The next inclination would naturally be to say "Well, you just force the growing of rice, beans, potatoes, and broccoli." You have now landed on a planned economy, which doesn't work very well.
So healthy staples can't actually be "free for all". I do think that providing the food directly for people who need it would be a better idea, but you get associated issues of government price-fixing and dumping of lower quality food-stuffs.
Federalism is all about experimentation. One of the features is to permit the autonomy for local governments to attempt local solutions to the specifics of the problem as it is faced locally. There may be something to be said for a central (federal) facilitation of local programs, but this almost always takes the form of funding.
If anything, the argument against it would be picking and choosing industry winners: pistachio, avocado, cheese, meat markets would find it unfair.
Cuz I'll be honest, with $1000 a month in cash, I would eat less healthy than $500 cash, and $500 in healthful grocery credits.
Im sure Im wrong, but wouldnt it make sense to start with like "all rice, bean, potatoes, and broccoli consumption at the personal level is free" and start with a food stamp / ebt that buys unlimited of something very specific? It wouldnt be a currency thats worth trading to other people, landlords couldnt collect ebt credits in lieu of rent, because everyone would already have unlimited.
I guess I dont understand why UBI proponents think CASH is the best idea, compared to more specific tiers like "600 for healthy food, 100 to treat yourself, 300 for xxxxx." I guess I also find it confusing why it has to be nothing or 100% without any sort of gradual experimentation. Why does the program have to immediately ramp up to the full plan?