How big a role genetics plays in health is still not fully understood. I am of the opinion that it plays a large role but I am probably in the minority here on that issue. Regardless, at this point in time you have no control over your genetics. The only control you have are the choices you make. If you feel that you may be on the short end of the stick in terms of genes, it only makes it that much more important to make healthy choices in regards to your lifestyle. If you revert back to fast food and a couch potatoes lifestyle you will only be that much worse off. You will probably end up in early grave.