That ongoing migraine that haunts you day and night may be one of the symptoms of not eating enough calories. Going through a long time without eating, eating high-sugar foods, and putting yourself under a strict diet regime can all cause hypoglycemic headaches or migraines.

Can eating too little give you a headache?

Can Hunger Cause Headaches? When you haven't had enough to eat, you may not only hear your stomach rumble, but also feel a strong headache coming on. A hunger headache occurs when your blood sugar starts to dip lower than usual. Being hungry can also trigger migraine headaches for some people.

What are the side effects of not eating enough?