Glucagon is stimulated by dietary protein. If you eat a big carbo meal for lunch, by 3 pm you are ready for a nap because excess carbohydrates have generated overproduction of insulin. As your blood sugar drops, your brain begins to tune out. Because a massive amount of carbohydrates drove insulin levels up and glucagon down, the fats stored in your body cannot be released. You crave energy and more carbohydrates.
Hypoglycemic tendency is inherited, and often comes with a family history of diabetes.
Insulin triggers an adrenalin response. Coffee, tea and colas stimulate the release of adrenalin, as does nicotine, which is often why we use products containing caffeine and nicotine. We want to keep that adrenalin flowing. Then we lose the ability to turn it off. Exercise decreases insulin.