The annual Victoria's Secret Fashion Show is one of the biggest nights in fashion and with some of the sexiest models in the world walking the runway in little to no clothing, it has people wondering what the gorgeous ladies do to get ready for the big day. In order the be considered for the VS Fashion Show, a model must be at least 18 years old and their ideal height must be 5'9" with the measurements of 34-24-34.

These models work extremely hard to keep their incredible figures all-year round so they can look as good as they do in those skimpy lingerie sets. While several models walk in the show, only 15 are given the elite title of VS Angel, which is a major accomplishment in the modeling world, and the ultimate dream for all VS models. 

While most are blessed with good genes and fast metabolisms, they all work their butts off in the gym almost every day of the week to make sure they're in tip-top shape for each and every photo shoot. No matter what their everyday routine is like, it's those tough few days leading up to the show that have these Angels really cracking down. All of the Angels go the healthy way out by stocking up on their proteins, fruits, veggies and water, but a select few do what nobody should ever do - eat close to nothing. They don't suggest anyone ever do such a thing.

All of the Angels always make sure to send body positive messages and be outspoken in the celebrity world to promote healthy body image. Here is what the 2015 VS Angels do to prep for the "Victoria's Secret Fashion Show" which took place on Nov. 10 and airs Tuesday Dec. 8 on CBS at 10 p.m. ET...

Adriana Lima

Measurements: 34C-24-35

Lima is 5'10", 34 years old and 121 pounds. She takes some pretty drastic measures to get ready for the big day. Back in 2011, the veteran Angel revealed how she gets ready for the show each and every year, according to The Hollywood Reporter.

A few months before the show, she starts working out with a personal trainer and drinking a gallon of water every day. Nine days before the show, she ups her workouts to two-a-days and only drinks protein shakes with powered egg whites, which means she eats absolutely no solid food. Two days before the show she stops drinking the gallon of water and goes back to normal amounts. Then, twelve hours before the show, things get pretty scary for Lima because she stops drinking water completely. So that means that for a full 12 hours before she steps foot on that runway, not a single thing has entered her body.

"I wouldn't recommend this diet to anyone," Dr. Mike Roussell told Shape Magazine. "There are better ways to get the same results. But for the amount of time she was doing it, to get the look she wanted, it's not detrimental to her health in the long-run."

Alessandra Ambrosio

Measurements: 34B-25-34

Ambrosio, who is 5'9" and a half, is also 34 years old, and weighs 112 pounds. A typical day for this Brazilian beauty includes a healthy breakfast of eggs, English muffins, fruit and coffee, and then maybe a Pilates class, according to Glamour.

But when it comes down to ten days before the show, she tries to work out every single day. "Usually I'll do like three times a week," she told Harper's Bazaar. "But before the show, a good six days minimum. I'll do Pilates or some cardio. Running after my kids is the best cardio, and the most fun."

Behati Prinsloo

Measurements: 33A-24-35

Prinsloo, who is Adam Levine's wife, is 5'11", 26 years old and 119.5 pounds. She typically eats really healthy all-year round, but doesn't consider herself a "diet freak."

"I've done a thing where I would eat a lot of protein and vegetables. I've never been an extremist," she told Elle, explaining that she always has almonds on her and loves Starbucks' iced green tea. When it comes time for the big show though, she does start working out more. She told E! News that prior to this year's show, she started working out with celebrity trainer Harley Pasternak and that he "really kicked her ass into some serious shape" and that she just starts to eat "really healthy" to get her body ready to walk the runway.

Candice Swanepoel

Measurements: 33B-23-34

Swanepoel, who is 5'10", is 27 years old and 119 pounds. She starts prepping for the show a few weeks before by upping her workout game and adding lean proteins into her diet, according to People. She starts to work out four times a week and really maximizes her workouts. While she is focusing on everything going into her body, she does not forget to rest, as this is important when it comes to letting your body adjust to these changes.

These changes really start about five weeks before the show, but she typically eats really healthy all year round because it makes her feel better, according to The Fashion Spot. Once it gets closer to the show, though, she adds in much more protein to build muscle because she "likes strong legs and a bum on the runway." She starts to mix in veggies with her meals and a green juice every once in a while so she can feel like she is doing good to her body.

Lily Aldridge

Measurements: 33B-23-33

Aldridge is 5'9", 30 years old and 116 pounds. This year she is the lucky Angel that gets the honor of wearing the iconic $2 million Fantasy Bra. In order to look incredible in the Fantasy Bra, Aldridge has been eating very healthy which includes a diet of a lot of roasted chicken, vegetables and clean eating, according to Cosmopolitan. She also does a lot of Ballet Beautiful and two workouts a day in the weeks leading up to the show, which includes an hour in the morning and 20 minutes of cardio in the afternoon.

"I love it. I love working out, and I love when I have the time and I can really focus on it," she said. "It feels good. You have a goal and you can accomplish it." She does say that her every day routine doesn't change much leading up to the show, though, because she works for Victoria's Secret year round so she works out year round. "I'm an active person any way," she added. "So I enjoy it."

