First things first, print out the food activity cards. (There is a back side to each card with nutrient information. If you're able, you can paste the nutrient info to the back of the corresponding card, but this is not necessary for the games.) If you don't have a printer, write down the food on a piece of paper., and write the coresponding food group on the other side of the paper.
Once you've got your food activity cards, sort them into different food groups over and over again. Knowing what foods go in what food groups is key. You can sort them within a simple relay game. Set-up designated sections for the cards in a star formation; fruits, vegetables, grains, protein, dairy, extras. Put the cards in the middle of the star. Put your group in the middle of the star. Have each person take a turn and select one card. Then place that card in the correct food group pile. Don't worry about making mistakes during the game. Evaluate the piles when all the cards are sorted, then discuss and make corrections that need to be made.
Now proceed to play the following games throughout this week. Modify them as you see fit.