Most people throw their old food into the bin, but Newsround sent Gavin to meet some people who get their meals OUT of the bin.
Sounds weird doesn't it, so what's it all about?
"If you're more used to getting your grub from the local shops or supermarkets, then spare a thought for Freegans.
Watch Gavin's report on the Freegans
They're more used to grabbing a bite from bins - but it's something they do out of choice rather than having no alternative.
I met up with Paul and Alan, who have lived the Freegan lifestyle for many years.
They reckon supermarkets chuck away lots of stuff that doesn't need to be binned. Freegans go and collect it to eat - or they might recycle stuff that it isn't food.
It's part of a cause to help the environment and reduce food waste. Freegans say the stuff they get from bins would otherwise just go to a landfill site.
MARKS AND SPENCER STATEMENT
"We take the issue of trespassing seriously and are investigating why members of the public were able to access the bins at our Beckenham store.
"The small number of fresh pasta products found had to be disposed of before their sell-by-date because they had been incorrectly stored on shelf instead of being refrigerated.
"This was very unfortunate but does not happen very often. Due to food safety, it is essential that they were disposed of as waste and not consumed."
When I went along to a set of food waste bins, I was amazed at how much the guys found, and at the quality of the food which had been disposed of.
Paul and Alan managed to fill 10 bags from the bins, and they said there was plenty more they could have taken too.
Included in Paul and Alan's haul were bags of fresh pasta that weren't out-of-date. To find out why the bags were in the bin, check out the box on the right with a statement from Marks and Spencer.
Can be dangerous
It might seem pretty easy, but Freeganism can be VERY dangerous.
Anything could be in the bins - including sharp stuff - and some of the food may be unhealthy to eat.
It's also against the law to go into the bins, as the land they are on belongs to the companies that own them.
Freegans Alan and Paul search for the dinner
No-one really knows how many Freegans there are in the UK, but groups appear to be spreading quite widely via the internet. There are certain hotspots where people know food will be found.
Lots of the supermarkets have their own codes of dealing with things they throw out. So for whatever reasons they do get rid of it, it is fair and they are entitled to do so.
But if Freegans continue to make their mark on their bins, it'll be interesting to see what action, if any, the shops decide to take."