Found this explanation in the archives here:
While there is no direct link to CAH and insulin, both insulin and cortisol have an impact on blood sugar (glucose) levels. If you go too long between meals your normal source of stored glucose in the muscles and liver will become depleted and the adrenals will be stimulated to release cortisol to enable the breakdown of protein into glucose. In your case, if this occurs little or no cortisol is produced so you will experience symptoms of hypoglycemia which include fatigue. Insulin’s role is to move excess glucose from the blood into the cells to be stored in the form of fat. There is often a rebound effect when we consume something that is sugary or easily broken down into sugar. The sudden increase in blood sugar causes a large amount of insulin to be released and this causes a sharp drop in blood sugar once again bringing on hypoglycemia symptoms. The lesson from this is to keep your blood sugar levels constant by eating frequent meals containing a good balance of carbohydrate, fat and protein.