For Catherine “Cate” Laughlan, coming home from California for the holidays and resisting the urge to eat the Christmas cookies she saw everywhere was one of the biggest challenges of her new life.

“What I would have done in my previous life was just indulge in all of them,” the Ransomville native said. “At first, I wanted to throw myself on my bed and have a temper tantrum because I wanted to eat it so bad.”

The 5-foot, 2-inch blonde, who weighed 247 pounds and had trouble walking, considers every bite more carefully now that she is a contestant on the 14th season of NBC’s “The Biggest Loser” reality show, which premiered last week and has a new episode at 8 o’clock tonight.

A tempting sugar cookie now makes the 28-year-old woman think about how much she has to jog to work off the 120 calories.

So that treat did not make the final cut in her spare Christmas feast of 6 ounces of grilled turkey breast, a cup of roasted broccoli and a baby spinach salad with a teaspoon of olive oil and balsamic vinegar.

“The more you say, ‘No,’ the easier that gets,” she said during an interview as an NBC publicist listened in.

Managing diet and exercise, and tough fitness coaches, are among the obstacles that overweight contestants work to overcome as the show unfolds. Laughlan and 14 other competing cast members, who live at a spalike ranch in California, are divided into three teams led by different trainers and compete for prizes, including a $250,000 grand prize, by seeing who can lose the most weight. As the weeks go by until the finale in March, people get eliminated when pound-loss totals fall behind.

By the first two episodes of when the show premiered last week, Laughlan had lost 17 pounds. When she talked last week before heading back to Los Angeles, she said the experience has been liberating.

“I didn’t know what a 28-year-old body should feel like until I got started with ‘The Biggest Loser,’ ” she said. “I was so overweight, my legs would burn.”

Now she runs four times a week and is getting closer to her goal of being able to work out with her marathon-running brother. “I’ve always dreamed of running with him. I just never could keep up,” she said. “He was the one who encouraged me to get out there on the road and just try, even if I could … only make it from one telephone pole to the next.”

Laughlan, a 2002 graduate of Wilson High School, said she was one of the bigger girls there, wearing a size 16. In the years that followed, her weight grew. Last May, she finished her undergraduate degree in human resource management at Niagara University, but she felt limited and unhealthy. Recently, a doctor told Laughlan that her legs were swelling because her body wasn’t strong enough to pump out the fluids.

“I don’t shop,” she said. “I don’t go to parties and events.”

Last year, after a friend noticed that there were auditions in Detroit, another friend drove her to try out for the show that she had wanted to be a part of for so long. “I could connect with the contestants so much,” she said. “I could feel their pain.”

Once she got to the ranch, she took pleasure in luxuries such as heading to the pool at 5 in the morning when mist was coming off the water, the moon was out, and she could feel the adrenaline kick in as she swam in the cold water.

The show also is famous for more unpleasant realities: intense workouts and trainers who yell when contestants struggle. In the first episode, Laughlan consoled and hugged a man who was berated for falling off the treadmill. “Get him out of my gym now!” shouted trainer Jillian Michaels, who is lean, muscled and well-known for her abrasive approach.

Laughlan’s Niagara Falls trainer, Gail Vizzi, said her style is a mix of toughness, energy and humor. “Never did I yell,” she said.

Still, when Laughlan was home for the holidays, it was obvious to Vizzi that the show has had a powerful effect.

“I had worked with Cate for a few years. Mentally, she wasn’t ready,” Vizzi said. “When all of this happened, she was ready. When that switch goes off and they’ve had enough and they’re ready to do it, there’s nothing that stops them.”

Laughlan’s new competitive spirit reinforced for Vizzi one of the fundamental secrets to life-changing weight loss: It won’t happen until a person sets their mind to it.

Before Laughlan left Saturday to go back to California and her trainer for the show, Dolvett Quince, her abdominal muscles were obviously stronger, and she was doing well with crunches that involved punching at pads as she pulled herself up. “She was very excited to go back and show him,” Vizzi said. “I’m hoping he’s thrilled for her.”

Laughlan says her career ambition is to get a job in the fitness industry to help others lose weight.

“Being a part of ‘The Biggest Loser’ makes me feel like finally I am getting off the sidelines and participating in my life,” she said. “What I want to achieve isn’t so much a number. What I want to achieve is state of mind.

“The state of mind that I want to achieve is a place where I can go to bed at night and be proud of everything I accomplished in my day. ... Before ‘The Biggest Loser,’ I kind of sat back and let the days roll on.

“What ‘The Biggest Loser’ has given me is a path.”