Can DNA testing help create a personalized lifestyle?

May be. It is possible, in a limited way, to test for disease susceptibility, e.g., app e for alzheimer, brca for some cancers, hnpcc or fap etc. Efforts are underway to identify additional markers. However knowing the markers and making the "lifestyle" change are not linked. People with known family history of diabetes continue to be overweight and not take any action to reduce their risk.