The skipped meals and scarce calories soon showed when Kildunne returned to organised rugby.
She suffered a stress fracture in her knee.
“That was probably just because I didn’t have the muscle to take the force of running and the intensity we train at,” Kildunne reflected.
As she attempted to lift weights in the gym, involuntary tremors would set her limbs shaking.
“It was just because I had no energy. I had nothing in me to fuel,” she added.
As she switched into fifteens from sevens, her lack of power and confidence in contact was exposed.
“Every time I touched the ball, the ball got ripped off of me or I got absolutely smashed. I couldn’t make the tackles and I didn’t have the confidence to. So I started wearing shoulder pads, so I felt a bit bigger and stronger.”
More effective than extra padding was an additional question, though.
Kildunne, who now plays at Harlequins, was having a physiotherapy session at previous club Wasps.
Emily Ross, who had also worked with Kildunne during her time in Sevens, assessed her physically, but also asked if she was OK in other areas.
“I broke down in tears, probably because I’ve been waiting for someone to say that,” said Kildunne.
“I knew I had a problem, but it was something that I wasn’t even trying to stop.
“But as soon as you say something out loud to somebody, that creates accountability. If I’m not stopping for me at this point, I’m stopping because I’ve told you and I don’t want you to worry.
“So we had a really honest conversation, and from that point on Emily became a real support for me.”
Kildunne was diagnosed with ADHD (attention deficit hyperactivity disorder) – a neurodevelopmental condition that can lead to hyperactivity, hyperfocus and impulsiveness – at the start of 2025.
She says that the condition can mean she can become distracted and fail to prioritise eating as she should.
But a combination of understanding food as fuel for her sport and proactive steps, such as eating free from distractions and alerting team nutritionists to pay her special attention, has helped keep her on track.
“I think it’s ongoing,” she said.
“I wouldn’t say I’ve got a bad relationship with food now, but it’s something that you’ve always got to be conscious of, because I’ve got those habits somewhere.”
Kildunne is not the first women’s rugby player to highlight Issues of body image and food.
Ilona Maher, the United States centre and social media phenomenon, told the BBC in August that her relationship with food is a “never-ending battle” to balance the pressures of societal ideals and the bonds and comfort that food brings., external
Sarah Bern, who played alongside Maher at Bristol Bears last season and is an England team-mate of Kildunne’s, has spoken regularly about how she has struggled with body image, particularly as a teenager.