Can our body be over hydrated?
Yes. People have actually died from over hydration.
It is possible to over hydrate your body. This happens when one is drinking more fluids than the solid food which has small amount of sodium. To solve this, you need to add your solid food portion with some salt. Read more on http://www.livestrong.com/article/487287-how-to-tell-if-you-are-overhydrated/.