About 1 pint (480 mL) of blood is taken when you donate. It takes about 10 minutes. The whole process-including answering questions and having a short exam-takes up to an hour. Donated blood is tested to make sure that it is safe to use.
Soda is an unhealthy beverage because it's high in calories and sugar but low in vitamins and minerals. Coca-Cola is one example of a type of soda that's sugary and packed with calories, but Coke Zero is one alternative that is sugar-free.
In brief: In moderation. Coke zero is a diet coke product that uses aspartame as an artificial sweetner. In moderation, it is not harmful. I recommended no more than two per day to my patients. Consult with your doctor to see if you have other conditions that would not be conducive to taking coke zero. In brief: In moderation.