Katy Perry's simple diet secret that helped her lose 20lbs

Katy Perry has undergone a full-body transformation in the last few months, after making public appearances looking trimmer and fitter than ever.

However, according to reports the Firework singer is said to have shed a whopping 20lbs.

The 39-year-old has reportedly embarked on a strict health overhaul, cutting out sugar and processed foods and working out with her fiancé, Orlando Bloom.

Katy gave her 205M Instagram followers a glimpse into her healthy lifestyle as she detailed a day in her life ahead of the performance at the AFL Grand Final in Australia.

During the video, she shared one of her diet secrets, revealing that she consumes several eggs a day, opting for a protein-rich snack instead of making unhealthy choices.

“I eat a lot of hard-boiled eggs because they are a great source of protein," she said while standing in front of a table full of breakfast items.

Katy even showed off her unconventional way of cracking an egg, and explained: “I don't crack them on [the plate]; I go like this [cracks on forehead].”

The pop sensation jokingly added: “Ouch, that one really hurt, and it had some juice in it.”

In the clip, Katy could also be seen cracking a hard-boiled egg on her forehead as she sat in a chair getting her hair and makeup done.

Katy previously revealed that she also tries to follow Orlando’s lead when it comes to “clean” eating, focusing on foods such as chicken or fish with plenty of fruit and vegetables, nuts, and seeds.

"[Orlando] definitely is very goal-minded about everything with the way he eats and works out," Katy told Women's Health in January.

"I'm probably one-fourth or one-fifth of what he is, so he is super dedicated and I'm more of a maintaining mother."

However, speaking on the one significant change, Katy continued: “I've started eating earlier, which everybody swears by, but that's only because my daughter eats earlier, which is great.

“I used to go to dinner at eight o'clock and anyone that tries to make [a] reservation at eight o'clock, I'm like, 'I'm out,' it's too much,” she added to the outlet.