water. In other words avoid all carbs, carbs will only briefly raise your sugar levels and then your Insulin levels. The fats in the meat or fish or cheese or eggs or poultry will act like a "log on your metabolic fire" to keep your blood sugar stable for hours without raising insulin.