"given that good nutrition and a lack of stress from worrying about food allows people to develop more intellectually, raising taxes to pay for food welfare will actually raise money by introducing more workforce"

there are principles you can attack (good nutrition aids brain development, less stress aids brain development), an action to attack (raising taxes), and projected results to attack (better brain development yields higher workforce participation, higher workforce participation will raise more money).

this is an argument, something to be debated. "we'd be better if less people were hungry" is a useless platitude.