Jessica Simpson lost over 100 pounds, making all of our jaws drop when she revealed her significant weight loss transformation on Instagram. Beforehand, "my weight was in the high two hundreds," she admitted to Hollywood Life. "That’s a lot of weight — and I was just uncomfortable." After giving birth to her third child in 2019, Simpson decided it was time to make a major change. Over the course of the next six months, she dropped an astounding 100 pounds.

While most people lose weight by hitting the gym hard, Simpson’s way of slimming down came with a completely different approach. Sure, she enrolled the help of her long-time trainer Harley Pasternak and a nutritionist named Liz Josefsberg, but altering her overall lifestyle was the major change that helped to transform her life — and her body — completely. "The difference between this and the other times was that she worked out, yes, but her transformation was more about what she did on her own time," her trainer told People.

So how exactly did she do it? Here’s what Jessica Simpson really did to lose over 100 pounds.

Before beginning her weight loss journey, Jessica Simpson cleared it with her doctor

Before embarking on any weight loss journey, it’s important to get the all-clear from a doctor. That’s exactly what Jessica Simpson did before losing such a large amount of weight (via E!).

During all of her diets, Simpson has spoken with her doctor. As a spokesperson for Weight Watchers, it was vital for her to set this example to the world. At the time, the program wanted to make it clear that Simpson "will not be following the program during the pregnancy while her weight and well-being are being monitored by her obstetrician, as is recommended for any woman during pregnancy," Weight Watchers released in a statement (via The Hollywood Reporter). "After she gives birth, Jessica and her doctor will decide when she may resume following the Weight Watchers program."

Once Simpson gave birth to her third baby in 2019, she officially began losing a large amount of weight — following a discussion with her doctor, of course. "After having her third child, Jessica was more focused and dedicated than ever," her trainer, Harley Pasternak, told Shape.

Jessica Simpson ate three balanced meals every day

Eating less may help you weigh less, but it’s a lot less enjoyable in the long run. Luckily, Jessica Simpson got to enjoy three balanced meals each and every day during her weight loss journey. "The key for Jessica was moderation and learning to indulge intelligently," her nutritionist, Liz Josefsberg, explained to Hollywood Life — and that’s truly what it’s all about when it comes to losing weight.

Over the course of six months, Simpson adhered to something called the Body Reset Diet, created by her celebrity trainer Harley Pasternak. Every meal could even consist of something Simpson had always enjoyed before, as long as it included something with fiber, something with protein, and something with fat (via People). Each day, Simpson was consuming anywhere between 1,200 and 1,400 calories (via Healthline). It may not seem like much, but "she made sure to make her healthy food very flavorful," Pasternak told Shape. Even some of her very favorites, like Tex-Mex food, were able to be made in a healthy way (via GMA).

Jessica Simpson drank plenty of water to help her lose weight

Keeping properly hydrated is essential to anyone’s everyday health (and drinking water is vital as you age), but it can do wonders when it comes to weight loss, too. "Staying fully hydrated while losing weight is critical," her nutritionist, Liz Josefsberg, explained to Hollywood Life. "Much of the overeating we do is mistaking thirst for hunger," which only makes it easier to pack on extra pounds.

Simpson was drinking somewhere around 100 ounces of water each day during her weight loss journey, "which might seem like a lot," Josefsberg said. "But it is right for our bodies." The human body, she explains, consists of 60 percent water, so we need it in order for our organs to work properly. When our bodies are running best, they metabolize food fast, helping to burn calories and drop weight even more quickly than before. "Hydration is a secret weapon for weight loss," Josefsberg said, and it’s a really simple way to help our bodies to stay healthy and slim down.

Jessica Simpson focused her exercises around her family

Jessica Simpson dedicates a majority of her life to her family. They’re the reason she embarked on her fitness journey in the first place. "She was saying that her body has not belonged to her for the past decade," her trainer Harley Pasternak told People. "Not in a bad way, in a positive way — her body has been designated to create life and now it’s hers again." Simpson was committed to getting back her old body, but she was also able to do it while spending time with the people she loves most.

As if Simpson isn’t busy enough with her businesses, she’s also always running around with her three kids — which is actually a really great thing when you’re losing weight. "We’re constantly active," she explained to Hollywood Life. "And if our kids are going stir crazy, we all go jump on the trampoline. Just get it out, get the energy out." Losing weight was even easier when she didn’t have to decide between dropping pounds or spending time with her kids.

