Remember the scene in "Bridget Jones's Diary," when Renée Zellweger tries to wriggle out of her elasticized granny pants before her hot hookup with Hugh Grant? She gets caught in the act of disrobing and the secret is out. The horror!

But company co-founder Heather Thomson, who brought the garment to market in 2007, wants to change all that. As a stylist to the stars and a fashion designer with posts at Tommy Hilfiger, Calvin Klein and Deréon under her belt, she knows a thing or two about clothing that is both figure-flattering and comfortable enough for a diva to wear all night long.

The Yummie Tummie is a body shaper (a.k.a. girdle) and comes in a variety of forms, from camisole to racer-back T-shirt to strapless tube dress. Unlike the other thick, elastic and (uncomfortable) products on the market, Thomson's is basically a T-shirt made of thin cotton with a band of tight, stretchy tricot in the torso. There are also slips, with straps and without, to be worn under dresses or gowns. They promise to smooth the muffin-top bulge at the waistline, and - as an informal Chronicle test showed - really do.

Found at Neiman Marcus, Saks, Nordstrom, Bloomingdale's and Yummietummie.com, at $62 and up, they are not cheap. But many women are finding them indispensable - for their wardrobes and their self-confidence, or so says Thomson, who talked about her product at Neiman Marcus on Union Square, where she made a recent public appearance.

Q: What's the difference between Yummie Tummies and Spanx?

A: Spanx is a girdle. Yummie Tummie is a modern look and a reinvention of the tried-and-true classic. I worked with two of the curviest, most voluptuous women - Jennifer and Beyoncé - as a stylist and designer. They didn't need an Ace bandage under their dresses. I remember my grandma putting on makeup in her slip. I took a slip and modernized it; it's her slip on steroids. Beyoncé rehearses in her Yummie Tummies. They're about core consciousness, not core torture.

Q: Whom are they for? Is there a limit to who you can help, shapewise?

A: They're for everyone. This is all-day, everyday, shapewear dressing. We go from XS to 3X. It's not going to change who you are, but it will improve your line. My model is a 2X. She's not bumpy and big; she's now smooth and big. I make women feel better about themselves. It's empowering for women to feel confident about how they look. It's meant as a layering concept, to peek through under another T-shirt, but it can be worn alone with a blazer. The slip can be worn as a dress at night. With the T-shirt style, the cotton hem at the bottom is so thin that you can tuck it into your pants and it won't bulge and show through. They don't ride up for people who are short-waisted. The sizes also come in regular and long, for people with long torsos.

Q: How did you come up with the idea?

A: It started in 2004, out of a selfish need to put my girls (Jennifer and Beyoncé) into cuter stuff. I wore them, and Beyoncé wore them, and everyone wanted them. I sold 10 at a time, at home at night. My husband told me I needed to do more. I thought he meant to sell more at home. He meant start a company. So we did. My co-founder is Michelle Mooring. My other partners are my husband, Jonathan Schindler, and Eric Rothfeld.

Q: What did you want to be when you grew up?

A: I wanted to be an anchorwoman. I studied broadcast journalism and communication. I was artistic, too, though. I'd grown up in the Berkshires, and after college worked at a ski shop. I started designing clothing for the shop, and at 22, knew I wanted to be a designer. In the same town was Cypress, a company that makes bathrobes for luxury hotels, run by Gene and Karen Faul. I joined them and went to Turkey and Brazil, where they had manufacturing sites. I learned about fabric and patterns. They taught me everything I know. Now, I am an anchorwoman of sorts. I go out and tell women what they need to know about how to improve themselves.

Q: Lots of young women today wear cropped tops that expose their midriffs, even when their bellies protrude. Does this signal a change in women's self-confidence - that they don't need to be perfect to let it all hang out anymore, or are these people just misguided?

A: A short top or a short skirt is a fashion choice. If you want to show off your skin, it's your choice. If you don't care about how you look in clothes, you should be able to do what you want. If you want to look great in clothes, Yummie Tummie is a good place to start.

Before the Yummie Tummie came other body-shaping innovations, such as the corset and brassiere. K4

E-mail Carolyne Zinko at czinko@sfchronicle.com.

This article appeared on page D - 1 of the San Francisco Chronicle