hello I want to design a game which will help people to know which food is good for their health and which is not so I have thought of working on wrong food combination so please tell me what can I do.

Just to be clear: are you asking us to tell you how to design your game? You must have ideas about how the game might work. Have you thought about the genre of the game? Have you thought about what platform you want the game to run on? Have you played any games that included food?