After losing 40 lbs. – and keeping it off – Locke, 33, will co-host a lifestyle show with Project Runway's Tim Gunn and celebrity trainer Harley Pasternak. It's tentatively titled The Revolution and will air on ABC.
"It's lifestyle transformation, from health to family, weight, food, kids, bedroom, style … the whole nine yards," she told PEOPLE at the Cinema Society and Alice + Olivia premiere of The Art of Getting By Monday in New York.
"After American Idol, I started my own transformation journey from Lane Bryant to Celebrity Fit Club to Jenny Craig," she said. "I've lived it. I'm an expert."
"I know the struggle," she added, "and I'm looking forward to helping others."
How did Locke maintain her weight loss?
"You do it one day at a time," Locke, who eats lots of vegetables and maintains a healthy diet, said. "And you do it by being gentle on yourself and knowing that it's a journey. And it's not a sprint. It's going to take some time."