If the object is to lose weight, obviously you do not want to replace those calories. Make sure the food you eat is nutritious with lots of vegetables, fruit, and lean protein because to lose weight you don't want to waste your calories on junk food that gives you nothing of value and just revs up your appetite.
You have to eat less than you're burning every day, if you want to lose, so you eat back the calories used during exercise, you won't lose weight, if that's your goal. It's giving you those extra calories to maintain your current weight.