Jessica Simpson turned off social media for an hour every day

While dropping weight may seem like it’s obviously all physical, a lot of Simpson’s success depended on her mental health as well. That’s why she steered clear of social media for at least an hour every day she spent losing weight.

As a celebrity, Simpson has always been used to the ridicule that people would post about her online. Many times, it was about her body. "We all see our flaws," she told People, adding, "And mine were just out there for the world to rip apart." Eventually, she even got to the point where she stopped reading the comments people were writing on her Instagram posts, regardless of the fact that many were compliments.

Staying off social media for an hour before bedtime was something that her trainer suggested she should do to help her sleep, too. "That’s really important to control the hormones in our brain that are overwhelmed by the blue light on our phone, by the vibrations and alerts of our technology and the cortisol that’s released," he told Good Morning America.

Jessica Simpson worked out for only three hours each week to lose weight

When it comes to losing weight, many of us think it comes with hours upon hours of exercise. While Jessica Simpson did work out, it wasn’t for nearly as much time as we all would think — especially considering she lost over 100 pounds. "This was really a lot more emphasis on the behaviors outside of the gym," her trainer Harley Pasternak told Us Weekly.

Surprisingly, Simpson only spent three hours each week with her trainers. During each 45 minute session, she would focus on exercising a different group of muscles. To lose weight all over her body, her weekly regimens consisted of resistance exercises.

While keeping active is always important, her trainer was more concerned about what Simpson was doing in her everyday life. "Even if I or Sydney [Liebes, Simpson’s trainer] is working out with her for 45 minutes three times a week, or four times a week, there’s still 165 of the 168 hours that she’s not working out," he told Good Morning America. "That was the key to this transformation."

Jessica Simpson didn’t give up eating the foods she liked

Many people adhere to strict diets in order to drop pounds, but many of Jessica Simpson’s meals still included her favorite foods. "I personally don’t stay away from foods if I want something," she admitted to Hollywood Life. "I’ll have some of it, but I’m good at putting it down."

Having to make meals for three kids isn’t so easy when you’re trying to lose weight. Things like corn dogs and macaroni and cheese are just a couple of her kids’ favorites, and they’re both something she found herself occasionally indulging in too. "I have kids, so if I want, I eat like a kid," she said. Any other strict diet she’s tried in the past has been something she could never adhere to, so Simpson needed something flexible this time.

Her personal trainer, Harley Pasternak, even gave her the go-ahead to indulge in whatever she wanted each week. "I believe in ‘free meals,’" he told ET. "So, two ‘free meals’ a week. Do them on different days, the same day, it’s up to you." Finally — a weight loss program we can all get behind!

Jessica Simpson got at least seven hours of sleep every night

When it comes to losing weight, just dieting and working out won’t do. "So many people undervalue the importance of sleep in [weightloss] and weight management," Jessica Simpson’s trainer, Harley Pasternak, told E!. A major part of dropping pounds for Simpson was getting a solid seven hours of sleep every night.

Let’s face it: if you have a busy lifestyle, it’s not always easy to get an ample amount of sleep. In a society filled with high stress, falling asleep can feel impossible in the first place. Because of that alone, it was important for Simpson to plan her sleep schedule ahead of time so she was able to get enough sleep in. "Get at least seven hours of quality sleep at night, not just quantity," is what her trainer told her (via Us Weekly).

Why is getting a good amount of sleep so important? Crazy enough, a study published in The American Journal of Clinical Nutrition in 2009 found that people who slept less ate more calories. A lack of sleep can also cause your body to have more food cravings over the course of the day.

Jessica Simpson held herself accountable

Some days, it’s not so easy to get up and get going when it comes to losing weight. Because of that alone, it’s helpful to have someone there cheering you on along the way. That was Jessica Simpson’s trainer. Even though she only spent three hours a week exercising, she was still checking in with him every single night. "My clients, before they go to bed at night, send me an email," Harley Pasternak explained to Us Weekly. Simpson would send him a message detailing everything she had done that day and whether or not she had hit her weight loss goals. "To the extent that you check yes, it gives you this sense of accomplishment at the end of every day," Pasternak said.

Holding herself accountable is what helped Simpson get through the hard times in her weight loss journey. By reviewing what she had done every day, she was able to determine what needed to be done next. "If I haven’t moved enough, I’ll make sure and get in extra steps the next day," she told Hollywood Life. Reflecting after her daily reports was what helped her to do exactly that.

