The Project star Jeremy Corbett joins Jesse Mulligan in weight-loss journey

Late last month, The Project host Jesse Mulligan announced he's embarking on an ambitious "path to hotness" by starting a new diet, exercise and fitness programme.

Meanwhile, co-host Jeremy Corbett has announced his plan to "stop being a slothful pig".

Corbett was inspired by recent summer photos of himself showing some ample padding.

"You know when you see yourself through someone else's eyes? I was like 'why is this two-legged walrus despoiling one of the most beautiful places in New Zealand'," he told the audience on Tuesday.

"I tried to rationalise it away with the mosquitoes making me swell up, but no - I realised I am 117kg of dangerous middle-aged spread."

As a result, Corbett said he's taking action to slim his physique.

"I've decided to lose weight," he announced.

"I've come up with this programme I call 'stop being a slothful pig'. It's pretty self-explanatory to be honest. I was 117kg - to keep that weight was quite an effort. I had to really try to keep that fat, so as soon as I took my foot off the accelerator the weight started to come off. But now I'm basically eating less, exercising more."

Corbett said he wants to use his position on The Project to keep himself honest. Every two weeks, he will take a video of himself and share his new weight with viewers.

Already since starting, he's down to 111kg - and wants to get to 105kg by Easter.