I have found a few favorites in searching for meaningful learning activities on nutrition for my kids. There is an adorable set of lessons called Little D's Nutrition Explorations that teaches about nutrition in a fun and memorable way. It has cute characters and stories to go along with it. I used this in our homeschool co-op one year and the kids loved it. I also really like the site Choose My Plate. File Folder Fun has a couple of nutrition related file folder games that my kids enjoy.
Here are a couple of books related to nutrition that we have and love :
Karyn is a homeschooling mom of three kids. She grew up in S. Florida, but has lived out west since college. She is a former Home Ec. teacher and loves cooking, running, reading, sewing, singing, gardening, blogging, teaching, & being with her family! She write two blogs- Teach Beside Me is a homeschooling blog and her other one is a food blog.