The present invention provides networks and method for linking consumers and nutritional pharmacogeneticists offering personalized nutritional information through a central network site. The network includes a central integration site through which network members communicate with each other. The central integration site stores two or more databases in the storage medium. The databases store biochemical marker data information, nutritional and/or drug data information including a record for association and effect of nutrients with a particular biochemical marker, and/or drug. The network of the invention provides individualized nutritional diagnostic and treatment to consumers on the basis of their genetic test results.