How Hairstylist and Marketing Executive Each Shed About Half Their Body Weight

— -- For Conner Rensch, weight has been a lifelong struggle.

“I knew I was overweight when I was six years old,” Rensch, now 25, said.

A chronic overeater, Rensch dieted for the first time when she was in the third-grade.

By the time she was in the eighth-grade, Rensch weighed more than 200 pounds, and she tipped the scale at 271 pounds after her freshman year in college.

She knew she had to do something. She looked into the mirror and resolved to not be overweight anymore. Through determination and hard work she lost 130 pounds.

Her story, and the stories of others who’ve also shed a lot of weight, is detailed in People magazine's special "Half their Size" edition.

Rensch, a hairstylist, told “GMA” she resolved to change the way she ate. For her, a typical dinner consisted of three big bowls of creamy chicken pasta with fried chicken, a small loaf of sourdough bread and a piece of cheesecake.

Now, her typical dinner is ½ a cup of whole wheat pasta, blended cottage cheese as a sauce with a little pepper and salt, 4 ounces of grilled chicken and a little broccoli.

She eats five to six small meals a day to keep her metabolism going, and tries to balance protein, fat and carbs as each meal.

She also follows a strict exercise routine that includes weight-lifting four days a week. In addition to modifying her diet, she did a lot of cardio, kickboxing and interval training to lose the weight.

Rensch went from 271 pounds to 141 pounds, and says she has a whole new level of confidence about dating and her work.

"I’m just happier," Rensch said today on "GMA." "I can be myself without this covering me up. I think that’s the best thing about it."

For 40-year-old Mark Bryant, weight didn’t become a problem until later in life.

A sales and marketing executive for a dietary supplement manufacturer, he never exercised any discipline in his diet.

“When I graduated from high school I was about 185 pounds … over the next ten years gained about 250,” the married father of three told “GMA.”

At his heaviest, Bryant weighed 442 pounds.

“Lunch would typically be a couple of hamburgers and large fries and a milkshake and then dinner would be an extra-large pizza with garlic butter sauce and ranch,” he said.

His turning point came after he went to the hospital suffering from chest pains.

Bryant was only having an anxiety attack, but a cardiologist gave him a wakeup call.

“The cardiologist told me, ‘If you don’t change your ways real quick, you’re not going to live to see your daughters get married,’” he said.

The scare motivated him into changing his life, and he lost 261 pounds.

Bryant, who now weighs 181 pounds, started off by counting calories.

Now, instead of an extra-large pizza, his dinner consists of lightly sauced, grilled teriyaki chicken along with a big plate of steamed broccoli topped with a light olive oil drizzle and Parmesan cheese.

Like Rensch, he, too, works out. He lifts weights, bikes and does high-intensity interval training on the bike. His regimen includes about two hours of training a day, four days a week.

"It was a gradual process," Bryant said of his transformation.