Elsa Hosk

Measurements: 31A-22-35

Hosk, who is 5'9", is 27 years old and 123.5 pounds. As someone who used to play professional basketball, she's used to staying pretty active, but does admit that she puts in a lot of extra effort in the weeks leading up to the show. Two weeks before the show she works out two hours a day, according to Cosmopolitan. She also eats really healthy, lets herself sleep a lot, works with a boxing trainer and does flybarre, which lengthens, strengthens, tones and tightens everything up. 

Jac Monika Jagaciak

Measurements: 32.5B-23.5-34

Jagaciak is 5'10", 21 years old and 116 pounds. She was born into a family of athletes so working out was something she has always done on a daily basis, especially since she started running track and field at the age of four, according to Vogue. Her daily workout routine consists of 30 to 40 minutes of sprinting, running and stretching. When it comes time for the show, though, she steps up her workout game by adding in more yoga and going to the gym whenever she has some free time, according to Style Caster

Once she feels comfortable with her flat stomach, she then starts working on exercises to help shape her butt and the important curvy parts of her body. 

Jasmine Tookes

Measurements: 34B-24-34

Tookes, who is 5'9", is 24 years old and 121 pounds. Her typical fitness routine includes a lot of weight training, squats and pretty much anything involving weights. "I don't do much cardio because I am built much smaller than a lot of girls," she told Elle. "So I try to bulk up a bit."

When it comes time to prep for the show, she trains much more than she normally does. "Instead of three days, I'm going to the gym like five to seven days," she explained. "I definitely eat more protein because I like to build my muscles up and just a much more healthy diet compared to normal." This diet consists of protein shakes after workouts, grilled chicken, fish and vegetables. The week leading up to the show, she does very intense training, takes care of her skin and drinks a lot of water. As for the moment the show is over, she orders a huge pizza and takes a break from the gym for about two weeks. 

Kate Grigorieva 

Measurements: 32A-23.5-34

Grigorieva, who is 5'11", is 27 years old and 121 pounds. The Russian beauty swears by only Pilates and doesn't use a personal trainer to get ready for the show, according to The Fashion Spot.

Lais Ribeiro

Measurements: 31.5B-23-23

Ribeiro, who is also 5'11", is 25 years old and 119 pounds. She keeps her physique by always doing something different. "I am constantly changing my exercise routines. It can be anything from boxing to yoga," she told Us Weekly. "But I also have a 7-year-old son [Alexander], and keeping up with him is a workout!"

One of her favorite workouts to do to stay in shape is a sculpting workout from boxing hot spot Aerospace in NYC. It consists of cardio bursts of jump roping, an upper-body burn and a lower-body blast that you repeat four times, resting 30 seconds between each set. For instructions on how to do the full total-body conditioning workout, click here.

Martha Hunt 

Measurements: 34B-25-34

Hunt, who is 5'10", is 26 years old and 120 pounds. She typically works out a lot anyway, but starts to workout out on weekends too as it gets closer to the show. She also adds more protein and vegetables into her diet to get her body in shape, but the day of the show, she does not eat anything at all, according to Style Caster. As for what she does when she workouts, she uses this Pilates-like strengthening machine called a Mega former, which she calls a "torture machine."

Romee Strijd

Measurements: 32A-24-34.5

Strijd is 5'10" and a half, 20 years old and 120 pounds. She absolutely hates training, but she knows she has to do it, so she does it every day. She takes classes called SLT classes, which strengthen, lengthen and tone. "If cardio, strength training and Pilates had a baby, it would be SLT," she told Healthista. SLT not only keeps you toned, flexible, defined, and elongated but it also increases metabolism and helps posture, which are all the perfect qualities for a VS Angel. 

Sara Sampaio

Measurements: 32B-23.5-34

Sampaio, who is 5'8", is 24 years old and 114 pounds. On a regular basis, she trains two to three days a week, but when she's getting ready for the show, she ups that to four to five days a week, according to I-D. She's always been an active person, so staying in shape for her modeling career was never really a problem, but she does admit that it took a year and a half and a really good trainer for her to get the results she's always wanted.

She does a lot of planks and starts to run more when it comes down to crunch time before the big show, according to Hello Magazine. She also avoids foods that make her bloated, like bread.

Stella Maxwell

Measurements: 30B-23-33

Maxwell, who is 5'10", is 24 years old and 117 pounds. As someone who loves to be outdoors, she just continues doing stuff outside like going on hikes and playing tennis, according to Hello Magazine. As for her diet, she just eats healthy and drinks a lot of water because she knows that is what's important. 

Taylor Hill 

Measurements: 32A-22-33

Hill is 5'10" and a half, 19 years old and 112 pounds. When it comes to major events like this, she eats really clean three days before and drinks a lot of water, according to Vogue. As someone with a huge sweet tooth, she knows it's crucial to cut down on sweets the days before the event, so she stops eating candy.

For fitness, she does a lot of Crossfit the few weeks before, according to Fashion Gone Rogue. "I love how difficult it is," she explained. "The challenge of each workout really gets me pumped up for the show."

Since the show taped last month, the Angels are currently in the post-season phase of their VS Fashion Show diets, so last night on "The Late Show with Stephen Colbert," Angels Adriana Lima, Taylor Hill and Behati Prinsloo did "the one thing that America wanted to see" and ate some buffalo wings. The best part? They were wearing their famous VS angel wings! It was hilarious to see these supermodels eat a giant pile of wings after all this serious diet and workout prep!