1. Some thoughts!!

2. Frequently consumed foods

3. Foods consumed occasionally

4. Infrequently consumed foods – but nutritionally important

5. Sequestration of metabolites in bone, fat and other tissues Plasma pool

6. Kinetics of metabolite appearance and disappearance in plasma Kinetics are metabolite specific Influenced by host genotype Does concentration fall to zero? Impact of repeated exposure?

7. Biomarkers of food intake - follow-up feeding studies (shorter and longer) -Impact of gut microflora - Use of an external marker - Use of stable isotopes to indentify food specific biomarker - Panels or single biomarkers - Quantification (how much orange juice) - Dietary patterns: panel of markers (PHN) -Biofluids: urine and blood; most practical

8. -metabotypes: -How to distinguish? -Numbers necessary to perform. -How many metabotypes? -Genotype: importance: need genotype metabolomic studies to put

9. Run-in diet: - necessary, improves the repeatability of the study - Length will depend on study in question

10. Concluding Remarks - Exactly what you do will depend on the study and questions to be answered