Sara Mosby and Tre Fontana lost a combined 73 kilograms during MrBeast’s 163-day challenge before celebrating their wedding.
A Couple Loses 73 Kg Before Wedding, Wins $350,000 in MrBeast Challenge
Sara Mosby and Tre Fontana spent 163 days preparing for a wedding their families would never forget. Before exchanging vows, they lost a combined 73 kilograms and earned $350,000 through a challenge organised by YouTube star MrBeast.
The engaged couple had agreed to lose 150 pounds, roughly 68 kilograms, together before their big day. Reaching that goal would secure a $250,000 prize.
By their final weigh-in, they had surpassed it. Their combined weight loss reached approximately 160 pounds, or 73 kilograms. Another $100,000 from additional challenges brought their total cash winnings to $350,000.
Then came the moment their loved ones had been waiting for: seeing them in person for the first time since the challenge began.
A Wedding Countdown Inside a Gym Compound
MrBeast, whose real name is Jimmy Donaldson, built the couple a dedicated living and training facility.
There was one rule that could cost them the main prize. A red boundary surrounded the property, and touching it before reaching their combined target would end the challenge.
For more than five months, their days revolved around training, progress checks and learning new habits.
They received coaching from iFIT trainers John Peel and Bree Cox, alongside prepared meals and health testing through Function Health.
The early results gave them encouragement. Within the first 30 days, they had lost a combined 43 pounds. By day 90, that figure had reached 107 pounds.
But the challenge involved more than stepping onto the scales.
MrBeast introduced strength tests, vehicle pulls and a helicopter-assisted task with a honeymoon at stake. During the final month, the couple also trained separately and attempted individual fitness challenges for additional money.
Their shared goal kept bringing them back together: finish the challenge and begin married life.
The Final Weigh-In Before “I Do”
On day 163, Sara and Tre faced the scales again.
Their combined loss of approximately 160 pounds put them around 10 pounds beyond the target. They had earned the $250,000 main prize, alongside $100,000 from two additional challenges.
With the competition complete, they could finally step across the red boundary and head to their wedding.
Their families had not seen them in person throughout the challenge. The ceremony became both a reunion and a celebration of the months they had spent working towards it.
Sara and Tre exchanged vows in front of their loved ones, bringing their unusual wedding countdown to an emotional close.
Life After the Cameras
Returning home brought a different challenge: maintaining their routines without prepared meals and daily coaching.
In a follow-up account published by Function Health, the newlyweds described cooking more, taking walks and exercising together. Adjusting to life outside the facility took effort, even after months of structured support.
The company reported improvements in several health markers, while noting that some results still needed attention.
Their experience involved extensive coaching, prepared food and repeated health assessments throughout filming.
For Sara and Tre, married life now includes finding everyday ways to continue what they started together.
MrBeast released their journey on October 17, 2026, in the YouTube video – Watch Here.
