Updated

Instagram fitness queen Kayla Itsines has never eaten at McDonald’s, but she insists she has had a cheeseburger.

For anyone who has followed Itsines’ journey to becoming an international phenomenon worth a reported $46 million, that tidbit may come as a surprise. After all, the 26-year-old (whose name is pronounced “Its-See-Ness”) has seemingly kept her media profile picture-perfect to fit her role: online personal trainer to 12 million followers on Facebook and 7 million on Instagram. Not to mention, she is an inspirational figure to the countless women who’ve bought into her buzzed-about Bikini Body Guide, a 12-week fitness and nutrition plan that’s set off a slew of hashtags on Instagram, including #bbg (tagged in 5.8 million posts) and #bbgcommunity (tagged in 2.6 million posts).

Does she drink alcohol? It’s “poison,” Itsines has been quoted saying. Has she ever had chicken nuggets? Nope, she told Fox News. Favorite pizza? “Supreme” with lots of veggies and, in Australia, where she’s from, pineapple.

THE 14 HEALTHIEST ITEMS AT YOUR FAVORITE FAST-FOOD RESTAURANTS

What she’d be if she wasn’t a personal trainer: “A teacher!” she exclaimed. What kind? “Fitness!”

Original? No. But when you get to know Itsines in person, there’s no question she's passionate about her work.

“Check this out,” Itsines said, pulling out her iPhone and showing off her newest program, BBG Stronger, on the SWEAT app, for which she’s collaborated with trainers Sjana Elise and Kelsey Wells, two other rising stars in the fitness world. (Itsines’ program teaches women how to incorporate weight machines at the gym into their workouts.) As a huddle of female colleagues passing by congregated around her post-interview, Itsines giddily scrolled through the different features — each move features a digital demonstration by Itsines, complete with a timer to help users stay on track — prompting satisfied oohs and ahs.

Forbes recently named the Adelaide native the most influential fitness personality worldwide — a title she’s earned through promoting her diet and fitness programs, books, in-person bootcamps, and custom merchandise, like yoga mats and foam rollers, on her site.

'ALIEN YOGA': THE TRUTH ABOUT THE WACKY TREND YOU'RE SEEING ON INSTAGRAM

Itsines’ fame, she told Fox News, has grown organically through an online community of women who inspire each other. On her social media accounts, you won’t find body shaming or recommendations to cut carbs (one of the biggest mistakes Itsines sees American women make), but rather, you will see inspirational quotes encouraging self-love, her followers’ side-by-side transformation photos, and snapshots of fruit plates and Itsines’ rock-hard abs. Suffice it to say she's helped lead the charge for the growing body-confidence movement on Instagram.

“I’ve been a female-only trainer my entire life — I started out at a female-only personal training center,” said Itsines, who got into the industry just before her 19th birthday. “I know women, I’m a woman myself, I know what they want, I know how they think, I know how they feel.”

Fox News: You dropped out of college to become a personal trainer, started working at a small gym in your hometown of Adelaide, and joined Instagram on a whim after your business partner and boyfriend, Tobi Pearce, encouraged you to do so. But at what point did you know that you had really created something big?

Itsines: World Tour in 2015 was huge because I got to hear people’s stories who followed my program, and I got to hear how I changed their lives. As a trainer, you sort of think, “Well, you did that because you put in the hard work and you put in the effort.” But they were so adamant in saying that, “No, Kayla, it was you. You gave me the confidence, you gave me the strength.” I was standing there thinking, “This is amazing. This is changing people’s lives.”

Fox News: How do you stay grounded?

Itsines: My family grounds me so much. They’re a big Greek family, and I live a minute from my grandparents, who don’t speak any English. They know what I do, but it’s almost like they don’t mind. They don’t think of me as anything special or as Kayla Itsines from Instagram. It’s just that I’m their granddaughter. They still yell at me when I’m late!

Fox News: You’ve transformed millions of women’s lives. What has that been like?

Itsines: That’s an indescribable feeling. I don’t know if you’ve ever experienced someone coming up to you and saying, “You’ve changed my life,” but you can feel that emotion, and you try to hard not to cry and not to hug them forever.

Fox News: How do you pick the people to feature on your Instagram?

Itsines: This is something I spend a lot of time on, and it’s not necessarily someone who looks a certain way or talks a certain way. It’s someone who’s super inspiring, and I have to be able to go on their profile, see that they’ve done the program, see that they’re a positive person, and see that they actually have a journey that other women can follow and be inspired by.

