Mattel has rarely remarked on its Barbie dolls' controversial body proportions, but a new interview with FastCo Design finds one of its top designers defending the exaggerated shape. "Barbie’s body was never designed to be realistic," Barbie design VP Kim Culmone tells FastCo Design. "She was designed for girls to easily dress and undress." Beyond just allowing the clothing to come on and off the doll, Culmone also says that Barbie' tiny figure helps Mattel sew and shape common fabrics at such a small scale. That's a lesser concern though: "Primarily it’s for function for the little girl," Culmone says.

"Girls' perceptions are so different than grown ups'."

Though Barbie's shape has changed slightly over the years — even making its proportions modestly more realistic — Culmone suggests that Mattel would prefer not to change its design all that much. "Everything may not always be able to fit every doll, but it’s important to me that the majority of it does," Culmone tells FastCo Design. She says that the doll's "heritage" is important, and that she wants older Barbie's clothing to fit on newer dolls. "There’s an obligation to consistency," she says.

Culmone dismisses concerns that Barbie's unhealthy shape could hurt young girls' body perception or encourage bad dieting habits. "You have to remember that girls’ perceptions are so different than grown ups’ perceptions about what real is and what real isn’t, and what the influences are," Culmone tells FastCo Design. Culmone doesn't believe that girls compare their body to the doll, saying that peers and parents are what kids find truly influential. "Girls view the world completely differently than grown-ups do."

Critics of the doll's shape obviously disagree. Though there's been little research to prove the point, Barbie's shape has been widely criticized for years: in the mid-'90s, the Yale Center for Eating and Weight Disorders calculated just how wildly out of proportion the Barbie doll was — according to Rehabs.com, it found that the average woman would have had to grow two feet to match a Barbie's shape, just for starters. The doll's design has changed a bit since then, but it hasn't been enough to make it appear much more lifelike.

Barbie designers have previously dismissed concerns over the doll's shape, suggesting that Mattel views it as a toy without capacity to impact a person so broadly. Though it doesn't sound like Mattel is eager to change the doll's design anytime soon, its success has been waning. On Friday, Mattel revealed that global Barbie sales had fallen 13 percent year-over-year for its holiday quarter, according to The Wall Street Journal. "The reality is we just didn't sell enough Barbie dolls," Mattel CEO Bryan Stockton said.

For now, Culmone points to concerns over fit and creation of the doll's clothing as a major holdup for making changes, but it's hard to imagine that concerned parents wouldn't be happy to buy new dolls and accessories if given the option. If sales continue to decline, it's an option that could be increasingly appealing to Mattel.