I'm all about avoiding food born illnesses since it seems like, if someone is going to have a problem with rotten food, it's going to be me. Maybe it's just my tender tummy, but I tend to follow the "use by" and "sell by" dates religiously, just for that very reason.
According to this article in Slate, Ignore Expiration Dates, the author makes a reasonable argument that the dates stamped on our food are really just arbitrary.
University of Minnesota food scientist Ted Labuza explained in the article that expiration dates address optimum freshness (rather than safety) and tend to be extremely conservative. Why so conservative? Well, because the dates need to account for how the laziest people with the most undesirable kitchens might store and handle their food. Then the manufacturers test their products based on those criteria.
For example, for perishables like milk and meat, people who go straight home and refrigerate their groceries as soon as they get home will have a 3 - 7 day grace period after the "sell by" date. Because many consumers take their food on a tour of the city, leaving it in overheated cars or making additional stops on the way home and then store it in an overly warm fridge, the life expectancy of the food is reduced. This results in a shortened date span to accommodate the least common denominator.
More importantly, there is no federal mandate on food freshness dating. It's an entirely voluntary practice that's been adopted by producers and manufacturers to put on their products as well as grocery stores. This serves two purposes. On one hand, it gives us a sense (falsely so in some cases) of security about a given product's freshness. And on the other, it's possible that the manufacturers and stores are listing dates that expire prematurely to ensure that consumers replace products more frequently than they probably need to.
What's a consumer to do? Well, you really have to use your judgement. I wouldn't skimp on foods that, when they go bad, take you down with them. If that milk looks or smells weird, don't drink it. Is it covered in mold, slime or other unidentifiable growths? If so, depending on the type of food, either cut off the offending piece or throw it out (preferably composting it) altogether.
Still don't know what to do with it? Here is a series of videos explaining how to tell when food goes bad, including How to Tell if Your Bread has Gone Bad and How to Tell if Your Leftovers Have Gone Bad. So, now you don't have an excuse.
What do you think about expiration dates on food? Do you eat packaged or canned foods years after the pull date? If it looks and smells okay is it fair game?