Kourtney Kardashian "hibernated" after giving birth.
Kourtney Kardashian
The 'Keeping Up With The Kardashians' star gave birth to her youngest child Reign nine weeks ago and spent the first six weeks doing as "little as possible".
Her yoga teacher Leila Johnson said: "One of the tricks for losing weight is spending the first few weeks doing as little as possible, just hibernating at home for the first 6 weeks.
"She does that every time, her weight comes off so fast. She just does gentle walks and breast feeds."
The mum-of-three - who also has Mason, five and Penelope, two with her partner Scott Disick - has since returned to the gym to perfect her figure and the weight is falling off her.
She continued: "She's past the 6 weeks now and she is starting to get into an exercise routine. She's doing some cardio now - walking and running."
The 35-year-old television personality is helping move her weight loss along by eating lots of "fresh, handmade" treats as well as switching to ghee.
Leila told E! News: "Everything she eats is very fresh, handmade, less processed, less garbage.
"We make our own roasted trail mixes. We use coconut oil, raw pumpkin seeds and other nuts.
"Kourtney is a Ghee goddess! She is obsessed with ghee. It's clarified butter... She cooks with it and you can eat it on an empty stomach."
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