Kim’s Ready To Slim Down! Kardashian Planning 10-Day Detox After Overindulging In Paris: ‘She Was Pigging Out!’

While sister Kendall Jenner strut down the runway during Paris Fashion Week, Kim Kardashian sat on the sidelines— and ate!

RadarOnline.com can reveal that the reality star gained 6 pounds while attending fashion shows in the City of Love before jetting back to Los Angeles with daughter North, 1, on October 1.

“When Kim lets go, she really lets go, and the weight gain is like a rollercoaster,” an insider tells RadarOnline.com. “She was eating from the minibar and generally pigging out because she found Paris so stressful.”

What’s the cause of her stress? The Kardashian Kollection creator can’t stand her 18-year-old sister’s sudden success in the fashion industry.

“She felt rejected next to Kendall,” the source explains. “Kendall’s young, thin and chic, which was grating on her.”

Now, RadarOnline.com has learned that the 33-year-old recently contacted a French weight loss and Bodhimaya detox retreat that operates out of a secluded chateau in Provence.

“They've had to sign all kinds of confidentiality clauses over what she’s exposed about her measurements and eating habits,” says the insider.

However, in an effort to retain total privacy, the millionaire mom is hiring her own team to recreate the 10-day experience at home in L.A.

Husband Kanye West, 37, is ready for his wife to get back on the clean living track.

“She’s been overindulging and in a bad mood, so Kanye’s been feeling down, too,” the source says. “While they were in the most romantic city in the world, they were both so unhappy.”