This looked like a fun, engaging way to have young children explore the affects of food on their bodies.
Link: http://www.intel.com/content/www/us/en/education/k12/project-design/unit-plans/healthy-eating.html

"Some "projects" border on busywork. Others involve meaningful inquiry that engages students' minds."
~John Larmer and John R. Mergendoller

http://www.ascd.org/publications/educational_leadership/sept10/vol68/num01/Seven_Essentials_for_Project-Based_Learning.aspx