Ok, that makes sense. Thanks for the work you do in a difficult field. But honestly I think you're overly optimistic about a potential business case for this idea.

I apologize this is likely gonna be long.

Loss leaders are designed to pay for themselves over an average of other items bought so the store is never actually losing money. Some fast food places do this with food vs drinks. The cost to them for a drink is a few cents but they charge a couple dollars. That's a 200%+ return in profit on the drinks which covers the cost of the drink and the margin of loss on the food plus some. Ketchup isn't gonna do that. Things people might buy to supplement aren't gonna do that. (If we were talking about lowering the cost of potatoes to get people to buy ketchup and condiments for them? maybe?) Labor is a huge expense, people cost more than their salary (401k, benefits, etc.) If someone makes $20K a company likely calculates their cost at $40K. So three full time employees to work the counter, work in back, etc is like $120,000 a year (assuming full time employees at $10 an hour) just in labor costs for 1 store. You would also need regional managers, lawyers, etc to run the program and they cost a lot more, plus the regionals travel expenses etc. Loss leaders at a grocery store isn't gonna even dent that cost. Add to that the overhead for the building, storage, upkeep of the space. They might make some of it back on tax write-offs but why do all that when I can give $.25 off the profit on a can of beans to charity and write that off without the additional liability/cost of a food bank? I can give cash, write it off, and use it in my ads to appear less capitalist greedy oversteer. When I can use the space a food bank would take up to sell overpriced sugar? That's lost opportunity cost on that floor space and that could cost $100,000+ a year depending on how much space the food bank would require. Per store. That's millions a year for sure to get back? Not much from the companies perspective.

A charity branch? No. Food banks that they run out of every store? Yes. From a business perspective it doesn't make any sense at all, that's why you've never seen one even at more "progressive" grocery stores. A charity branch will make cash donations, set up "sales for charity" schemes, and do what some people have already commented and donate the food to local charities. All for that sweet sweet tax write off money. The logistics of that transfer with meat plus the additional liability is why you're unlikely to see them donate it even if the food bank has a fridge. The issue is with getting it from the store to the food bank.

You're getting a lot of pushback from people in this thread because your stance that a grocer would do this voluntarily is, in a business sense, wildly optimistic and bordering on absurd. The only real path I see towards this idea (which I do think is an ideal that's worth striving towards) is if the government mandated it. The issue there (in the US, I'm US based and understand that system best) is that it would likely have to be a state mandate, and while some states (CA) might be open to it, others (TX) likely won't. You could try to force it through from a federal funding directive like they did with highway money and the drinking age being standard (drinking age is set by the state, they've just all been bribed by the feds to make it 21). But you'd get a lot of pushback from companies who would be losing millions+ every year on the requirement and we all know the outsized impact companies have on our money grubbing politicians.

So while I like you're idea in principle I don't think it's realistic at all since youre wanting companies to do it voluntarily. It might be possible to force them to do it involuntarily but it would be a bitter, bloody fight and the populace would need to want it overwhelmingly which I don't think would be the case. You'd have my vote in favor for what it's worth.