First, it was water. This is a consistent and refreshing beverage which can cover all the needs of our body when it comes to recovering the fluids it loses. People thought that water would be the only beverage and this happened for millions of years. However, once agriculture and growing animals developed, milk appeared, then beer, wine, coffee and tea, the newest beverages being the energy drinks and the refreshments.
If you are wondering about what you should choose from sugar free beverages and sweet ones, you should know that the answer in somewhere in the middle. You shouldn't drink too many sweet beverages, but you shouldn't always go for diet drinks either. It is quite difficult to choose the best drink since there are so many options. A few researchers at Harvard studied all the beverages in the world and divided them into six categories, according to the number of calories they have. Apparently, water is the best drink you can go for, but this doesn't mean that it is the healthiest one, too.
It is quite impossible to figure out how much water one needs to drink throughout the day. The quantity of water to be drunk depends on how much you eat, on the weather outside and on how active or passive you are. Therefore, they estimated that men should drink about fifteen glasses a day, while women should drink about eleven glasses. As for the nutrition advice everyone gets, which is that you should drink eight glasses of water a day, there is nothing to prove it, but it covers part of your water needs.