I tried a workout and eating plan from Lady Gaga and Katy Perry's trainer: Here's what happened

— -- Harley Pasternak is a trainer to the stars, working with everyone from Lady Gaga to Katy Perry, Rihanna, Megan Fox, Halle Berry, Gwen Stefani, Jessica Simpson and Ariana Grande.

“Good Morning America” paired Pasternak with Nicolette Mason, co-founder of fashion line Premme, to see if the same wellness principles he teaches celebrities could be effective for Mason.

Here is Mason’s experience, in her own words.

I met with Harley for the first time several weeks ago and felt immediately at ease with him.

As a plus-size girl, I’ve dealt with a lot of projection when it comes to fitness. I’m an avid boutique fitness participant, and love my spin classes and barre classes, but I’ve seldom taken a class where I didn’t get unsolicited feedback from strangers or a weird congratulations for “keeping up.” Hello, just 'cause I’m a little bigger than your average cycler doesn’t mean I’m not interested in doing something that genuinely makes me feel good!

I loved that Harley recognized and affirmed me where I’m at: As someone who wants to use wellness tools to manage and improve my health, stress, and anxiety, not to whittle away at my frame. I know that might be foreign to some people … but it has taken me a long time to love myself and my body, and I’m not trying to make drastic changes to the way I look. My goal, instead, is to just feel my best, especially in terms of managing my pain symptoms and stress.

Let’s talk diet, first. I have Celiac disease and fibromyalgia. To my delight, Harley’s plan was so similar to how I already eat that it felt really seamless, approachable and realistic for me to make the modifications to successfully stay on plan. Like me -- Harley doesn’t believe in fad diets; instead, the emphasis is on fresh, whole foods and balanced meals, and if anything, the new plan meant I was eating more and on a more consistent schedule than I was previously doing.

I started every day with a smoothie and filled the rest of my meals each day with delicious salads, fresh vegetables, grilled fish and seafood, quinoa and fruit. It was all so satisfying, and because I was very intentional about balancing my meals with protein, fat and fiber, I immediately noticed how infrequently I felt hungry.

Next, was the fitness component. We both knew I wasn’t going to become a marathoner overnight, but it was important for me to re-frame my approach to workouts. I’ve been so married to my group fitness classes for so long that on days where I was too busy to schedule in an hour-long class or get to a studio, I was foregoing dedicated workouts entirely. Harley introduced me to seven simple, low impact, non-contact exercises that I could literally do anywhere.

Besides the simple seven, we also set a goal of 12,000 steps a day, which were tracked on my FitBit. [Editors' note: Harley Pasternak is a FitBit Ambassador.]

I got kind of competitive with myself and the step number, and felt lucky to already love walking everywhere. Plus, the movement reminders became little benchmarks for me to take breaks from my work, which actually made me feel way more productive, too.

With minimal intervention, the FitBit gave me something that I’ve long desired with my anxiety: Control. It literally gave me a tool, sitting right on my wrist, that handed me the steering wheel to pivot away from my otherwise totally debilitating anxiety. Anxiety attacks have absolutely been one of the triggers to my fibromyalgia flare-ups, and though it’s only been a few weeks, my chronic pain has definitely dissipated a lot.

The verdict: Safe to say, I’m definitely sticking with this approach. It’s so intuitive, honors my approach to wellness and nothing about it is punitive. Living your best life shouldn’t ever feel like a punishment or a chore.

Harley Pasternak's exercise and nutrition tips:

*Note: The diet listed below is a weight-loss diet, totaling 1,650 to 1,800 calories a day. A maintenance diet is, for the average woman, 2,000 calories a day.

1. Eat three meals and two snacks every day.

2. Each meal should be approximately 400 calories total and include servings of protein (at least the mass of your hand), high-fiber whole grains or high-fiber fruits (a handful size), unlimited non-starchy vegetables and two thumb-size portions of healthy fats like nuts, seeds, olives and avocado.

3. Snacks should be between 150 to 200 calories each and include protein and fiber.

'Simple seven' exercises

Do one exercise each day, for about five minutes, following a brief warm-up. Over seven days, you'll work every major muscle group. On day eight, repeat this sequence of exercises.

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Celebrity trainer Harley Pasternak shows 7 total-body workout moves

Pasternak shares toning and tightening tips, from arms to abs.

ABCNews.com

1. Reverse lunge.

2. Superman.

3. Lying dumbbell triceps extension.

4. Stiff-leg dumbbell deadlift.

5. Standing dumbbell curl press.

6. Single-arm dumbbell row.

7. Standing dumbbell side bend.