What would the user do
User Joe would track (whenever he does not forget) what he eats. The software would try to model his average nutrition intake, through heuristics and a database of nutrition facts. He would also have to decide diet recommendation he'd like to follow. i.e vegetarian, vegan, low-carb, no gluten etc. and which micro-nutrition, vitamins & supplements recommendation he trusts. (We can use data from this project to design recommendations)
What would the user get
The software would create, according to the users preferences, a list of supplements and ingredients the user is supposed to eat to reach his targeted nutrition needs.
The black magic
The used magic is tracking down all possible inter-ingredients relationships. In other words: the effect a ingredient has upon other ingredients, i.e your body does not absorb iron very well in absence of vitamin c. By using these relationships of ingredients it would be possible to create a menu plan that maximizes nutrition absorption with the smallest possible amount of food. Thus increasing the efficiency of eating.