A&E Network presents a groundbreaking new series that follows personal fitness trainers from across the country as they undertake the most extreme weight-loss experiment ever: by forcing themselves to gain weight, they aim to better understand the struggles of their obese clients as they lose the weight together.

In 2012, professional fitness trainer Drew Manning saw that there was a disconnect between him and his out of shape clients. They claimed he couldn’t understand what they were going through. So he purposely gained 75 pounds to understand the struggle to lose it. It was the hardest thing he’d ever done, but it changed his life forever.

Fit to Fat to Fit follows 10 trainers at the top of their game who will embark on Drew’s challenge; agreeing to intentionally pack on the pounds by indulging in an unhealthy diet and completely refraining from exercise in order to transform from fit to fat.

During the weight gain process, these elite trainers around the country will document the radical effects of watching their healthy bodies deteriorate. Everything from their mental stability and physical energy to their personal relationships will be challenged. After four months of gaining weight under medical supervision, each trainer will rejoin their client and together they’ll begin a four-month transformation from fat to fit.

At the end of each episode there will be a final check-in to reveal whether or not each trainer and client reached their weight loss goals. This highly emotional and inspiring journey will explore the highs and lows of a rigorous process many Americans battle every day.