The team has done well to research on current solutions and incorporate concepts of gamification into their design. This is a difficult and complex task and students should be applauded for their execution. Hopefully the students will get a change to test out their prototype on actual users and see if their design is effective in motivating students to eat well.
Due to the complexity of designing an application, it is difficult to come out with a working prototype. Perhaps the students could try another approach where they apply 'low-tech' alternatives to achieve the same gamification concepts. A physical logbook/cards could be easier to implement and may yield actionable data.