Hunt says Reynolds' research shows that everyone is looking for quicker and easier ways to prepare dinner. It's a complete, no-fuss meal with no tending and easy cleanup. The original French method called for using parchment paper. Today's recipes use foil, which involves several options. One is using squares of heavy-duty aluminum foil.
Convenience is only one side of the story.
Foil bag cooking allows foods to cook in their own juices, eliminating additional fats. Also, several ingredients can be cooked together in a single bag. Making a veggie medley is simple, even if you have to make the bag yourself. The only drawback to packet cooking on the grill is that the food doesn't have that grilled flavor. It's just not the same as seeing the charcoaled lines from the grill.