Fox News: What are some of the biggest mistakes you see women make when they’re trying to change their bodies?

Itsines: One of the biggest mistakes I’ve seen women make in America is the cutting-out-carbs thing. It’s, “I want to look like this” — when really, they should focus on how they feel rather than how they look. It should be: “I’m gonna do this to make myself happier, so in turn, I feel beautiful.” That’s really a mindset I’m trying to teach women.

HOW ONE WOMAN DROPPED 100 POUNDS BY FOLLOWING A FAD DIET

Another mistake women make would be going too hard too fast. As women, we have stages where we get this sudden motivation, we want to do everything — ‘I’m so motivated, I’m gonna go to the gym, I’m gonna work out for hours and hours’ — and they work out, they’re super sore, they can’t maintain it, and they become unmotivated. It’s just about taking things step by step: maybe doing a seven-minute workout and turning it into a 14-minute workout the next week. It’s about slowly building your workout up until you feel good rather than pushing it too far.

Fox News: What’s your advice for someone who is working out and trying to get more physically fit, but is not seeing results?

Itsines: Take a step back and check that they’re comfortable with their training regime, eating the right foods, and drinking enough water. Sometimes, it’s just about eating more and doing less — that’s something that’s a very hard concept to push to women, especially here in the U.S.

Fox News: Have you always been strong and fit? And if not, what challenges did you overcome to achieve the body you have today?

Itsines: I have always been fit — I’ve been into basketball since I was 5 years old. But in terms of strength, that took a lot of building up. I did that through basketball training and training in the gym. However, I’ve always been really, really happy within myself, and that’s what I try to push to women — that I think the more you do slowly, the better you start to feel.

CROSSFIT ATHLETE'S POWERFUL TRANSFORMATION PHOTO PROVES GETTING FIT TAKES TIME

Fox News: Any advice for women struggling with body confidence?

Itsines: We could have the best bodies in the world, but if we don’t feel good on the inside, it doesn’t matter. I always say to people, “Think about the most beautiful person you know.” They’re not beautiful because they have a beautiful body! You don’t say, “Oh my best friend or the person I love the most is so beautiful because her body looks a certain way.” It’s because she makes me laugh, because she’s smart, because she’s there for me. Beauty comes from the inside, and the more that women start focusing on that, the more beautiful people become, including themselves.

Fox News: Your plan is really based on helping women become strong, not skinny — what would you say to anyone who doesn’t think strong is sexy or attractive?

Itsines: Strong is always sexy and attractive! And the word strong — what does that mean? Because strength comes from within, and BBG Stronger is a program that promotes women walking into the gym with confidence and feeling confident as they walk out. When you’re confident within you, it builds and it radiates, and it shines out of you.

8 LITTLE CHANGES THAT CAN LEAD TO WEIGHT LOSS

Fox News: Your Instagram is a serious source of inspiration and support. Can you speak a little to why having that sort of support is so important for people who are on a fitness journey?

Itsines: The transformations are really relatable — you can go onto the page and find someone who looked like you before, or who eats the way you do, or lives in the same country you do. I think that relatability is really nice to have, so you are not looking at one particular person thinking, “Well, I can’t eat that or I can’t do that.”

Fox News: Your programs are big on balance in that they involve weight training, cardio, stretching and resting — and, on the nutrition side, even dessert! Why is this mix so important for producing results?

Itsines: Balance is important in life. It keeps us sane! Why, as women, shouldn’t we be able to have our dinner and eat our dessert? Why shouldn’t we have that? For example, last night I had some pasta and chocolate after, and I don’t feel bad because I eat healthy and I work out. Everything in moderation!

Fox News: Do you ALWAYS eat healthy? What’s something you enjoy eating that people might not expect?

Itsines: Greek cakes! They’re Greek pastries with honey and walnuts. (Itsines’ parents are from Kos, Greece.)

Fox News: You turned 26 in May, and you’ve already accomplished more than most women your age. Do you ever feel like, “Where do I go from here?”

Itsines: No! My clients are the perfect example that age means nothing. Some of them are 40, 45, 50 years old and have the energy levels of a 20-year-old. For me, what’s next is helping more women and learning how I can do that in terms of getting feedback from the community and with BBG. It’s just so exciting.

*This interview has been edited for length and clarity.

FOLLOW US ON FACEBOOK FOR MORE FOX LIFESTYLE NEWS