During the day, a few hours without eating causes your blood sugar to drop. This can leave you feeling tired and without energy to continue through the day. The nutrients and energy you get from food fills your internal tank to allow you to complete your daily tasks. To help keep your tank filled throughout the day, be sure to start out eating breakfast within an hour of waking in the morning, since this is when your blood sugar is lowest. Then, refuel with a small meal or snack every few hours throughout the day to keep you feeling sustained. In your meals and snacks, focus on eating whole grains and foods high in fiber to keep you fuller longer and to avoid spikes and drops in blood sugar during the day.