Basically a diet (= food composition) analysis does not seem to be such a complicated task, we just have to sort the food according to the trophic sources it comes from. There are, however, three topics we have to think about a priori:

- Definition of trophic sources
  According to what system do we identify and separate trophic sources from each other, and what   "resolution" do we apply?

- Identification of food items
  How to proceede technically in food item identification?

- Quantification of trophic source contribution to diet
  How much does each trophic source contribute to total diet?