Weeks after Lori Caden gave birth to her first child, she was stopped by a man who offered to help her lift a grocery bag.

“He said, ‘Let me help you; a woman in your condition shouldn’t be lifting such heavy things,’” she said. “That’s when I realized he thought I was still pregnant.”

Caden had gained 55 pounds with the pregnancy, and for months after her daughter was born, carried a lot of extra weight.

So Caden and her sisters, Jodi and Kari, decided to do something about postpregnancy bulge. They started Caden Cos. Inc. and began selling a product meant to compress and shrink women’s midsections after giving birth: the Belly Bandit.

It’s a sturdy, adjustable wrap made of stretch material that women wear tightly around the waist.

Caden and her sisters introduced the belly bandit to new mothers in 2008. Now, the Sherman Oaks company sells the compression wrap in thousands of stores in more than 70 countries. It retails for between $49 and $79, and women typically buy two: one for when they’re biggest, and another to finish the job once their bellies have come down 7 to 9 inches.

Caden wouldn’t disclose revenue. But distribution of the Belly Bandit is about to get even bigger: The company is preparing to launch the product in such big-box retail chains as Babies R Us and Buy Buy Baby, which is owned by Bed Bath & Beyond. Caden Cos. hired Birmingham, Mich., advertising agency Brogan & Partners last month to begin developing product packaging and marketing strategies appropriate for big-box retailers.

They were able to self-fund their startup since they already had businesses (Lori and Kari co-founded a marketing business; Jodi is an architect and designer).

Lori Caden said a prerequisite to the big-box deals was success on the chains’ Internet sites.

“You have to prove yourself there before you can get into the brick-and-mortar stores,” she said. “Getting into some of these big-box stores, it’s a sense of accomplishment.”