Jumpstart Your 2016: Meet the Man and Woman Who Lost Half Their Body Weight

— -- A man and woman who both lost half their own body weight are sharing their secrets to keeping the pounds off in 2016.

Austin Shifflett, 22, who lost 166 pounds, and Heather Patterson, 43, who shed 127, both appear in People magazine's "Half Their Size" issue, currently on newsstands.

Shifflett said today on "Good Morning America" that he was a target for high school bullies when he tipped the scale at 324 pounds a few years back. It was while he was with a friend who was weighing himself to try to gain weight that Shifflett says he realized he had to make a change of his own.

"He was always trying to gain weight so he was always weighing and I hadn’t weighed for a very long time so I got on the scale and I was about 80 pounds heavier than I thought I was," Shifflett said, adding that moment was his "rock bottom."

Now weighing 158 pounds, he's proud to say he's managed to keep the weight off by swapping out his old diet of burgers and sodas for healthier fare.

"Now I just drink a lot of water, no more sodas," Shifflett said, adding that he drinks low-carb shakes before and after workouts and as a meal replacement.

Patterson, now a health coach, struggled with her weight of 257 pounds for two decades before losing 127 pounds. She says she was motivated by a photo of herself on social media.

"I think everyone has that dreaded moment when they get tagged on Facebook and they don’t know what’s going to show up and this popped up and I just realized that’s what I look like to everybody," Patterson said. "I was tired of feeling bad and looking like that and I was just ready to make a change."

Patterson, who now weighs 130 pounds, says she no longer relies on her old diet of cheese and ice cream.

"Instead of a gallon of ice cream every two or three days, I’ll have some Greek yogurt," Patterson said, adding that she likes to top her Greek yogurt with blueberries. "I’ll have spinach with egg whites for extra protein and for good fiber and bulking it up."

"That’s filling and it’s what I love to eat now," she said.