"I don't have to convince somebody that they want to buy or sell a house," Stephanie Kohl said. "They're coming to me to help them do it in a smart way."

Tami Schiltz can't peg her insecurity and nutrition struggles to a specific moment. Certainly, being called a "whale" as a 138-pound high-schooler didn't help. "You have that one comment that just sticks out at you, and...