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How To Lose That Belly Fat in 1 Week (I Tried It ... And It Worked!)

by Jeremy Ethier - July 20, 2024

Belly fat is stubborn and often the last area to go. But what if you could lose belly fat 3-4 times faster? Here's how to lose that belly fat in 1 week.

Is it possible to lose stubborn belly fat 3 times faster and make months of progress in just one week?

For the next 7 days, I'll be following a science-backed plan designed to do just that. I want to see how my body reacts and if this could be an easy way to shred down for the summer.

Belly Fat Baseline Measurements

Before I attempt to lose that belly fat, though, I need to know where I currently stand.

DEXA scans are pretty good at measuring overall body fat, which for me came out a little higher than I’d like at 15.6%, but they have major limitations when it comes to measuring belly fat.

This is where the ultrasound comes in.

Not to see if I’m expecting, but to find out the exact thickness of my upper belly fat, middle belly fat, and the most stubborn area, my lower belly fat.

After 7 days, we’ll see just how much these measurements have changed to gauge my success at my attempt to lose that belly fat.

But with that out of the way, it was time to start my diet. 

Diet

Calories

So, on a typical weight loss diet, I’ll usually aim for a calorie deficit of roughly 500 calories, which results in about 1lb of fat loss per week.

But because I'm trying to lose that belly fat fast, I’m eating just 1,200 calories with this diet.

This creates a deficit of 1,500 calories less than my body needs each day. It’s extreme, but if I can stick to it, this should lead to about 3 lbs of pure fat loss in just a week. 

What's this diet to lose that belly fat super fast called? I'll let Alberto Nunez tell you.

In the natural bodybuilding community, Alberto is known as “the go-to man” to get you absolutely shredded. I figured if there’s 1 person who would know the best approach to lose that belly fat in just 7 days, it’s him.

So, here's what he says:

"[The diet to lose that belly fat is called] ... the protein-sparing modified diet, and it's something you don't hear a whole lot of people talk about.

It’s definitely not a diet that is for everyone.

The diet can be run for anywhere from a week to three weeks. That's typically what I've seen work best in practice.

What are you really eating?

Nothing much other than protein, really. And you really have to leverage the fact that there's just a big deficit in place without you really doing a whole lot.

So you also have to be disciplined enough to know that, okay, I'm going to have to adjust my weight training, probably going to have to adjust other things when it comes to my lifestyle for a certain period of time."

Protein Intake

On a typical diet, I’d usually aim to consume roughly 1 gram of protein per pound of my body weight to prevent any muscle loss.

But with how extreme this diet is, that wasn’t going to be enough.

Here's what Alberto recommends for protein intake for those trying to lose that belly fat in just 1 week:

"I'd say anywhere between 1.5 to 1.75 g is a nice safe place. that doesn't leave a whole lot of room for the fun macros, the energy macros. (So you really are just limited. You're very limited in regards to what you can eat.)"

When I ran the calculation for this diet for myself, I realized I would have to eat a bare minimum of 250 grams of protein per day on a budget of just 1200 calories per day.

So when Alberto said my food options were limited? He wasn’t kidding.

Here's what he says about protein choice when trying to lose that belly fat in 7 days:

"It's going to be probably a lot of the leaner animal proteins.

Fish, maybe you can sneak in some leaner cuts of beef somewhere in there, but oh, it's going to be chicken breasts galore, probably some canned tuna.

It's not a pleasant diet by any means, but that's kind of what you're signing up for."

My Daily Meal Plan To Lose That Belly Fat

So here’s my daily meal plan to lose that belly fat:

  • Breakfast: Egg white omelet with celery
  • Post-workout: Built With Science protein shake
  • Lunch: 2 chicken breasts with light veggies
  • Dinner: More chicken and veggies
  • Dessert: Yep ... more chicken breast

However, if I want to maintain muscle through my goal to lose that belly fat super fast, just eating high protein isn’t going to be enough.

I still need to provide my body with a reason for them to keep my muscles rather than burn them off for energy. Which means I have to keep lifting. But not the way I usually do.

Lifting

Here are Alberto's weight training recommendations for anyone attempting to lose that belly fat in a short period:

"So your weight training should probably be something that lasts no longer than 20, 30 minutes, ideally.

[And as for how much cardio?] I would actually recommend maybe keeping a decent amount of steps just so that caloric maintenance that we're kind of building this from kind of stays intact.

But I wouldn't recommend someone do a whole lot of cardio at all.

I think steps and some basic weight training and then just do your best not to sloth around too much. It's going to be kind of unavoidable towards the end."

Now, research has shown that it only takes about a third of the volume to MAINTAIN your existing muscle.

This means that rather than doing 3 sets per exercise, I could do just 1 hard set, and that should be enough to protect my muscles from being burned without being too much for my body to recover from.

My first three days on the program actually went pretty smoothly.

I was definitely more hungry than normal, but it was manageable, and with the lower workout volume, my strength and recovery were still feeling really good.

Though I did have some pretty strange cravings hit me at night…

… so, who knows, maybe I am pregnant.

Supplements

Now, even though I’m not getting all the nutrition I need because of my strict calorie limit (we're trying to lose that belly fat fast, after all!), I’m trying to use a few key supplements to fill in the gaps, including a multivitamin, Omega 3s, and some clutch recommendations I got from Alberto.

Here are his recommendations for supplementation for anyone trying to lose that belly fat fast:

"Caffeine is definitely going to help tremendously, not just with energy, but in some people, it does suppress their appetite quite a bit.

I'd say protein shakes. Protein's kind of weird because I consider it part of my food budget as opposed to a supplement budget. It's like adult baby powder basically, right? But protein intake, I mean protein powders, they're a little bit more satiating I think, than people give 'em credit for."

