Food you consume while working is considered by the ATO to be private in nature and not to be in connection with your enterprise. You can only claim a GST credit if the purchase relates to your enterprise. Therefore, you cannot claim the cost of lunches in your BAS.
Water is GST-free. This means if you bought water to either sell or give away (e.g. to your passengers in the ride-sharing economy), the price you paid didn’t include GST. Thus, no GST credit can be claimed when submitting a BAS.