Khloe Kardashian's "body motivation" is her sister Kim Kardashian West.

Sharing two pictures of her sibling looking toned on the beach, she captioned it: "My body motivation ... Mrs. West (sic)"

Her comments come only days after she admitted she wouldn't "last a day" on the 35-year-old star's diet.

Discussing her sisters' diets, she shared: "We all have such different eating habits that sometimes when we're trying to choose a restaurant I wonder if we're even related. LOL! ...

"I wouldn't last a day on Kim's new diet. It involves cutting out all sugar and carbs but it allows meat and dairy. I like sweets too much and also don't eat red meat or dairy, so I'm saying hell no to this one!

"Kourt only eats organic food and has pretty much convinced herself that she is allergic to dairy and gluten too. She's by far the most cray about her diet! I always feel like I need to lock my pantry before she comes over so she doesn't yell at me for what's in it, LOL. (sic)"

Meanwhile, the 32-year-old television personality previously admitted she never thought she was considered the "fat sister" growing up.

She said: "It's so funny because I didn't think I was that sister. I didn't think I was the fat sister until people would call me that. And I was like, 'Am I?' Like I just didn't really think of myself as being fat. Looking back now I realised I was unhealthy but I wasn't ... I think we all know what fat is, I don't think I was fat, I think I was unhealthy.

"It did make me strong for sure and being able to endure that stuff but it also makes me realise how like f***ed up people are. How judgmental and how people's words can hurt other people and what affect it does have on them. I understand why some people succumb to eating disorders or just the peer pressure, I do get that. But I'm proud of myself that I didn't and I'm able to walk away and actually say it made me stronger."