Luckily, my Built With Science protein contains a whopping 29 grams of protein per scoop with only 130 calories. Which means it can easily fit within my calorie budget and it was definitely a nice treat to look forward to.

Want to try Built With Science protein? Here's 10% OFF — just use the code "BELLYFAT" during checkout. Click here to check it out.

How I Felt Throughout The Week

First Half Of The Week

First check-in: 3 days in, and honestly, I’m feeling great.

My energy levels are good and to control my hunger I’ve been taking advantage of some research showing that eating meals with smaller plates and smaller utensils can slow down your eating and lead to more fullness.

So I feel like with all these tricks and tools and the fact that I think I’m already seeing a bit more definition in my abs, I should be able to make it through the full 7 days with no problem.

Here's what Alberto had to say about my optimism:

"Anyone who's done this before will tell you that, oh, the first three days, especially coming off a period where you're eating quite a bit, it's like, this feels great.

I don't have to spend nearly as much time eating. I feel light, I feel good, nothing's going to happen.

But by day three or four, your body's really starting to bug you."

Second Half Of The Week

I was starting to feel a rapid energy drop going into the second half of the week.

I still needed to perform at work, get my steps in, and continue with strength training to ensure I maintained muscle.

But while I was able to make it through the workout my energy levels were continuing to drop.

As for my food cravings?

I was doing my best to try and keep my diet together while life was going on around me, but the longer I went into the diet the crazier those cravings became.

Alberto shares a similar experience:

"I vividly remember right around day three, spinach was starting to taste sweet to me.

I had bags of spinach that were, I guess you could say, part of my fun macros. It was my protein, my spinach, a few other random veggies.

But I remember tasting spinach, and I'm like, this spinach is sweet."

So when your body experiences a serious drop in calories, it starts to do whatever it can to tell you to eat.

Not only can your taste and smell become heightened, but your leptin levels can decrease dramatically.

Now, what’s leptin?

Well, it’s the hormone that tells your brain it’s full after a meal, and after just a few days in an extreme calorie deficit, leptin production can drop by up to 50%.

This meant that not only was my stomach physically feeling empty, but even the signals in my body meant to regulate my hunger were starting to go haywire.

To try and take my mind off the hunger, I tried purchasing a video game so I could give myself something to focus on, but by this point, I was feeling so mentally depleted that I couldn’t pass the “are you a robot?” test without asking for help.

Feeling absolutely depleted, the only thing left to find out is… was it all worth it? So I headed back to the lab to get my day 7 results.

Will I Repeat Trying To Lose That Belly Fat In 7 Days Again?

But before I find out, I already know that I will not attempt to lose that belly fat in such a short period again.

While it was fascinating to see my belly fat literally melting away despite barely working out and doing zero cardio, trying to lose that belly fat so fast came at a cost.

Trying something so extreme left me feeling exhausted, unmotivated, and completely depleted. When I did get to actually enjoy real food again, I had to spend the next few days resisting the urge to eat everything in sight.

Diets like this are exactly what cause so many people to yoyo diet and even develop eating disorders. You get fast results basically by not eating and eventually binge-eating it all back.

To truly lose belly fat and keep it off, you need patience, consistency, and a sustainable diet that you can stick to for several weeks.

We’ve helped thousands of people lose that belly fat by using diets they actually enjoy and can stick to long term. If you want more guidance, check out our personalized programs here.

But please, regardless of what the results show in the scans, do not try to lose that belly fat like I did in this article.

Results: Did I Really Lose That Belly Fat In 7 Days?

So. Did I successfully lose that belly fat in 7 days?

My DEXA scan showed that my body fat dropped from 15.6% to 14.7%.

That doesn’t sound like much, but it would usually take me at least a few weeks of dieting to achieve that.

But what’s interesting is the ultrasound.

Although my upper and middle belly fat didn’t change much since I didn’t have too much to lose there, my lower belly fat, which is the most stubborn area, dropped by over 30%!

In fact, the thickness of my lower belly fat dropped by half a centimeter! Which explains why I noticed my lower abs starting to pop out a little more.

TL;DR

  • To lose that belly fat in 1 week, I followed the protein-sparing modified diet and ate only 1,200 calories daily, which is 1,500 calories below my maintenance.
  • The combination of low calories and high protein intake (1.5 to 1.75 g per lb.) meant I couldn’t really eat anything else other than lean protein.
  • I had to step way back on my strength training (cutting ~ a third of my volume) and cardio because of the severe energy deficit.
  • The key supplements I used to fill nutritional gaps and maintain energy levels included a multivitamin, omega-3s, caffeine, and protein powder.
  • While I did lose that belly fat in 1 week, I know that I will not be repeating it again because of how unsustainable and unenjoyable the whole process was.

What's Next?

But despite the results, I wanted to get even leaner, so I decided to continue dieting for the next 6 weeks.

This time, using a more sustainable approach. Here’s how things are currently looking.

My plan is to head back to the lab for 1 more scan to see just how much more belly fat I was able to lose, and then write up an article for you guys revealing everything I did to easily lose that belly fat.

So keep an eye out.

Although this diet isn’t something I’d recommend to 99% of people, it does show just how important nutrition is for losing fat. This is why I’ve created a quick, healthy, budget-friendly fat-loss meal plan you can get started with today. Click here to check it out.

And again, if you need more personalized workout and nutrition guidance to lose that belly fat sustainably (and enjoyably), just take our quick, free analysis quiz below to discover the best Built With Science program for you:

Click the button below to take my analysis quiz to discover the best program for you:

Thanks for sticking to the end and I’ll see ya next time!

By the way, here’s the article summed up into a YouTube video:

How I Lost My Belly Fat in 1 Week (Using Science)

How To Lose That Belly Fat in 1 Week (I Tried It ... And It Worked!)

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