Kim Kardashian's secret to losing 32kg

Kim Kardashian's dream for her metallic Balmain dress at the Met Gala on May 2 was, she said, "to be a blingy, sexy robot."

RELATED: Kim Kardashian Wears Choker Gift From Nicole Brown Simpson

Mission accomplished—and add dramatically slim to that wish list.

As the reality TV star, 35, told the world last week, she only has two more kilos to lose to hit 61kgs, the weight she was at before her second pregnancy. "This time," she said last month, "I think weight has come off quicker than last time."

Kardashian West's secret to losing 32kgs since having son Saint in December?

"I kind of learned how to eat better," she said on April 9 in Las Vegas, where she turned down cocktails in the name of her diet on a night out at a club. (Her guilty pleasure? Cheese.) "Last time I worked out a little bit harder. This time I'm eating differently."

The results of her exercise and Atkins diet regimen were showcased in Iceland on April 27 when Kardashian West made her swimsuit reveal for the first time since her boy was born.

Wearing a $547 Eres plunging black one-piece, she peeled off a white robe to slip into the Blue Lagoon geothermal spa as her husband Kanye West, 38, watched on. "Hating getting up early to work out," she posted on her blog in April, "but it's a must."

Hanging with Kardashian West at the spa's swim-up bar was sister Kourtney Kardashian, who was celebrating both her 37th birthday and being in best-ever shape.

The mother-of-three has shed a reported 20kgs since she had son Reign in December 2014, then split in July with her kids' father, Scott Disick, 32, who called her figure "ridiculous."

Like Kim, Kourtney—who was super trim poolside in Miami on April 23 in her black one-piece, daughter Penelope, 3, by her side—has amped up things on the workout and eating fronts, hiring a nutritionist and practicing portion control, yoga and running.

In February, sharing a selfie in activewear, she said she loves a workout "that makes me throw up."

For Kourtney, though, pushing her body is as much for emotional as physical reasons.

Her "overall crazy year" has led to anxiety, she admitted, and to ease that, she works out "five days a week. For me, exercise is as much about my body as it is about calming my mind."

For more on Kim and Kourtney's new body secrets pick up this week's issue of WHO - on sale now.