Cathy Kenworthy has always sought challenging problems—as a McKinsey management consultant; in executive roles at GE, Bank of America, and JP Morgan Chase; and even at leisure. She’s a self-described “fanatic for finding the hardest sudokus and crossword puzzles.”

Today, as CEO of Interactive Health, she leads an organization that’s addressing an especially knotty challenge: high costs and mediocre outcomes in the U.S. health-care system.

Her work doesn’t involve new drugs or diagnostic equipment but, as she puts it, “simple principles broadly applied” to employees of more than 2,000 client companies. “We get hired to help employees be healthier through preventive care,” she explains.

Nutrition, activity level, and tobacco use are three areas of emphasis. “It’s so simple, but so profound,” says Kenworthy. “One area where we can generate tremendous impact is in the prevention of diabetes, which is a major life-altering event. You never stop being diabetic: it affects your longevity, it complicates many other medical conditions, and treatment costs a minimum of $20,000 annually.”

Interactive Health’s data analytics group, which Kenworthy built in her previous COO role, can now show the impact of the company’s work with pre-diabetics through counseling, coaching, and goal setting: 40 percent of them returned to normal health within one year. “That’s a gigantic number, off the charts in any clinical sense,” she says. “And it’s one of the best things you can do for ­someone.”

Kenworthy originally planned to apply that type of compassionate problem solving as a doctor. During her sophomore year at Georgetown University, she was accepted to the university’s medical school, but after working in an emergency room and reflecting on her goals, she chose to major in chemistry and mathematics. She graduated in 1987 and went to work in finance.

At the Sloan School, Kenworthy gained insight from her classmates, who came from diverse lines of work and corners of the world. “I’d come from Wall Street with a total focus on financial engineering,” she says. “Sloan helped me consider the many ways to think about the topic of business.”

Kenworthy and her husband, William, are recent transplants to the Chicago area and have three teenage sons. They enjoy cooking together and are avid hikers, skiers, and walkers.