dr. dan reardan is head of a dna testing company that aims to answer the question. for $250, you can buy a testing kit. they spit into a test tube, mix it with a preservative and mail it to the fitness gene laboratory and scientists then test 48 variations. >> if the goal is getting fit or losing weight, we can guide people using their dna as a background. >> for dustin, it confirmed things he suspected. he has a tendency to gain weight but responds well to exercise. somsome results are confusing ad cancel each other out such as his response to saturated fat. >> for deanna, it's tougher for her to lose those few extra pounds, but high intensity training should help. >> we caught up with kelly. her results were what she expected. >> she had two copies o of a gene looking at muscle strength, her results recommend resistence training. she thought fitness training was interesting but there are caveats on the report, such as no gene acts alone. >> the science is still young. there is a lot that they don't understand about how all of these things interact. that's why ther