Wilson paired up with trainer Jono Castano, who has featured heavily on her socials all year working out alongside the star.
"Friday vibes but @rebelwilson has been putting in the yards 7 days a week," Castano captioned a post alongside Rebel in January. "Proud of you gurl."
The comedian/actress told Entertainment Tonight at the time that she started losing weight while filming the movie Cats.
"I lost eight pounds shooting my number, in four days," Wilson said. "One, because there's a lot of physicality ... But also, they heated up the set very high, to almost 100 degrees Fahrenheit (38 degrees celsius), so that we could never cool down."
Castano later revealed the extremely hard work that went into Wilson's workouts.
The personal trainer took to Instagram to share a clip showing the actress as she smashed out a core and upper body workout using a medicine ball.
Her workouts include lifting tyres, rope training, medicine balls and boxing sessions, with her trainer writing on Instagram earlier this year that the actress had been putting in solid hours.
In an interview with E!, Castano explained he had created a specific programme for Rebel covering six days.
He said he encourages his clients to workout daily for 45-minute sessions, noting "results come through consistency".
His personalised programme for the star included high-intensity interval training, mobility, weights, resistance, technique and tempo. Rebel has one day off a week to rest her body.
He said he believed that anyone who struggled to find the motivation to exercise would benefit from working with a personal trainer.
"Training is not just about the 45 minutes, it's also how you can keep someone motivated outside of that time," he said.
The physical changes to Wilson's body were starting to show, along with her growing confidence.
The star started to get people talking with gorgeous Instagram posts showing her slimmed-down figure.
Come May, the star opened up about her weight loss goal, admitting to fans that she aimed to reach 75kg.
"Even if you have to crawl towards your goals, keep going it will be worth it," she posted at the time.
"Try and give a little bit of effort each day … I know some days are frustrating as hell, you feel like giving up, you get annoyed at the lack of progress … but good things are coming your way," she wrote.
"What are your goals this year? I'll be honest with you guys – with my Year of Health mission I'm trying to get to 75 kgs and career wise am trying to get one of my movies into production before the end of the year! Both of these things are requiring a daily effort and there's constant set backs – but I'm working hard x," she told fans.
And set backs there definitely were. While chatting to Sunrise in June, the star admitted that the impact of Covid-19 meant her "ear of Health was an even harder goal to achieve.
"I've been doing a lot of working out, which was hard with the coronavirus restrictions because I had to go out to the park and just lie on the dirt doing my sit-ups," she revealed on the programme.
"Now it's getting cold in the mornings, so I'm glad the gyms are reopening."
In an interview with The Sun, she opened up about how she was paid to stay a larger size by film bosses.
"It's not like I want to lose weight and get to around a certain number. It's more than that, it's about dealing mentally with why I was overeating and I had a job where I was paid a lot of money to be bigger, at times which kind of can mess with your head a bit.
"So now I'm just trying to work on the mental side and the physical job and doing a lot of personal training and, and on the nutrition side like it's, it's cool I should probably write a book at some point about it because people seem to be interested."
Rebel has previously spoken about how her American acting agency snapped her up because they had no one that looked like her on their books.
It was her role as Fat Amy in Pitch Perfect that catapulted her to fame and had her making a lot of jokes about her weight.
The star's transformation wasn't going unnoticed by her celeb pals either.
Wilson posted a photo of herself smouldering in a figure-hugging blue dress by Alex Evenings in late August – and soon celebs were flooding the comments section.
"Werk. You delicious babe!" said Oscar-winner Octavia Spencer.
"If I could like this pic numerous times I would," wrote fellow Aussie actress Ruby Rose.
Wilson's close friend and frequent workout buddy Hugh Sheridan wrote: "You look so HOT!" while Olympian Rennae Stubbs chimed in: "Look at this supermodel."
"Sweet baby Jesus! You look amazing," wrote Jono Castano.
Come September, Wilson went public with her relationship with millionaire Jacob Busch.
Lucky for us and everybody else invested in Wilson's life, she was proud to give share plenty of details on social media.
Wilson first showed off Busch, 29, at Prince Albert's Planetary Health Gala in Monaco, making it their official red carpet debut.
The two were introduced in 2019, but only started dating when Wilson returned to the US after quarantining in Australia during the Covid-19 pandemic.
"They are officially boyfriend and girlfriend," a source told People magazine. "He's a gentleman, has very old school manners and treats her well.
"He is also very health conscious and they've been motivating each other with their health journeys."
The handsome fella is a member of Anheuser-Busch brewing dynasty and is rumoured to be worth more than $140 million.
Anheuser-Busch manufactures beer brands including Budweiser and Rolling Rock.
Their relationship was soon made Instagram official when Rebel documented the pair taking a private jet to Monaco for the event.
Following the Gala, they stayed in the area for a little holiday, peppering both their Instagram accounts with updates from on board a lush yacht off the coast of Monaco.
In October, the Cats actress revealed that she was only 3kg away from her weight goal.
"Happy Sunday everyone! Gearing up for a great week ahead," she wrote on Instagram.
"This week was super busy but I got up super early 3 times (6am) and went on a hike ... even did a couple of 100m sprints to get the heart rate even higher (although my 'sprint' is probably someone else's 'slow jog').
"But I felt proud of myself and now only 3kg away from my goal weight! Rebs x".
Working hard was paying off for the actress, but it wasn't all working out and eating healthy.
Wilson was enjoying her life, taking another trip with her boyfriend in mid-October to Mexico and uploaded a number romantic shots with her boyfriend, including shirtless photos of Busch.
Come Halloween and Wilson was proud to show off her body in a sexy costume.
