When you're dehydrated, your body has to steal water from your blood (which is made up of about 90% water). This results in thicker blood which is more likely to clot, leading to heart problems and hypertension (more commonly known as high blood pressure).
Efficient delivery of nutrients
If you're dehydrated, it's more difficult for nutrients to be absorbed your body. Water acts as a lubricant making sure that all the right nutrients go to all the right places, quickly and effectively.
Better cognitive performance
A well hydrated brain means more oxygen is going to the brain meaning less headaches and sharper cognitive function.
Better muscular performance
If you're dehydrated, so are your muscles. When you drink water, you're literally watering your body like you would a plant. The more water in your muscles, the better they will work.
When you're dehydrated, your body holds onto water which causes bloating and weight gain. To ensure your body doesn't have to do this, drink up!
Conquer your cravings
Cravings and hunger pangs occur mostly between meals. To help keep hunger at bay and avoid unhealthy snacking, keep a bottle of water with you and sip to quell your appetite.