Kathryn Thomas is the first to admit that she fell off the wagon over Christmas. Just like the rest of us.

“I have been in much better shape than I am now,” she says. “I was actually pretty sick in October, and I took my foot off the gas, and then coming into Christmas it was everything else. I am like everybody, I fall off the wagon. I have days when I feel better in myself, and days when I don’t.”

While Thomas doesn’t believe in new year’s resolutions per se, she says January is as good a time as any for making a lifestyle change, or simply working off the excesses of Christmas.

“This time of year, people are tired, they are sick – we see how many people are on trollies at the minute with the flu. January is a good time psychologically to get yourself back on track and start again.”

Guilt is another thing she doesn’t do. “I think we are too hard on ourselves. There is this notion that if you have a bad week or two that you undo all your good work. That’s not fair: it’s about what you do most of the time.”

The RTÉ presenter's name has become synonymous with health and fitness thanks to fronting the hugely popular Operation Transformation, as well as the intense boot camps she hosts throughout the year. Yet she acknowledges her lifestyle isn't holier than thou.

“I am not an all or nothing person,” she says. “I try and do five days a week where I am clean, but I would, at the weekends, eat what I want. When I go out for dinner, I got out for dinner – I have a starter, I have a main course, I have cheese, I have wine. I love my food and I always have done, which means I have to watch my diet.”

All about health

Thomas (38) says her personal goals have changed. Whereas before it was about looking good in a bikini for No Frontiers, the travel show she presented for 10 years, now it's about health, wellness, and longevity.

“My focus has shifted, but it’s really only in the last five years that has happened. I am in my late 30s now. I see my friends having babies, my parents are getting older. For me now it’s about health. The older you get, you realise that getting into the skinny jeans is what we might want. But I think the focus needs to be less on weight loss and more on health gains.”

Operation Transformation certainly gets that message across. While the weigh-ins are part of the story, participants are often given some stark home truths about the state of their health.

"Some people might want to buy clothes that fit and look good and feel comfortable," Thomas says, "but Sean on this series is 22 and he is being told by Dr Ciara Kelly that he is on the verge of osteoporosis, developing fatty liver . . . That's when you think no 22-year-old should have to worry about that, but that's the reality."

Support is key, which she says is one reason why she established her Pure Results boot camps.

“I don’t think anyone can make huge lifestyle changes without support, whether it’s from your partner, or your mum and dad, or your friends. It can seem daunting if you’ve been off the wagon for so long and you are maybe a few stone overweight; going into a gym can be very intimidating. I wanted to create an environment where it is supportive and have people working there who have been through that experience themselves.”

Thomas got engaged last year. A looming wedding is often the instigator of a serious weight loss plan, but she says she won’t be that bride.

“I’ve seen brides, with the stress of the dress, and being the focus of attention that day, losing a stone or two and not looking like themselves. I get it, and it’s very easy to fall into, but there’s no way I’ll be doing that.”

Kathryn Thomas's top 10 tips for getting healthy in 2017
Take small steps: Don't look too far ahead. When people think about losing weight, they think about losing a stone, not losing a pound.
Make time: Make time for exercise. Try and squeeze in a walk at lunchtime in work. Use your Facebook or your Twitter scrolling time to actually get out and get active.
Use technology: Using your FitBit or an app like MyFitnessPal on your phone is a way of monitoring your activity. We often want someone to tell us how to do what we are unsure of ourselves."
Enjoy your exercise: Find an exercise that you like to do – don't go running if you've never ran before and you hate it. Do something that you do like, as there is something for everybody, whether it's dancing or cycling or hillwalking or pilates. Everybody is different and every body is different. What works for someone else might not work for you.
Make it social and fun: Have a day a month where you get your mates or your colleagues or your family, get together and come up with a fun activity. This doesn't need to be about physical health: it could be focused on mental health.
Get creative with vegetables: Play with your veg. Find something you like and look at what you can do with it. I have realised I am addicted to cauliflower. I never knew it was so versatile, but it is gorgeous when it is roasted."
Spice it up: Your spice rack is your friend. Everyone should invest in a good one – they are key to keeping food interesting. Read up on what you can do with them."
Get souping: Soups at this time of year are perfect. They are quick and easy and will stop you reaching for an unhealthy snack as they are so filling."
No cup of joe: Avoid the coffee shops. We run in and have a skinny latte, and anther flat white – that adds up. Try limiting your coffee, but there's also temptation when you're standing in the queue to grab a brownie or a croissant."
A great soundtrack: Music is so important when it comes to exercise. I have different playlists for walking the dog, for running, for weightlifting. Music helps our mood so have fun with your playlists. Podcasts are great too.

Win a week-long Pure Results bootcamp retreat with Kathryn Thomas
To mark The Irish Times's Get Healthy month we have teamed up with Pure Results boot camp to offer one reader a place on a Pure Results seven-day, all-inclusive boot camp retreat.
Get fit, get healthy and meet like-minded people on the stunning Wild Atlantic Way in the luxurious Parknasilla Resort and Spa in Sneem, Co Kerry.

The camp includes accommodation, meals and snacks, a consultation with a head nutritionist, activities including hiking the Old Kerry Way, day trips to Gleninchaquin National Park, Derrynane beach and night kayaking as well as classes including circuits, boxercise, metafit, aqua fit, kettle bells and orienteering.  Well-being education sessions include life coaching, cooking demos, nutrition workshops, and mindfulness classes, plus you're given a two-week aftercare programme. To be in with a chance to win, enter here