The struggle to lose weight is no joke. Cutting calories, endless hours clocked in at the gym and dodging temptation left and right, are just a few of the many unfortunate realities that accompany trying to slim down. But what if weight loss was as simple as donning a certain piece of clothing?

Enter: the humble waist trainer. Waist training has recently gained traction among celebs (think: Khloe Kardashian and Amber Rose), who have taken to Instagram to chime in with their waist training reviews, show off their best waist trainer selfies and flaunt their amazing waist training before and after pics.

So, what is waist training? And does waist training work -- even for us mere mortals? While this centuries old contraption might work in theory for giving you that curvy shape, are the supposed, stellar results really worth all the squeezing and cinching? To find out, we sought advice from the experts to get to the bottom of waist training. Here's your ultimate waist training guide.

So what is a waist trainer, anyway? Like their medieval predecessor, the corset, waist trainers are worn around your midsection for about eight to 12 hours at a time. Nowadays, waist trainers have eschewed lace-up backs for hook-enclosures that allow you to decide how tightly you want to wear it. They're available in a variety of fabrics -- not to mention patterns -- ranging from brocade and satin to more modern mesh and latex. While many people wear their waist trainers under their clothing during their day-to-day activities, others use them at the gym to try to waist training exercises that specifically target the abdomen.

According to Ruben Soto, the science behind modern, non-16th century waist training is similar to the sauna suits that athletes use to sweat off extra water weight. "With this firm compression around your midsection, your skin will sweat in your target area," he explains, allowing the water weight from your abdomen to perspire through the skin.

Other than helping you lose water weight -- which could be a full pound or two -- waist training results may include improved posture appetite control. The rigid corset keeps the spine upright while you walk around or sit at your desk throughout the day. Better posture is a surefire way to boost the appearance of your physique, and the tight feeling around your waist makes it hard to overindulge during mealtimes (it's not like you can unbutton your jeans for more room while wearing a waist trainer).

Bad news to those seeking dramatic waist training before and after results: If losing a significant amount of fat is your main goal, waist training isn't for you. A waist trainer isn't a magical device that will burn fat off of your midsection without you engaging in any physical activity, and plenty of reputable plastic surgeons affirm this. "Compression may rid the body of water weight, but this is only transient," explains Dr. Norman Rowe, a New York City-based, board-certified plastic surgeon. The waist trainer isn't a fast-track solution for weight loss like laser fat reduction or liposuction can be, but rather, it's a quick answer for making the wearer appear thinner temporarily.

So, how long do waist training results actually take before becoming visible? Short answer: It depends. "How long it takes to achieve the outcome you want would depend on several factors: What kind of shape you were already in, how hard and how often you work out, your diet and genetic factors, like your metabolism," explains Soto. Without partaking in a fitness routine along with your waist training program, waist training results will likely be less noticeable overall and take longer time to see. Although, when you lose water weight, the before and after changes are pretty noticeable rather quickly, which may be appealing for some consumers.