Jeffries, who works at Aetna, has lost 50 pounds and dropped eight dress sizes in the last two and a half years through a program at Aetna run by Newtopia, a company that provides wellness services. She has access to one-on-one coaching and a personalized diet and exercise regimen, but Jeffries, 46, credits her stellar results to a DNA test offered as part of the program. (Greenfield, 2/1)