Though it's not technically "meat," vegetarians in the UK are boycotting popular chocolate bars in response to news that Masterfoods, which makes candy bars like Mars, Snickers, Twix, and Milky Way, will be adding an ingredient called rennet to the ingredients. Rennet is an enzyme taken from the stomach of baby cows and used to make whey. Up until now, the candy bars have been made with a non-animal alternative, and the change seems to be a cost-cutting measure.

So if avoiding any type of animal-based product is important to you, look for candy bars that have a "use by" date earlier than October 1. Any dated later than that will have rennet in them.