EBT is already money with strings attached - you can only spend it on food. I don't see narrowing the definition of "food" here to exclude soda to be a huge problem.
Easily sidestepped, however, there is a thriving economy in poor neighborhoods around converting EBT to cash.
Soda, I agree.
Chips ... I think you should probably allow parents to spend EBT to buy a bag of chips for a hungry/picky kid in a pinch.
Why shouldn't EBT money be allowed to purchase sugar free soda?
I don't really see the point, as a practical matter. Money being the fungible thing that it is, the only way this policy actually restricts anything is if the only money SNAP recipients ever spend on food is their SNAP benefit.
It feels much more like spite politics: We can tell these people whose morals are so bad that they need our money to survive that they cannot spend it on what we think of as junk food. That is a luxury only us hard working folk are permitted. When you are poor, you cannot suffer alone, you need to know that we are making sure you feel extra pain. Please be motivated to be better.