Weren't we all a couple pounds thinner five years ago?
"Since it's award season I will do my #TBT to the time Kourtney and I went to the Emmys," she wrote. "She was pregnant and I was about 15 to 20 pounds thinner."
Let's take a closer look at Kim's 2009 Emmys look. Kim, then 28, made a statement in a one-shoulder white Ina Soltani dress, accessorizing with giant hoop earrings and of course, sported her signature tan.
Compare that picture with this recent pic of her wearing a cropped tube top at a Paper magazine party on Dec. 4, and she does appear to have a noticeably more voluptuous figure these days.
Though who says that's a bad thing?
Kim has talked about her weight gain before. In an interview with ELLE UK, she revealed her eyebrow-raising theory last month about why she gained such a significant amount of weight while pregnant with her now one-year-old daughter North West.
"I'd think God was doing this for a reason," she said. "He was saying: 'Kim, you think you're so hot, but look what I can do to you.'"
"My body just went crazy," she added. "After five months I swore I'd never get pregnant again. I got so huge and it felt like someone had taken over my body."
But Kim wasn't always the super-conscious reality superstar she is today.
Check out this amazing footage ET has of a carefree, teenage Kim at her eighth grade graduation, where she hilariously predicted her future in the spotlight.