All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
If the ones giving this food or water do not specify the poor in particular in giving it, then there is no harm on you in taking it and you bear no sin for it. Also, there is no harm on you in taking the water that is offered to you even if you are not thirsty. When you take the water, it becomes your property and you are entitled to give it to whomever you wish or keep it for some other time when you need it. The same goes for the food that is offered to the fasting people; if those giving it do not stipulate that it must be offered exclusively to the fasting people and may not be offered to anyone, then there is no harm on you in taking it. However, if the ones giving it specify the fasting people with it, then their wish must be honored and it is impermissible for you to take that food. If you take it, then you should give it to a fasting person who deserves it. The same applies to the food that is allocated to the poor; it is impermissible to take it if you are not considered poor.
Allah knows best.