Reactive Hypoglycemia: This condition is characterized by a drop in blood glucose levels after consuming high-sugar foods, leading to symptoms such as drowsiness, shakiness, and hunger. Despite normal A1C and insulin levels, individuals can still experience reactive hypoglycemia due to an exaggerated insulin response to sugary foods.

Dysglycemia: Fluctuations in blood glucose levels can cause symptoms like fatigue and sleepiness after eating, even if A1C and insulin levels are within normal ranges during testing.
Gastrointestinal Motility Disorders: Conditions such as gastroparesis can lead to rapid gastric emptying, causing a spike in blood glucose followed by a crash, resulting in postprandial somnolence.
Sleep Disorders: Underlying sleep disorders like sleep apnea or narcolepsy can be exacerbated by the consumption of sugary foods, leading to increased drowsiness.

Insulinoma: A rare tumor of the pancreas that produces excess insulin, leading to hypoglycemia. Although A1C and insulin levels may be normal during testing, an insulinoma can cause episodic hypoglycemia.
Adrenal Insufficiency: A condition where the adrenal glands do not produce enough cortisol, which can lead to hypoglycemia and increased drowsiness after eating.
Pituitary Tumors: Certain pituitary tumors can affect hormone regulation, including insulin and cortisol, leading to hypoglycemia and postprandial somnolence.

Glucose Transporter Type 1 Deficiency Syndrome: A rare genetic disorder that affects glucose transport in the brain, leading to symptoms like seizures, developmental delay, and episodic hypoglycemia.
Fructose Malabsorption: A condition where the body is unable to absorb fructose, a common sugar found in many foods, leading to gastrointestinal symptoms and potentially postprandial somnolence.
Galactosemia: A rare genetic disorder that affects the body's ability to metabolize galactose, a sugar found in milk and other dairy products, leading to symptoms like hypoglycemia and lethargy.