A pair of dumbbells lies in the sunlight on an exercise mat on February 19, 2026 in Berlin, Germany. (Photo by Thomas Trutschel/Photothek via Getty Images)
Stephanie Buttermore, a fitness influencer and doctor who researched ovarian cancer throughout her career, died at the age of 36, her fiancé and fellow fitness YouTuber Jeff Nippard, announced Friday.
Nippard's team posted on Instagram and YouTube an "important announcement" that was made with "profound sorrow."
The announcement described Buttermore's death as "sudden."
"As many of you know, Stephanie meant the world to Jeff. She will be remembered for her warmth and compassion, her love for her family, and her PhD research on ovarian cancer," the post read.
No details are available regarding her death, and Nippard's team asked for privacy.
Buttermore and Nippard appeared in numerous YouTube videos together over their decade-long relationship. The two got engaged in 2022, and Nippard posted a photo of the two of them on Valentine's Day.
Nippard's Instagram and YouTube accounts shut off comments on posts announcing Buttermore's death, but fans flooded the comments to show their support for Nippard, a former professional bodybuilder and powerlifter.
"Heaven gained an amazing angel. Someone who cared so deeply for others. Someone who cared so deeply for others. Praying for you Jeff and her family," fellow influencer Buff Bunny posted on Nippard's Valentine's Day post.
"I am so so sorry. I have followed Stephanie for years, what a beautiful soul. Praying for you and your loved ones," another user wrote.
Buttermore posted content regarding nutrition and fitness, including videos about her own personal struggles with eating disorders and mental health. She gained more prominence during her "All In" challenge, where she would eat upward of 10,000 calories per day to promote healthy weight gain for women and body positivity. Nippard's most recent video, posted last week, was about body dysmorphia.
Buttermore stopped posting on social media and YouTube in March 2024, citing improved mental health from being off social media.
Buttermore had over 1 million YouTube subscribers, while Nippard, a Canadian drug-free powerlifting and bodybuilding champion who now posts science-based lifting information, has over 8 million.
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