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.
Weight loss on a high carbohydrate diet is mostly water and muscle loss. Any subsequent weight gain is fat gain. The more carbohydrates you eat, the earlier adrenalin is produced as the blood sugar goes down. Blood sugar swings are more extreme and faster the more carbohydrates you eat. The ideal ratio of protein to carbohydrates is 3 to 4.