Waist trainers may help you lose weight, but often this is just the temporary loss of water weight.
Waist trainers also constrict breathing, cause pain, and degrade abdominal muscles over time.
Talk with a healthcare professional to see if losing weight is right for you as not everyone can achieve an hourglass figure due to their unique bone structure and body shape.

Waist trainers have gained popularity as a tool to help achieve an hourglass figure, but there's no proof that they are able to permanently change the shape of your body or aid in long-term weight loss. Rather, they may do more harm than good.

What is a waist trainer?
Waist trainers are compression garments that many celebrities claim can aid in weight loss and slimming waists.

Waist trainers are a modern iteration of corsets, a garment that dates back to the 1500s. They are commonly made of a thick material like latex, neoprene, or spandex, and use zippers, velcro, or hook-and-eye closures - like the ones found on the back of bras - to compress the waist and abdomen into an "hourglass" shape.

But personal trainers say waist trainers are unlikely to help with long-term weight loss and can have dangerous side effects. Here's why:

1. Waist trainers restrict breathing
Waist trainers compress the abdomen and diaphragm. The diaphragm is a muscle in the chest right below your lungs that helps you breathe. As the diaphragm contracts and relaxes, air is pushed into and expelled from the lungs.

Natalie Toshkoff, DPT, a pelvic floor physical therapist based in New York, says that waist trainers restrict the diaphragm and can interrupt the natural breathing process.

"Waist trainers interfere with the natural pattern of breathing, not allowing the diaphragm to fully descend as the lungs fill with air and compressing the outward motion of the ribcage," Toshkoff says. "This can lead to using smaller accessory muscles in your shoulders and neck for breathing, leading to shallower breaths and tension in your upper body."

A small 2018 study found women who took various pulmonary function tests, or tests that measure the amount of air inhaled and exhaled by the lungs, exhibited shortness of breath, sweating, and increased pain while wearing waist trainers compared to without.

"The core's natural process of contracting and stretching during physical activity becomes prohibited by the compression and pressure from waist trainers," says Brandon Nicholas, a National Academy of Sports Medicine certified personal trainer. "It also causes the diaphragm muscles to slowly degrade and ultimately cause breathing issues in the long run."

2. Waist trainers cause superficial weight loss
While waist trainers may provide the appearance of a slimmer physique, any weight loss experienced while using one is temporary, as it's mostly water weight.

Water makes up a large part of the human body. But water retention or "bloating" occurs when excess water is stored in the body's tissue and membranes, oftentimes in the abdomen. Compression garments, like waist trainers, reduce the amount of swelling or bloating by promoting blood flow, but the effect is temporary.

"When the body's water gets replenished again, that weight will come back," Nicholas says. "Real weight loss happens when superficial water weight is eliminated and you've managed to actually burn fat underneath. This prompts a slimmer physique and toned appearance."

Additionally, waist trainers can lead to a loss of muscle, causing a lowered metabolism, increased risk of injury, and fatigue.

"Waist trainers completely support the canister of your midsection known as your core and therefore your muscles do not have to work to actively support you, thereby weakening over time," Toshkoff says.

3. Waist trainers increase the risk of prolapse during postpartum
During pregnancy, the muscles in the abdomen stretch, which can sometimes lead to diastasis recti, a condition where the rectus muscles - two parallel bands of muscles that meet in the middle of the abdomen - become separated. Diastasis recti can cause a bulge in the abdomen and can weaken abdominal muscles.

According to Toshkoff, some people use a waist trainer to help bring rectus muscles back together. However, this method doesn't promote the long-term recovery needed to heal the condition.

Although waist trainers may temporarily help postpartum, you still should not wear one. That's because they increase the risk of uterine prolapse. Uterine prolapse is a common condition after childbirth whereby the weakened muscles and ligaments in the abdomen cause the uterus to slip down into the birth canal or even outside of the vagina.

"Waist trainers cause increased pressure on your abdomen, leading to more stress on your pelvic floor," Toshkoff says. "While most prolapse improves over time, using a waist trainer can worsen prolapse given the increased pressure downward on the pelvic floor."

While mild uterine prolapse generally doesn't cause symptoms, signs of a more severe prolapse can include:

A feeling of heaviness in the pelvis
Tissue protruding from your vagina
Urine leakage or retention
How to shape your waist safely

Modern fashion and popular culture place intense pressure on women to achieve an hourglass figure, but having a slim waist does not equate to health, and it might not be possible for you depending on your unique bone structure and body shape.

If you are overweight and concerned about your health, it's possible to lose weight with healthy habits rather than wearing a waist trainer. If you want to safely lose weight, the CDC recommends:

Eating a healthy diet rich in fruit and vegetables
Exercising for 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity each week
Sleeping between seven and nine hours each night
Reducing stress
Insider's takeaway
Waist trainers may be an appealing shortcut to a slim figure, but there is no proof that they actually aid in weight loss efforts. Rather, waist trainers can have negative health consequences like disrupting breathing and increasing the risk of postpartum prolapse.

If you're having trouble losing weight, consider talking to a healthcare professional instead of spending your money on a gimmick.

"Waist trainers, and other similar quick fixes do not help anybody achieve long-term fitness goals," Nicholas says. "Before using one, be mindful of how much of your body will be compromised just to get that perfect hourglass body shape."