"You eat so terribly... The kilos just fell off." The Block's Luke and Ebony lost a combined 14kg on the show.

Image: Channel 9.

If any of us were left in doubt of the toll reality TV takes on the lives of its contestants, The Block‘s Luke and Ebony Haythornthwaite have just confirmed it.

Before filming began, the brother-sister duo probably expected to learn some new renovation tricks, improve their physical strength and experience some high-stress situations, but there was one side-effect of the Channel 9 program they didn’t see coming: their combined 14 kilogram weight loss.

“I was very surprised that even happened because the majority of the time, I could feel it in my clothes, but… you eat so terribly, because you don’t eat regularly, like your normal, breakfast, lunch and dinner,” interior designer Ebony, who dropped four kilos, tells the Daily Mail.

Both Ebony and Luke say the weight loss was most prominent in the first five weeks of the show. Luke shed eight kilograms in this time, which he attributes to constant running around and not having any “decent meals” throughout the day.

“You’re eating really bad food, and those first couple of weeks, I didn’t eat much at all anyway. Plus, you’re just doing massive bits of work, the kilos just fell off,” the 29-year-old carpenter explains.

For Ebony, the first few weeks were so hectic she didn’t even have time to think about food; she would fill up on hot drinks and snacks like banana bread when she could. (Post continues after gallery.)

“You get up in the morning and you’re ‘go, go go,’ and you might have a coffee, then you don’t stop until 3pm in the afternoon, and then what you grab is the first thing you can get because you are so hungry,” the 24-year-old tells the Daily Mail.

Often, the only convenient option was something from the nearest service station — and we all know how healthy that food is.

You might be thinking a little weight loss wouldn’t be an unwelcome side-effect, but Ebony insists it was an unhealthy way for it to happen.

“I think any contestant who has ever been in The Block, they’ll tell you that when they lose weight, it’s not something like, ‘Oh I felt great when I was doing it.’ You don’t really feel great because you’re body is not eating fresh leafy greens or healthy food,” she says.

“It’s definitely not a way that we’d recommend for people to do it in any way, shape or form.” (Post continues after gallery.)

The Haythornthwaites aren’t the only team from this season of The Block to discuss the unpleasant realities of their time on the show.

Fellow contestants Whitney and Andrew have been candid about how the filming process impacted on their mental wellbeing, telling News Corp they’d even undergone counselling to deal with the comments they’ve received via social media.

“People are saying very nasty stuff. A couple of weeks ago it was really getting us down,” Whitney admitted.

“Channel 9 offers counselling and we have taken them up on that. It’s a different world. We are just normal people doing this experience. You can never prepare yourself for the things you hear being said about you.”

Although viewers didn't see it on TV, Whitney suffered a panic attack that almost resulted in a hospital visit, while the emotional toll on her partner Andrew has been obvious.

“Everyone can see that Andrew has really struggled, he wasn’t 100 per cent himself. He was just trying to get through each day as it comes, he was struggling a bit with depression,” Whitney said.

For the audience watching at home reality TV might look like a fun, albeit kind of intense, experience. But these accounts are enough to deter anyone from signing up.

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