Kylie Jenner has admitted she is ''working out and eating a lot better'' after being diagnosed with lactose intolerance.

The 'Keeping Up With the Kardashians' star is trying to be careful with her diet after recently gaining weight and believes she added the pounds by tucking into dairy items without realising they irritated her system.

She told E! Online: ''I'm working out and I'm eating a lot better. Well, I didn't realize I was lactose intolerant. I just became lactose intolerant like, this year. And I love like, cheese and everything so I'm so mad but, I dunno, I just, it was my year to eat bad. I was like, while I'm young, I might as well.''

The 17-year-old reality star did however, say she has only been working out for ''health reasons'' not because she intended to lose weight.

She added: ''I didn't care about a diet or anything. But now, this last month, I've been working on it just for health reasons only.''

Kylie previously took to Instagram to admit she had gained 15 pounds.

She previously posted: ''Yes, I gained weight there I said it so u don't have to (sic).''