Dublin Operation Transformation leader Louise Ormsby is determined to shed the pounds in the hopes it will help her to get pregnant.
Louise (34) from Adamstown has been married to her husband Will for four years and is unhappy at her current weight of 14st 7lbs as she wants to start a family.
"I didn't realise weight affects your fertility and that fertility clinics won't even entertain you if your BMI is over 30," Louise told the Herald.
"When you're overweight - that's it, they won't treat you and that's what happened to me," she continued.
"My BMI is 34.4 and in August, we were back and forth to certain IVF clinics. They just said you need to lose the weight and then come back and see us..
"It may not be a factor but they wouldn't recommend for me to get pregnant being overweight so they told me to come back when my BMI was less than 30," she added.
Louise was chosen to be a leader before Christmas and admits she's keen to get started on her new health and fitness regime - and to quit her 20-cigarettes-a-day habit.
"I'm really determined but I'm anxious about the reaction and everyone knowing everything about me - that's the only thing I'm nervous about," she said.
"I think I'll do OK at the diet and with the exercises but I'm not so sure about the smoking.
"I'll give them up but I think I'll find that the hardest when I'm completely stressed out or something like that.
"I think I'll go cold turkey, I really want to give them up and it can't be that bad if other people can do it.
"I'm hoping I'm going to be so busy I won't even be thinking about cigarettes," she added.
Louise also revealed that her husband Will is determined to help her all the way and is even planning on undertaking the same lifestyle change.
"My husband is great, he's going to help me along," she said.
"He's 100pc behind me. Rather than cooking separate meals, we're going to go on the same plan."
"I don't view it as a diet, it's more of a lifestyle change.
"It's not going to be rabbit food, it's more low fat choices of regular meals, like spaghetti bolognese from scratch," she added.