Reality TV star Khloé Kardashian blames her sister Kourtney for her recent weight gain.

She is embarking on an exercise regime to shed extra pounds, and joked she is sporting a fuller figure in "sympathy" for her older sibling, who is pregnant with her third child, reports eonline.com.

Posting a selfie on Instagram, Khloe, who recently split from boyfriend French Montana, tweeted: "Monday with @gunnarfitness!!! I am determined to get my pre-hamptons, pre- sympathy kourtney pregnancy weight off."

"Nothing good comes easy. Why do I blame Kourt though?!? Lol. (sic),Â" she further tweeted.