" Genetic researchers decided to follow a group of 200 Spanish teens who were on a 10-week quest to battle the bulge. What geneticists discovered was that they could actually reverse engineer the campers’ summer experience and predict which of the teens would lose the most weight depending on the pattern of methylation—the way their genes were turned off or on—in around five sites in their genome before summer camp even began.7 Some kids were epigenetically primed to lose the bulge at summer camp while others were going to keep it on, despite diligent adherence to their counselors’ dietary protocol. "

― Sharon Moalem , Inheritance: How Our Genes Change Our Lives—and Our Lives Change Our Genes