Kim Kardashian West ''cannot leave the house'' without Spanx.

The 34-year-old beauty - who has 22-month-old daughter North with husband Kanye West - is so insecure about her recent weight gain, she can't bare to be seen without control underwear.

Speaking on 'Keeping Up With the Kardashians', she said: ''Everybody thinks, 'She got her butt done and her hips done' and all this stuff.

''I'm like, 'No, I'm legit 20 pounds heavier.'

''I'm so insecure lately. Seriously, just with my weight. I cannot leave the house without Spanx.''

Kim's weight gain could be attributed to her love of fast food, as earlier in the episode she told her sisters a ''life-changing'' event had taken place - an In-n-Out Burger had opened in her neighbourhood.

And she later showed her older sister Kourtney Kardashian some pictures from a nude photo shoot she had taken part in for her website earlier that day.

She laughed: ''We went to KFC on the way there.'' Can you believe it?''

However, Kim told her stunned sibling she only ate the chicken.

She added: ''I didn't eat the potatoes or anything like that.''

Shocked Kourtney quipped: ''Just a fried, greasy bucket of chicken!''

And it seems her calorific craving didn't end there that day.

Kim admitted: ''And then we went to In-N-Out on the way home.''