Diet-induced headaches

If you’re searching for the cause of that niggling headache, it’s possible that what you’re eating – or drinking – could be to blame.
Stop over-restricting your kilojoule intake

Spacing your meals too far apart or eating at irregular intervals causes a dip in blood-glucose levels, which drives your body into starvation mode. This triggers a cascade of hormones and brain chemicals similar to your body’s response to stress, which can bring on headaches. Once you fuel up, the headache should go away.
Tip
You should wait no more than four hours between meals. Try light snacks between meals, such as a handful of almonds.
Stay hydrated

Dehydration is a common headache trigger. Experts suspect it may have to do with narrowing of blood vessels in the brain, which reduces the brain’s supply of blood and oxygen. Not getting sufficient electrolytes may also contribute to headaches.
Tip
By the time you feel thirsty, your body is already a little dehydrated, so rehydrate often. Have a glass of water with every meal and between meals.
On the other hand, these are the signs you’re drinking too much water.