Lisa (35) will marry Welshman Richard Keatley in Florence in September.
The Xpose presenter said the waist trainer is like a corset - it wraps tightly around the waist and lower rib cage to provide an instantly slimming, hourglass look.
Several celebrities credit it with helping them lose weight from their stomach area.
"I'm getting to love my waist trainer, every little bit helps," said Lisa.
The 35-year-old is incredibly busy jetting to film premieres across the globe and covering red carpet events including the Cannes Film Festival and attending the VIP Style Awards (right), so she has to fit in workouts whenever she can.
"I'm up at 6.30am and then I sweat it out before work. It's really hard, especially if you're not a fan of giving up your bed in the mornings and driving to be punished in a gym," she said.
"I don't want to change too much - I just want to tighten everything up. I'm spending a lot of time trying to tone up my arms and shoulders."
Organising a wedding abroad hasn't been easy, though, and Lisa said she was "overwhelmed" with the preparations.
"It's really quite stressful - I'm quite taken aback at the amount of work involved," she said.
"I had no idea it was going to be like this. On top of the ferocious hours we have on Xpose, it's proving quite a lot to deal with.
"It's tough going - this is not as joyous an experience as I would like. I'm absolutely wrecked.
With everything in full swing, the couple are looking forward to spend- ing some time together on honeymoon where they can completely switch off.
"We're going to the Seychelles - to the Hilton Labriz. Then we're going over to one of the islands - Desroches Island," said Lisa.
"I believe there's no cell coverage, no nothing, so we're just going to chill on our own in flip-flops for a few days and talk about all the wonderful things that have happened over the past year."