I have been reading a good book on grocery retailing called Inside the Mind of the Shopper. I don't have experience in a big operation.

But in general, people buy only about 200 products a year, with 80 being regular products. A typical grocery store has almost 50,000 products, although there are a set of maybe 100 that really sell well. Brands actually pay the grocery stores to carry whole lines of products. That stipend actually accounts for the largest chunk of their profits.

I would say produce shrinks at about 5-10% inside a store. Every step of the process has waste though.

You should just go check it out for yourself. You will likely find piles of pastries, bread, veggies, fruit...could be anything. As long as you don't make a mess, most employees don't care.