Gaining

If it's in a dumpster, it's there for a reason like it's expired or something. If it's there it's likely to make you sick or kill you so leave it where it lies, who knows what kinds of germs and bacteria it's picked up from being in there...gross.

It is a pretty common asumption probably because we're taught that food in the garbage is bad, otherwise it wouldn't be there in the first place. Or maybe it's a health inspection thing where it has to go out if it's past the BBD and it's a hefty financial fine or grounds for a legal claim or something. I worked in food service before and I was taught that we had to toss out the food even it wasn't sold and there was nothing wrong with it, because that's what the Health Board code mandates that we do.

You have to watch for bakery goods like pies in the store, that are 5 days old, as I didn't notice and was sick.
The problem with dumpster diving, is what has been thrown on top of the food and can it be cleaned off.
I was reading about stores donating expiring food to food banks, which was still edible. It might be better to see if you can make a deal with a small store, buy their food and have a weight gain orgy.

I once made bread pudding. The recipe called for day-old bread.

I went to the supermarket and asked for day-old bread.

"We have it," said the clerk, "But I can't sell it to you."

"Can you give it to me?"

He looked surprised, then said "Sure!".