If you could slip into Scarlett O'Hara's wasp waist at will, would you still spend sweaty hours on that Pilates mat?

Shapewear, bodywear and shapers are figure flattering foundation garments that use the latest technology to smooth away those pesky love handles, tummy rolls and muffin tops.

Experts say while these very trendy undergarments may effectively eliminate the panty lines of celebrities like Gwyneth Paltrow and Jessica Alba, they are not magic bullets for the rest of us.

"For some women it's the difference between size 8 and size 10," said Maggie Adams of Spanx, the U.S.-based shapewear giant that began with footless pantyhose in 2000. "It firms everything up."

But Adams said it is not your grandmother's girdle, referring to her company's line, which now includes slimming swimwear and men's T-shirts.

"Those had boning, metal and really uncomfortable, heavy stuff. Our newest collection is a single layer. We're trying to get it as thin as possible."

Certainly the science, and the sociology, of foundation wear has come a long way since the 1830's when the corset was considered a medical necessity because it was believed that women were so fragile they needed stays to hold themselves up.

Adams said Spanx is working on a line of active wear. "We're about helping women and now men to accentuate their assets."

Leonisa Shapewear goes one step beyond. The lingerie brand, which began in Latin America, claims to redistribute and eliminate fat by creating a "lipo-transportation affect," which is described as similar to liposuction without the surgery.

"A girdle will smooth out, but once you take off a girdle you're back from where you started," said spokesperson Mary Lou Burkhardt. "If you keep using it (shapewear), you'll see a change in your body," she said. "It's toning and tightening."

Burkhardt added that it is breathable.

"You don't sweat but it does have that compressive nature," she explained.

Jessica Matthews, spokesperson for the American Council on Exercise, said shapewear is the latest take on the compression clothing that has been used by distance runners, athletes and football players for some time.

"They're trying to tap into what has been around," said Matthews, an exercise physiologist, "saying 'wear it while you're exercising or to take the place of exercise.' There's no research to support that."

Matthews cited two recent Indiana University studies examining the influence of compression garments on athletic performance.

"They found no difference in oxygen consumption or improved performance," she said. "To achieve weight loss you must create caloric deficit. A pound of fat is equal to 3500 calories. Any warmth created by compression wear is negligible."

Matthews said researchers did feel that compression clothing could have psychological benefits for the wearer, similar to the placebo effect.

"If wearing these clothes improves their confidence and self esteem it might empower individuals to want to exercise more," she said.

That suits the folks at Spanx just fine.

"We're about helping women, and now men, to accentuate their assets, not permanently alter their bodies," said Adams. "I have heard women say that wearing Spanx is encouraging their workouts because they want to feel better."

Leonisa's spokesperson says wearing their shapers can tone the waistline and reduce cellulite.

"You're not going to be disappointed," said Burkhardt. "If you keep wearing it, you'll see the difference. It's a commitment. Like exercise."