I ditched med school to start a business

As a premed student, Sean Duffy was caught between his love for medicine and his passion for technology.

A two-year stint at Google (GOOG) just sparked his desire to bring those two passions together, and a year into Harvard Medical School, Duffy, 29, called it quits.

In 2011, he and two friends launched Omada Health, a 16-week diabetes prevention program for those with prediabetes. It costs $500 and provides online resources, like a health coach, and a wireless monitoring device to help users lose weight.

Duffy and his co-founders lived off their savings until they raised $1.2 million from angel investors and venture funds. About 2,000 people will go through the program this year, and Duffy hopes to have between 10,000 and 20,000 people enrolled next year.