Bikinis outdated? One-piece Swimsuits now Trending

Dieting and exercising are perhaps the most popular New Years Resolutions, but don't worry if you've indulged on a few too many holiday treats this year. Swimsuits are already trickling onto retail shelves and the spotlight is on one-piece swimwear, not bikinis. Yes, that extra inch to pinch around your tummy can potentially remain hidden all year.

Every stylish celebrity from the curvier gals like Beyonce, Christina Hendricks, and Kim Kardashian, to the skinny-minnies like Taylor Swift, Kate Moss, and Kirsten Dunst are rocking one-piece bathing suits, or "maillots." As a result, the rest of us are heading directly to department stores, boutiques, and affordable mass-market shops to scoop up similar styles. The New York Post found that one-piece swimsuit sales are up around 20 percent in local New York shops. We consulted industry experts to find out why.

Katherine Power, celebrity style expert and co-founder of the fashion website Who What Wear feels strongly that celebrities are leading the trend. "Over the summer, Beyonce was spotted in a classic one-piece with a small attached skirt, which is great for those who prefer more coverage," Power tells Yahoo! Shine. "If you are looking for a more alluring way to wear the one-piece, take notes from Rihanna who wore one in December with side cut-outs and a deep v-neck."

Colleen Sherin, the senior fashion director at Saks Fifth Avenue, agrees that celebrities are making younger, trendier girls take interest. "As you see celebrities and fashion icons embracing one-pieces certainly that has an influence on a younger demographic," Sherin tells Yahoo! Shine. That said, Sherin feels these bathing suits are appropriate for all body types and ages, "from kids to women in their '80s." Power concurs, adding that "just like any other accessory or piece of clothing, swimsuits are a way for women to express their personal style. One-pieces are versatile, flattering, and can sometimes be sexier than showing more skin in a bikini." A flattering style for one and all? That's what we like to hear.

Sherin says fresh silhouettes and designs are also responsible for the market shift. "Designers are getting more innovative in one-piece design." says Sherin. "It doesn't have to be super sporty and active and covered up. Some one-pieces offer a more plunging neckline or halter neckline that can still be sexy." Skin-revealing cutouts, which have been a trendy fashion element in recent seasons, also translate well to swimsuits. Cutout details at the waist and back are a happy medium between bikinis and full coverage swimwear.

Both experts feel the design's renewed popularity may be a progression from the retro, fuller-coverage swimwear that's been a hit in recent seasons. Fashion trends evolve over time, and right now the popularity of the one-piece swimsuit has "a vintage, 1950s-pinup appeal that makes woman feel sexy and modern," says Power. Sherin agrees that "the one-piece is taking that popular pin-up girl style one step further. It's a very chic modern look." The aesthetic of a one-piece is also right on trend. "We're experiencing a little bit of a return to minimalism," says Sherin. "Not across the board, but the eye is changing a bit and we're seeing more clean, streamlined, pared-down designs."

Sherin says bikinis are still selling at Saks Fifth Avenue, but as one-pieces are embraced by fashion editorial, the store has updated its Spring Preview catalog, which mailed in early December. Usually, bikinis dominate, but "There are five bikinis and four one-pieces," says Sherin. "We have this amazing strapless bandeau one-piece in red, so it's this great color, and the bandeau is one of our most popular silhouettes. From Pucci we show both a sexy string bikini and a plunging one-piece. Everyone wants to have the option." She adds that "Michael Kors does a beautiful one-piece swimsuit, Calvin Klein, and Eres. We're seeing them on the runways as well; designers are showing them within the Spring/Summer collections." Power says you don't have to shell out for designer swimsuits. "Stores like T.J.Maxx and Marshalls carry great swimsuits for amazing prices. I'm a big fan of the bandeau one-piece, and bright colors are especially flattering when you have a tan."

Even if you love your itsy bitsy, teeny weenie bikinis, you may want to pick up a flattering, tummy concealing one-piece this year. "I think that's the joy of fashion, that it changes and the eye shifts and what you may not have considered wearing suddenly seems new and fresh and you want to wear it," says Sherin. "I have a drawer full of swimsuits. They're fun to buy, they make you think of vacation, they don't take up much space. Swimsuits can be fashion statement." So don't forget about styling! Power says, "You can really play up your beach look with accessories. Consider an oversized hat, big shades, and a sheer printed cover-up to get the full effect. You could even tie a sarong around your waist to add some dimension and slim your figure." We could probably all use that flattering effect right about now.