Hi Everyone!!
The reason why they want you to avoid caffeine is due to its dehydrating potenial. During the first month of so post op you are already at high risk of dehydration. For example, for every 8 oz glass of a caffeinated beverage you would have to compensate with 16 oz to adequatley rehydrate your body. If the body is already dehydrated you could put your body at risk. Also, to be the most metabolically active you need to be hydrated. There is no quicker way to stop loosing weight then to become dehydrated. Soooo, that is the risk. Hope this helps.
Hugs!!