Remember tea, coffee and aerated drinks dehydrate the system if had in excess. We have always advocated that eat everything in moderation. Sugar and caffeine are both sources of controversy. One can of cola contains about eight teaspoons of sugar. One faction of the sugar controversy states that it can cause cavities and is a source of empty calories, i.e. calories with no other nutrients such as vitamins and minerals. The problem with empty calories is that it keeps you from eating other foods that are more nutritious and beneficial to your health. The other faction says that sugar is an evil that has detrimental physical and mental effects and it needs to be avoided at all costs. Since sugar is a carbohydrate, it can be used by the body for energy, or if consumed in excess, it can be converted to fat.
In terms of quitting soda, it usually takes lots of motivation. However, some people say that after an initial period of adjustment i.e. headaches, lethargy, feeling low etc., they do feel physically and mentally better, which is enough to keep them from going back. Always keep alternative beverages handy, because if you are thirsty and there is nothing else around, it becomes too easy to go back to the good old fizzy friend!