Woodson Merrell said this quote

You replace every molecule of every cell in your body within the course of only one year. I am not being flip when I refer to the new you. It is quite literally possible, no matter how bad you are feeling or eating today, to be utterly transformed in just 365 days. But it won't take you that long. You can be feeling significantly better in just a couple of days and make lasting changes to your health within a month.