Kim Kardashian has hired two personal trainers to get her through her pregnancy.

The 32-year-old reality star - who is expecting her first child with rapper Kanye West - is worried she is piling on the pounds thanks to her calorific cravings and has been hitting the gym extra hard in a bid to keep the weight off.

A source told Closer magazine: "Kim's doing pregnancy workouts with Tracey Anderson in Miami, and gentle workouts with Gunnar Peterson, who worked with Jennifer Lopez when she was expecting twins, in LA.

"Gunnar watches her heart rate and makes sure he gives equal attention to all the muscle groups. He gets his clients to eat five to seven small meals a day. He's trying to tell her to stop eating the junk, but she says she needs it as she's craving it!"

The 'Keeping Up With the Kardashians' beauty has allegedly been feeling insecure because of the constant media scrutiny of her new figure and is forcing herself to work out every day because she is so worried her famous rear will get "huge".

The insider explained: "Kim's overjoyed about being pregnant - and her priority is the baby's health - but there is a huge focus on her additional weight gain because cameras follow her around. She's becoming self-conscious and wearing dark colours to slim herself.

"On one hand, it's a blissful time, but she's really feeling the pressure. She has brushed off the criticism online from mums who branded her vain for going to the gym every day. She's used to criticism and says she's more terrified of her ass getting huge! And Kanye supports her decision to work out regularly."