Jessica Simpson snacked when she was hungry

Cutting out calories is important when it comes to weight loss. However, if Jessica Simpson found herself getting hungry between meals, her diet allowed her to be able to snack.

The Body Reset Diet let Simpson enjoy two snacks each day. These small indulgences could consist of two different combinations that she chose from: a protein plus a fat, or some sort of protein with a fiber-filled snack. Many times, Simpson ate a few almonds or even green beans sprinkled with parmesan cheese (via Us Weekly). "We did not diet in a tasteless, extreme, radical way," her trainer, Harley Pasternak, told Good Morning America.

Realistically, nobody is going to be dieting every day, so it was important that Simpson had a way to enjoy snacking over the long-term. "It had to be more than just getting back from her baby weight, but how do I keep whatever I am doing now forever," Pasternak explained to E!. "That’s why we are not a big fan of doing any extreme diet or radical forms of exercise." When Simpson was done losing weight, she needed a new lifestyle that would make it last.

Jessica Simpson spent a majority of her time walking

"Shortly after she gave birth, as soon as soon as we got medical clearance to start walking, we had a daily step goal on her Fitbit," Jessica Simpson’s trainer, Harley Pasternak, told Us Weekly. She started with a small goal of 6,000 steps each day, and eventually worked herself up to where she was tallying 12,000 steps in a single day. Sometimes, she even went up to 14,000.

Not only is walking a great way to lose weight, but it helped Simpson to spend quality time with her family too. Many of her steps were made while walking with her husband, former NFL player Eric Johnson (via Shape). When that wasn’t enough, she would simply hop on the treadmill while she made business calls or binged her favorite television shows (via E!).

The things Simpson was doing to lose weight were something that her trainer wanted her to easily be able to incorporate into her lifestyle. "My work with her is more about the habits she’s created and kept up," he told People. These simple changes in her day-to-day are what ultimately helped Simpson to slim down.

Jessica Simpson didn’t drink any alcohol

Calories that could be easily cut out of any diet can come from alcohol, which is something Jessica Simpson avoided altogether throughout her weight loss journey. "She’s not drinking and losing all that weight. That’s for sure," her trainer, Harley Pasternak, revealed to Us Weekly. "She’s living a healthy, balanced life," and it’s something that was difficult for Simpson long before she dedicated herself to losing a large amount of weight.

After battling an addiction to alcohol for years, Simpson decided to make a drastic change in 2017. She gave up alcohol altogether, which helped her to reach her weight loss goals. Her mental and physical health also only improved from there. "There’s just no better gift," she told People regarding her sobriety. "There’s no better gift I can give my kids, there’s no better gift I can give my husband. More importantly, there’s no better gift I can give myself."

Jessica Simpson was realistic about her weight loss goals

While Jessica Simpson’s weight loss journey was all about taking back her pre-baby body, she knew she had to be realistic about what she really wanted. Instead of merely slimming down, Simpson wanted to make sure she was making healthy choices for herself over the long-run. "For me, it’s moderation," she told Hollywood Life. "I don’t put too much pressure on myself."

Her trainer, Harley Pasternak, was on the same page. He wasn’t all about using a scale each day (via People). The important part was that Simpson was making healthy choices that made her feel the very best about herself. "She is feeling like she did before she had [a] kid," he told E!. "In control of everything and such a great attitude of not beating herself up if she doesn’t eat perfectly everyday." A healthy body is a happy body, regardless of the number that the scale says.

Jessica Simpson persevered through the difficult days

The most important tip when it comes to tipping the scales is a pretty simple one. You have to believe you can do it, and that’s what helped to make Jessica Simpson’s weight loss journey so successful. "I am a determined person, so if I set my mind to it, I do it," she told Hollywood Life. "I couldn’t handle being so big and my ankles were swollen." At that point, it was time to take control of her own health, and she couldn’t have done it without surrounding herself with people who believed in her and cared about her well-being.

After weighing in at 240 pounds once her daughter Birdie was born, Simpson dropped over 100 pounds over the course of only six short months — all because she believed she could do it. "So proud to feel like myself again," she wrote on Instagram with a photo of her weight loss reveal. "Even when it felt impossible, I chose to work harder." Anybody who aspires to lose weight can successfully do the same if they only believe they can truly achieve their dream body, too.