Eating a meal before you start drinking particularly fat is efficient at preventing absorption of alcohol. Hence taking a teaspoon of olive oil before drinking prevents hangover effects. Hangover causes dehydration by increasing peeing, because of this potassium and other salts may lost from the body. Bananas and kiwi fruit can both restore potassium to your body which has been lost to alcohol's diuretic effect. Eggs contain cysteine, which could help the liver to breakdown the toxin acetaldehyde, a byproduct from what alcohol does to your system.