Meghan Trainor’s fitness coach has responded to the intense discussion surrounding the singer’s recent transformation, revealing that the ‘All About That Bass’ star’s results go far beyond any single medication.
The Grammy-winning singer, 31, turned heads earlier this year when she appeared at a TV premiere alongside husband Daryl Sabara, showing off a noticeably leaner and more sculpted physique. The appearance followed months of openness from Trainor about her body image journey — one shaped by pregnancy, postpartum recovery, surgery, and a renewed commitment to health.
Trainor, who welcomed two children via caesarean section, previously admitted that her changing body and self-image made it “harder” to write songs about self-love. She described struggling to feel comfortable in her skin before deciding to make significant changes, including breast implants and a lift.
“I hated what I had before,” she told Entertainment Tonight, explaining that her surgeries were part of a larger goal to “be the healthiest, strongest version of myself for my kids and for me.”
In addition to lifestyle changes, Trainor also revealed that she began taking Mounjaro, a GLP-1 medication designed to help with weight management, under medical guidance.
“I used science and support (shoutout to Mounjaro!) to help me after my 2nd pregnancy. And I’m so glad I did because I feel great,” she wrote on social media.
That admission drew widespread debate online about celebrity use of GLP-1 medications – especially given Trainor’s history as an outspoken figure of body positivity. In fact, her social media comments sections have since been flooded with criticism from people claiming she is a “hypocrite” for losing weight – with people using lyrics from her his song ‘All About That Bass’ to jump off.
One Instagram user commented: “Oh so we’re not all about that bass no more?” While a second added: “So you no longer have all the right junk in all the right places now? Where’s the boom boom that all the boys chase?”
But now, Trainor’s trainer Bella Maher has stepped in to clarify what really went on behind the transformation.
Maher, who has trained Trainor through her postpartum recovery, shared a heartfelt Instagram post featuring before-and-after photos of the pop star, calling the process “one of the most meaningful parts” of her career.
“Watching her transform from the inside out has been one of the most meaningful parts of my work,” Maher wrote. “She did so much of this on her own before ever introducing a GLP-1, and even after starting it, the medication was simply a support, not the reason for her results.”
Maher continued: “GLP-1s can be a powerful tool, but they’re certainly not a transformation plan. SHE is the reason this worked.”
She credited Trainor’s consistency and mindset for her progress.
“She prioritised strength training, protein, intention, structure, and showing up even on the days she didn’t feel like it,” Maher added. “She built this. She earned this. And now she gets to live in a body that supports her for life.”
The post was accompanied by a mirror selfie of the pair flexing side by side, celebrating Trainor’s dedication and resilience.
Why Exercise Still Matters — Even With Mounjaro
Experts agree that combining medication with structured exercise delivers the best outcomes. Dr Jennifer James, a physiotherapy lecturer specialising in physical activity and obesity, explained that GLP-1 users who pair the treatment with regular exercise see better long-term results.
“Research has found that when formal exercise is used in conjunction with a GLP-1, it produces superior outcomes compared to placebo, medication alone and exercise alone,” said James, via Women’s Health. “Those using exercise and a GLP-1 together had a greater body fat percentage change than the other groups, as well as a reduction in waist circumference, and when they finished their medication, they didn’t regain as much weight.”
She noted that because GLP-1s can cause muscle loss, building and maintaining strength is essential.
“Weight loss impacts all tissues, not just fat,” James explained. “You can’t specify that your body only loses fat mass. This includes bone and muscle — which is particularly important as women age and hormonal changes accelerate muscle loss.”
That’s where strength training becomes vital. Dr Saima Ajaz, a lifestyle medicine physician, says resistance work is non-negotiable.
“Two-three sessions per week, targeting all major muscle groups — legs, hips, chest, back, arms and core — can help preserve lean muscle mass,” Ajaz advised. “Movements like squats, lunges, push-ups, rows and planks are all good for preserving muscle. Add balance and mobility work like Pilates to improve range of motion and help you activate more muscle during strength exercises.”
She added that cardiovascular activity — such as walking, cycling or swimming — remains important for overall health, but “strength and resistance training is a non-negotiable.”
Trainor’s honesty about using both medical support and discipline didn’t sit well with some fans who’ve followed her career since ‘All About That Bass’ became an anthem for body positivity a decade ago.
However, in a recent live performance, she even poked fun at her evolution by altering one of the song’s most iconic lines — swapping “It’s pretty clear, I ain’t no size two” for “It’s pretty clear, I got some new boobs.”
Still, her journey has been about more than just appearance. Maher’s praise underlines a shift toward sustainability and self-care, built on routine, structure, and long-term health.
“She prioritised strength, protein, intention, structure, and showing up,” Maher reiterated. “That’s the real transformation.”
As debate around GLP-1 medications continues, Trainor’s story reflects a middle ground — one where science meets hard work, and where confidence isn’t about size, but about strength, stability, and showing up every day.
And according to her coach, that’s exactly what Meghan Trainor has done.
Featured image credit: Instagram/MeghanTrainor/malibubodies
