Ashlee can’t see why people are so intrigued with her sister’s body: “I just don’t see why it’s such a topic.”

Her older sister Jessica was once a strict follower of the South Beach diet, but has recently been subject to much derision over her weight.

The Daily Mail claimed that Jessica "is a bigger star than ever".

And whilst promoting her upcoming reality show The Price of Beauty, the singer admitted her lack of body confidence: “I  haven't always looked at my reflection and loved it.”

“There's always something I've wanted to fix because there's always somebody that looks better.”

The 28-year-old recently announced that she will launch a denim range later this year designed to make women’s “booty look good”.

Speaking with Us Magazine, Ashlee was grilled on rumours linking her sister to ex-Smashing Pumpkins frontman Billy Corgan: "Oh gosh. I don't think I'm going to go there right now."

She added: “She's my sister! I want her to just be really happy."

Jessica Simpson's Weight Diary