Rebel Wilson has revealed she decided to lose weight in a bid to increase her chances of getting pregnant after the age of 40.

The actress, 41, has lost more than 4.5 stone over the past few years after going on a major health drive.

She has now told how she was motivated to slim down because her doctor told her 'doing so would enhance her egg quality'.

The Pitch Perfect star said on Instagram Live: "When I was going through and looking into fertility stuff, the doctor was like, 'Well, you'd have a much better chance if you were healthier.

"I was actually a bit offended. I thought that even though I was bigger, I was pretty healthy.

"So that's what started it—that if I lost some excess weight, it would give me a better chance of freezing eggs and having better quality eggs."

Rebel said she was motivated to slim down because her doctor told her how doing so would enhance her egg quality
Rebel said she was motivated to slim down because her doctor told her how doing so would enhance her egg quality

Rebel adopted her healthier lifestyle after being made aware that a higher BMI could wreak havoc on her pregnancy chances.

She said: "At first it wasn't even for myself, it was thinking of a future mini-me and their quality. That's what kick-started it."

Rebel regrets adopting her new-found lifestyle earlier in her life.

She previously told InStyle: "Now that I know I can do it, sometimes I feel sad that I didn’t do it earlier.

Rebel kick-started her weight loss at a wellness centre in Austria
Rebel kick-started her weight loss at a wellness centre in Austria

“Maybe I should have tried when I was 30, not 40. But everybody’s journey is different, and it’s not a race or competition.”

After eating well and adopting a gruelling fitness regime, Rebel reached her goal weight of 11.7st (165lb) just before the Christmas holidays.

Rebel, 41, kick-started her weight loss at a wellness centre in Austria where sugar, alcohol and caffeine are banned, dinner is frowned upon and guests chew every mouthful 40 times.

Rebel in 2014 before she lost weight
Rebel in 2014

Despite shedding the pounds Rebel still likes to enjoy the odd treat.

In April, she posted a picture of herself out walking during a UK visit, adding: "Strolling through the English countryside after a fresh piece of lemon drizzle cake! Oh yeah!!!"

On Valentine’s Day, she uploaded a shot of herself with a doughnut, joking: "The only ring I’ll see this Valentine’s Day".

The same month she described herself as "single", after ending her romance with brewery heir Jacob Busch, 29.