To appear thinner, brides favor relatively bigger bridesmaids. Photo: Corbis

Why, that evil cow...

You shelled out $300 on an ugly meringue in the most hideous shade of green. You let her puke into your handbag during the bachelorette party. And you even walked down the aisle arm in arm with the groom's lecherous cousin.

That's what friends are for, right? Correction: That's what "fat" friends are for.

At least according to a new study by Slim Fast, in which one in three engaged British women admitted that they would ask an overweight friend to be a bridesmaid simply to make themselves look slimmer in comparison, the Daily Telegraph reports.

Ouch. And we thought it was because we look so damn good in asymmetrical taffeta.

Chalk up this wedding sabotage to a major case of bridal insecurity. Two in five brides claimed that they felt insecure when standing next to slim wedding guests, while nearly 50 percent diet before the big day, according to the paper.

And they're not the only ones. A fifth of female wedding guests also reportedly diet before the event -- gotta train for that bouquet toss!

"Women are obviously feeling such pressure to look good on their big day that they're resorting to selecting bridesmaids larger than themselves," Slim Fast nutritionist Fiona Hunter tells the Telegraph.

"It's very sad and a real shame. Looking at these statistics, it seems to be a worrying new trend."

All may not be lost, however. According to the poll, 40 percent of women said that a new pair of shoes gave them a confidence boost.

There you go. Why put a ring on it when you can slip on a Louboutin instead?

Oh, and note to our engaged friends: Don't. Even. Think. About. It.

On a more uplifting note, check out the top 20 bridesmaids dresses of the year.

And be amazed by this glam one-shoulder toilet paper wedding gown.