If you provide over half of your dad's support, and he meets the other requirements that you will find listed in the following TurboTax FAQ, then you would be able to list him as a dependent on your taxes.  While benefits provided by the state to a needy person (welfare, food stamps, housing, SSI) are generally considered support provided by the state, since you have stated that it was more than half of the food costs, not the total support cost, then you can use the following link to help determine if you provided more than half of his total support: 

https://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf 

https://ttlc.intuit.com/replies/3288503