Donning a black leotard with a midriff cut-out and silver bust detail while dressed a "coronavirus killer", the star laughed confidentially as she brandished toy nunchucks for an Instagram video.
"Just call me: RONA (Warrior Princess) … destroying 'rona wherever I go," she captioned the playful post.
Edging toward the end of the year, Wilson had started to reflect on her journey, becoming more candid about her reasons for losing the weight.
In November, Wilson told Drew Barrymore on The Drew Barrymore Show her vice was her sweet tooth.
"I love desserts," she said in the video interview.
"And I've tried, like so many women out there, I've tried fads and diets and things before and I'm like, I need to do a really holistic approach to this, this time."
She went on to say "stress" led her to reach for sugary treats.
"I think what I mainly suffered from was emotional eating and dealing with the stress of becoming famous internationally – there is a lot of stressful stuff that comes with it – and I guess my way of dealing with it was eating doughnuts.
"So I was working on the mental side of things and thinking why was I doing that? And why wasn't I valuing myself and having better self-worth?"
"My diet was mainly all carbs," Rebel said.
"Which were delicious but for my body type I needed to eat a lot more protein."
She added: "So I've lost, I think it's like 40lbs [about 18kg] this year so far and I want to lose a few more."
The comedian, producer and actress went on to say she "loves her curves", adding that her focus on exercise and diet has been about leading a healthier life.
"I love my curves and stuff; I don't think I'll ever go too skinny," she said.
"I feel so much healthier and I don't know whether it's a thing with ladies when you turn 40, I feel like I've really come into my own now, and not just with health but with my career as well."
Further opening up, she went on to discuss to E! News shortly after that she was diagnosed with polycystic ovarian syndrome (PCOS) when she was younger, which made her rapidly gain weight.
"I've been overweight for about 20 years," she told the publication. "I started gaining weight when I was about 20. I had something called PCOS and I gained weight rapidly.
"It's just a hormone imbalance and you gain a lot of weight usually and that's how it manifested in me.
"Sometimes, I feel sad, but then at the same time, I worked my body to my advantage. I like being all sizes. It's just now turning 40, I am more health-conscious and thinking of starting a family."
Wilson said it was important for her fans to know the difference between being "skinny" and being "healthy".
"I don't want to project the message that being smaller is better because I don't really believe that," she continued. "I was just engaging in pretty unhealthy habits, like eating a tub of ice cream every night and stuff, that wasn't actually helping me. It just felt good in the moment."
Following that interview, she went on to reveal to People magazine about her previous 3000-calorie-a-day diet.
"Before I was probably eating 3000 calories most days, and because they were normally carbs, I would still be hungry," she confessed.
"So, I've really changed to eating a high-protein diet, which is challenging because I didn't used to eat a lot of meat."
The actress added: "I eat fish, salmon and chicken breast."
"It doesn't mean every week is a healthy week," she explained.
"Some weeks are just write-offs, and there's nothing you can do about that."
Instead, the star is looking at the big picture as she works to obtain her goal weight.
"I'm just trying to go for overall balance, overall healthy balance," said Wilson.
"I have this state of being, which is not my quote, but I go, 'Nothing is forbidden'.
We'll be like, 'Should we get In-N-Out burger?' And I'm like, 'Nothing is forbidden.' I can go there, I just might eat half of what I used to eat before. You know? And I'll have a burger, and a few fries, and then you feel fine."
"I think I was emotional eating, and overeating at times, because I wasn't loving myself enough either," she said.
"And it does come down to that self-worth and self-love."
Come the end of November and Wilson could happily reveal to her fans that she had reached her goal weight, with a month still up her sleeve.
"Hit my goal weight with one month to spare!" Wilson posted to her story alongside a photo of a scale, which read 74.6kg.
"Even though it's not about a weight number, it's about being healthy, I needed a tangible measurement to have as a goal and that was 75kg."
After reaching this major goal, the star sat down for an hour-long Instagram Live session with her fans, engaging in one of her most revealing conversations.
The star opened up about a near-death experience, again how the industry didn't accept her weight loss, and how she has now frozen her eggs.
Getting right into it, Rebel explained that: "Industry-wise, there were a lot of people who wanted me to stay as Fat Amy," Wilson said, referring to her character in the movie franchise Pitch Perfect.
"And at the end of the day it is my life and my body and Hollywood had in a way typecast me but I didn't want to stay like that.
"It makes me sad sometimes that I didn't value myself enough before all of this to get healthy."
In one of the biggest revelations, Wilson opened up about the time she "almost died", which also happened to be when she was at her thinnest.
"I was at my skinniest when I had malaria when I almost died, when I came out of hospital everyone was like 'Wow what did you do?' I almost died …
"But I probably haven't been the weight I am now since like high school, which has been interesting, but for 20 years I have been a bigger person."
During her Live video, the comedian fought back tears as she revealed to her fans that she did not treat her body with the "love and respect" it deserved in the past.
"I would wear my weight as a bit of a barrier, so people wouldn't get close to me," she continued.
"I wasn't valuing myself, and telling myself negative things. That was hard. I'm trying to change those patterns, so you're more loving and treating yourself with respect.
"I'm working on self love, and that's a hard concept to master."
The actress went on to explain that another very important reason why she wanted to get healthy this year, was because she wanted to freeze her eggs, enabling her to start her own family in the future.
She added: "I was thinking about fertility and having good quality eggs in the bank, so I was like – OK, I'm going to do this. I'm going to get healthy."
And boy, has she gotten healthy!
Rebel has achieved a lot in one year, not only with her weight loss but how she has worked on herself internally too.
We can only imagine what we will witness with Rebel come 2021 as she continues on her incredibly journey.
