The faster we burn off fat, the better, right? Wrong. In this video, you’ll learn the truth about losing fat in the most effective way. What most people don’t realize is there’s actually an upper limit as to how much fat you can lose every week. And if you try to push past this weekly limit by doing more cardio or eating even less for example, then you’ll now start to lose substantially more muscle instead of fat. Do this for months on end which many people unfortunately do, and you’ll eventually end up with a “skinny fat physique” – with too little muscle and still too much fat.
So now the real question becomes what’s the MOST amount of fat you can lose per week while minimizing muscle loss in the process? As this is going to better enable you to attain the lean, muscular physique you’re after instead of just winding up skinny fat. And to answer this question, we’ll use the findings of a 2005 paper by researcher Dr. Alpert, who used various fat loss studies in an attempt to quantify the maximum amount of fat one can lose per day without excessive muscle loss. What he found is that the body is capable of burning body fat to use for energy at a maximum rate of 31 calories per lb of body fat per day. Once you exceed this rate, the body then has to tap into your muscle mass in order to make up for its energy needs.
Well, if you’re truly seeking to lose fat as fast as humanly possible, then here’s what you’d do. First, find out what the maximum daily calorie deficit and weekly fat loss number would be for you using the process I outlined earlier. Then, to achieve this daily deficit, you would use a combination of eating below your TDEE or maintenance calories, performing regular resistance training, and throwing in additional cardio. Then, you simply monitor your body weight throughout the weeks and try to hit your target maximum weekly fat loss number.
Then as you progress and your body fat continues to decrease, you’d want to slow down your rate of fat loss to minimize muscle loss by again re-calculating what your maximum weekly fat loss number would be at your new weight and body fat percentage. So over time, the rate at which you lose weight should slow down.
And that’s basically all there is to it. But, with all that being said, I do want to provide some pre-cautions.
First of all, keep in mind that this protocol is a very aggressive approach that employs a fairly large calorie deficit, high activity, and a fast rate of weight loss. For some who are more experienced this may be completely doable, but for most people especially those just starting out with their fat loss journey, it’s just unrealistic and very difficult to adhere to, and you’d be much better off taking a longer, less aggressive approach that you’d be more likely to stick with. Second of all, as researcher Dr. Albert points out, even if you’re under this 31 calorie/lb limit I outlined it doesn’t mean that you won’t lose muscle mass.
It simply represents a threshold value past which the rate of muscle loss starts to become exponentially large.
So if you’re truly seeking to maintain as much muscle mass as possible or even build muscle while losing fat, then again a less aggressive deficit would be best.
But all in all, if you get motivated by seeing results fast and can adhere to a tough protocol, then, by all means, go for it. Otherwise, taking a slow and steady approach and making positive long-lasting changes to your lifestyle is what I’d personally recommend, as that’s more often than not what delivers the best results.
hope you were able to see that sometimes burning fat faster isn’t always better. Within my Built With Science programs, we not only put careful thought and research into helping you lose fat efficiently, but we’ve also created in-depth tutorials for tracking your calories and macros so that you can execute a cut perfectly.
To join today, simply head on over and take the starting point analysis quiz to discover the best program for you:
MUSIC: soundcloud.com/lakeyinspired
GRAPHICS: Vector art from Vecteezy.com
STUDIES:
ENERGY DEFICIT WEIGHT LOSS
WEIGHT LOSS RATE RECOMMENDATIONS
METABOLIC RATE WEIGHT LOSS
HUMAN FAT STORAGE

What do you think about this fat loss protocol? Comment below! Hope you all enjoyed this one – let me know what other topics you’d like to see me cover and I’ll get on it! Cheers!
Let’s pretend this is true (calorie restrictions aside) this is how long it will take to lose all fat at different levels:
1,000,000 pounds of fat = 100 days.
1000 pounds of fat = 100 days
100 pounds of fat = 100 days
50 pounds of fat = 100 days
20, 10, 5 pounds of fat = 100 days
0.0000000001 pounds of fat = 100 days.
Good system. Maths adds up
I just lost 5 lbs in 5 days. That's water fasting and 25k steps/day. No noticeable loss of strength in the gym.
So if I'm 100 pounds overweight, should my max deficit be 3100 calories a day?🤔
Ok so now I know what my daily kal deficit is, how do I find my tdee to subtract it form ? You left that part out.
I found, when I lost too much weight quickly, I got weak…
The paper is just theoretical drivel with no basis in reality…
I lost a size every 2 weeks adding 15k steps a day of walking to my 1500 calories diet. Went from US size 10 to 4 in 6 weeks.
Was still only losing the 2 pounds per week that i lost before the walking but lost 2 inches all over every 2 weeks. So lost a size after losing 4 pounds rather than the usual 10 to 14 pounds it takes to lose a size.
According to this math, I should be completely starving myself while burning 250 calories in the gym each day to lose 4lbs per week.
