I think the first thing would be to confirm your suspicions that this is truly low blood glucose (hypoglycemia). The easiest way to screen for this is by performing home glucose monitoring with a glucose meter usually used by people with diabetes. There are several to choose from. I would advise that you get one that has a memory that can be downloaded to a computer.
I think a referral to a pediatric endocrinologist might be helpful for you. The list of causes of recurrent hypoglycemia is long, fortunately most causes are not life-threatening, and many are easily amenable to simple dietary practices and certain food avoidances (like routinely avoiding “simple” sugars as in frosted cereals, soda, juice) and consuming more complex carbohydrates (potatoes, rice, pasta) and protein. However confoundingly, some causes of hypoglycemia are precipitated by that. Ask your pediatrician for a referral.
DS
[Editor’s comment: Also, see Other causes of hypoglycemia at the Diabetes Monitor.
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