I rarely, if ever, eat fast food so if I do, I want to make sure I'm getting the best stuff. 

According to Reader's Digest, the best way to ensure you get the freshest food from your favorite fast food chains is to ask for a receipt. Former employees of McDonald's say that they are trained to give little extras, like the hottest batch of fries, to customers who ask for one. Why? Because this is what the 'mystery shoppers' do.

Think about it - if you're being paid to stealthily visit McDonald's and rate your experience, you ask for a receipt so you can be reimbursed later. So employees are taught to serve those who may give hints that they are these 'mystery' customers first and often give them the freshest food to boost their rating.

The fast-food giant hasn't confirmed if this is true but I do know that after years of being a waitress, we were always taught to look for certain things that may hint someone was from a newspaper, or a health inspector, or checking that wait-staff are checking I.D.'s before serving alcohol so it wouldn't surprise me if there was some truth to this.