Just fast 😊
Laughs in David Goggins
1% a week
Jimmy here
That pinging drive me mad .
Does this equation work for women
Does this equation work for women
I did a 72 hour fast, lost fat and maintained muscle. I wouldn't suggest it, but it definitely worked
What an overcomplication for something that simple – but you need the content…
that is just silly. Its based on a study that takes low ingest on carbs subjects. Atletes can oxidize around 70% of fat in a slow long run of 14 km. You do that three times, and yes, there are many people that can do it, and you are around 300 grams of fat, way over that limit. And thats nowhere near the real limit
One of your best videos I've seen. Great job
I lost 5 pounds of fat in a really unhealthy way once..it did pay off the work but I’ll never do it again, I fasted for a week and ran for an hour, strength trained for an hour AND walked for 30 minutes everyday for the week.. I was about to faint but thank god I stayed hydrated and took vitamins because if I didn’t I would have been in serious conditions..DO NOT EVER TRY THIS BEFORE CONSULTING A YOUR DOCTOR . Or don’t even do it at all. It’s really bad for your physical and mental health …
this video is off because i have lost 14 pounds in a week by just running 10 miles a day it when you run you use almost every muscle in your body so i did only lose fat not muscle
I’ve been trying to lose fat I was 74 and I’m going for 65 after nearly 4weeks I am 72kg and a few days ago I was 71 so I feel like I messed up and I always eat too much on the weekends
Goggins did 4kg a week for 12 weeks
If going by the math at 2:24 i can lose 7.3 lbs of body fat per week and minimize muscle loss, yes ik im heavy
This is great info! I actually lost 14 pounds doing the hermq program. Results shocked me!
3-4 pounds a week is reasonable
I like the video and your explanation is relatively straightforward. However, I do think that you can push it a bit more if you are properly eating the macronutrients you need and continue to lift several times per week. The formulas outline give you a good starting point though
Bro I can lose a pound of fat A DAY! It’s insane.
Suck when u can only lose 1-2lb per week. But I can gain 1-2lb a DAY!
This video came at the right time, hella groovy!! <3
This is not thinking about the issue clearly. This is the same logic where people say you should walk instead of run to reduce fat. Walking is 90% efficient at breaking down fat over muscle and sugar. Running is only 80%
But of course I'd rather burn 800 calories at 80% efficiency an hour than 200 calories at 90% an hour.
Same goes with this… Losing 15lbs a month is very doable if you have decent cardio endurance and a good 800 cal macro plan.
Just like the lifter who doesn't mind looking fat for a month before his cut phase… The dieter shouldn't mind looking skinny for 2 weeks.
The muscle you lose will grow right back and you'll be hitting pb in a month or two.
What has been proven to fail for people time and time again is trying to be hungry for 6 months to a year.
Think about anything you're working on in life? Is it easier to do 2 things at once for a long time or is it easier to focus on one and then switch when finished?
Which method goes faster?
If you are trying to cut and get stronger at the same time, you are doing it wrong. The guy who cuts and gets back to max health / caloric lifting is more efficient.
Thanks you so much I used to consume 400 calories and I thought it was sufficient thanks for helpin🙏🙏🙏🙏🙏
You didn’t lose muscle. You lost visceral fat and glycogen. Your body isn’t smaller — it’s just no longer bloated. Real muscle takes time to build and doesn’t vanish from a few cardio sessions.
Most people can’t even measure lean mass properly. But they act like they have lab-grade scanners in their abs.
Lose fat = optical shrink. Keep protein high = muscle preserved.
There’s no scientific proof that cardio causes muscle loss. What you’re seeing is just the loss of glycogen and visceral fat, which makes muscles look temporarily smaller — not weaker. It’s illusion, not atrophy.
205 Lbs, 36% fat per Dexa scan = 73.8 pounds of fat. 73.8 x 31kcal/lb/day = 2, 287 cal per day deficit. BMR = 1846. So as long as I eat -441 calories?
I don’t believe this… this rules out the keto diet
I like your video. And love that it's not so long and you said what you said with the Info we needed. Thanks for that!!! 🎉 I subscribed!!!
I'm currently on my Weightlossjourney and I have like 7 pounds I need to get rid of to April 1st. 😂 And then I have about almost 40lbs more to go😅 but we got this!!! Whoever needs or wants to lose weight, you can do it!!!!! ❤🎉🎉
Please add metric units to your videos. 🙂
Love your videos..so informative!
With PEDs involved, the upper limit to lose fat is very high (1lb of pure fat or even more per day) with little to no muscle loss at the same time.
Great channel boss. I saw you before bit I had to come back and I decided to subscribe
Your content is so good, articulate and nobody amd I mean NOBODY pack such science based info into such short video.
Thank god I’m just like John 😹
0.5 kg per week
This fellow could put a glass eye to sleep 😂