Wanna Lose 10 Pounds in a Week?
Updated: Sep 29
If you landed here, you probably want to lose 10 pounds in a week...or are at least intrigued by the possibility and idea of it.
Maybe you have a vacation, wedding or other time-crunched special event you had a big deadline to look your best for, but, as if often does, life got in the way and you failed to give yourself ample time to lose 10 pounds of fat (more on this later).
Now you are up against the clock...but are willing to do ANYTHING to get the fat off fast. Like 7 days fast.
Is It Possible?
Can you lose 10 pounds in a week? Theoretically, yes, you could (more on that below). Anything is possible.
...just because something is possible DOESN’T MEAN IT’S REALISTIC, LIKELY, OR SAFE!
What Would It Take to Lose 10 pounds in a week?
Now, before I tell you what, exactly, it would take to lose 10 pounds in a week, let’s make a clear distinction: I’m talking about 10 pounds of BODY FAT-NOT WATER WEIGHT-IN A WEEK.
Losing 10 “pounds”, and having that show up on a scale, in a week, honestly, can be done pretty easily (not that I’d recommend it).
Cut back on your calories slightly, cut your carbohydrate intake down to basically nothing (no carb diet), and make up your daily calories of mostly all protein.
Done for 7 straight days, THAT will cause a massive loss in WATER weight. Eliminating carbohydrate completely will eventually cause the carbohydrate you have stored in your muscles and liver (which is bound by water in the form of glycogen) to be used.
If that carb is not replenished, the water weight will “woosh” (this is a short-term, transient effect which doesn’t last past a week). This, combined with a high protein intake-protein is expensive for the body to digest and absorb-keeping dietary fat intake very low, and a modest calorie deficit (not necessarily having to track calories...just eating a little less than normal in terms of portions) will cause a dramatic drop in scale weight in a week’s time.
(Let’s keep in mind it’s highly unlikely anyone can or could eat like this on a long-term basis as a lifestyle)
Now, will it end up being exactly 10 pounds doing it like this, without meticulous tracking and a very well defined, more intense, calorie deficit? I have no clue, but, I’ll anecdotally tell you it’s not uncommon-and this is why KETO or very low carbohydrate diets are so popular-to see people drop 4-8 pounds in a week of initially doing this.
So, if you were looking for an easy “hack” to drop a lot of water weight in a week...there you go. This is no way will improve your body composition to any significant degree, but if you are one who gets super “stoked” (to each their own) to see the scale drop way down fast (means nothing), I’d imagine you’ll like this.
But I digress...
Now, Let’s Talk About What It Would Take To Lose 10 Pounds of FAT in a Week
I want you to read through the above image closely. I mean...look at it hard.
That’s what it would take-the restriction and exercise needed-to lose 10 pounds in a week.
I just chose a random reference adult female for this example. I’d consider a 160 lb. female at 32% body fat (that’s about the 40th percentile) pretty representative of a “normal” female. Let’s just refer to her as “Justine” going forward.
I calculated Justine’s maintenance calorie intake using the Katch-McArdle equation, which is widely regarded as a very accurate estimator of total daily energy expenditure and calorie requirements. You can calculate your own maintenance calories using the file I attached below:
In order for Justine to lose 10 pounds in a week (the majority of it being body fat), she would need to create a 35,000 calorie deficit below her current maintenance needs (a 5000 calorie DAILY deficit). Her current maintenance calories are 1866 and she still has to eat something right? So lets shave 1000 calories a day off of her maintenance intake (this is an insane reduction of over 50% of her normal calorie intake).
So now Justine is going to be eating 866 calories per day (insane and in no way sustainable). Problem is, she still has to create an extra 4000 calorie daily deficit.
She really can’t eat any less (this is 5.6 calories per pound of current body weight), so that leaves her in a place where she has chew up (pun intended) a metric crap ton of calories through activity).
I went to exrx.net to determine how many calories she could burn jogging at 5.0 mph at her current body weight of 160 lbs. (pretty typical form or exercise). At 160, Justine will burn roughly 10 calories per minute jogging at 5 mph (a lighter person will burn less and a heavier person will burn more). That means she has to RUN FOR 400 MINUTES DAILY TO BURN 4000 CALORIES! That’s 6.6 HOURS! While eating next to nothing!
Here is a little video I made diving deeper into all this:
The Take Home Message
I hope you see that while, yes, it’s technically possible to lose 10 pounds in a week...it’s probably not the least bit realistic in terms of the time commitment and restriction necessary...and you might not live to tell about it :)
A much better approach, if you have a specific weight loss goal, is to target losing about .5-1% of your starting body weight per week and leave yourself enough time to do it in a sane, sustainable, not overly restrictive way.
What would this look like in Justine’s case?
Starting weight of 160 lbs.
Goal of 150 lbs.
Target weight loss: .5% of starting weight/week (.8 lbs.)
Time to lose 10 lbs.: 12.5 weeks
Daily calorie deficit needed: 400/day (not 5000 lol)
Be VERY leary and skeptical of outrageous claims which promise losing a large amount of weight in a short amount of time. If you actually run the numbers, you’ll quickly find out large-scale weight loss in minimum time likely isn’t possible. Sustainable and sane ALWAYS wins!
If you found this article helpful and informative, I’d REALLY appreciate it if you could share it on your social media. Best of luck on your fitness journey!
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