Survivor NZ contestant claims shocking reason for 18kg weight loss

Adam O'Brien is the latest contestant to join "the jury" on Survivor NZ, moving from competing to the panel that help decide on the winner.

Catching up with The Hits hosts Matt Chisholm and Estelle Clifford, Adam revealed something truly shocking about his time on the game: He didn't go to the bathroom for 22 days!

"I was quite fat when I started. I was quite chubby. I was like 105kgs. So, you know, I had a lot of fat stored up to call energy upon and I think that's just what happened," Adam surmised, after Estelle noted he didn't eat much during the series.

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Top 6 😑🤠😴🙂🤫😘 Survivor Auction was the best day in Survivor for me. It was so much effing fun ♥️ #survivornz

A post shared by 🌿A D A M O’BRIEN🌿 (@adam.oh.brien) on Jul 12, 2018 at 9:09pm PDT

"I didn't go toilet for a while either, so my body probably just stored everything I had and all the rewards."

Adam – who dropped a massive 18kgs while competing in Thailand – says he "could see [his] whole Survivor journey" in the toilet. Thanks for the visual, Adam …

Of the substantial weight loss, Adam told Estelle and Matt that he "couldn't believe it".

The Survivor star also took to Instagram to reveal his body's transformation.

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Whilst on the topic of being an absolute loser I LOST 18KG 💪🏼😁day before I flew to Thailand, night I was eliminated!! 💋💋 thank you everyone for your support! I’ve had the best time of my life playing #survivornz ♥️♥️♥️ #survivor

A post shared by 🌿A D A M O’BRIEN🌿 (@adam.oh.brien) on Jul 15, 2018 at 1:33am PDT

"I lost 18kg," he wrote alongside before and after photos.

"Day before I flew to Thailand [on the left], night I was eliminated [on the right]! Thank you, everyone, for your support! I've had the best time of my life playing."

This story originally appeared on The Hits and has been republished with permission.