It might if you drink a lot from plastic water bottles. Scitable, by Nature Education recently had an article on epigenetics and changes to the epigenome that may cause obesity from such things as the plastics in our water bottles. The study here was done on identical twin mice. Even though both had 100% the same DNA, their epigenome differed. The effects changed one of the twin mice with the result of being obese and having yellow fur. We also hear of human identical twins where one gets cancer and the other one doesn’t or one is obese and the other isn’t, etc. This is compelling evidence that the story of who we are is NOT in our genes but in which of our genes are turned ON or OFF. Wouldn’t it be nice if we each came with a User Manual that explained which genes does what and how to turn them ON/OFF? What we do know at this point is that eating lots of fruits and vegetables, exercising moderately and lowering stress through yoga or meditation does have a positive affect on our epigenome.