Of course, it drags in the ususal, "Who is government to tell us what to eat?" comments, but since it is the government doling out the funds, if the recipients don't like the control, then they are free to use their own money for buying what they want.
Or free to decline to participate in the program that gives them the money.
Or free to vote the source out of office.
Never having used SNAP, I wonder how it works when a shopper checks out a mixed order then presents a SNAP card. Are retailers’ point of purchase systems smart enough to separate out the SNAP eligible items, apply the SNAP balance to those items, then present a remaining balance due (along with a list of the associated items) which needs to be paid with other means? Or is it just buzz, process shut down, cashier needs to figure out what went wrong, everybody else held up for 15 minutes while customer argues with cashier?