Most of you reading this will know that it is very possible to lose 5lbs in 4 days. Specially if you haven’t been dieting for a while! However this question was asked in a Keto group I am a part of and I thought it would be good to share a bit of the science.
Here is how the conversation went:
Petra: Is it possible to lose 5lbs in 4 Days.
Me: Yes, very possible, it is water weight though. Easy to gain back too.
Helpful Lady #1: Yes, water weight.
Helpful Lady #2: Great job, water weight for sure.
Helpful Guy #1: You can lose 10 lbs of water weight or more the first week!
Helpful Lady #3: Congrats on starting this new way of life. That first week weight drop with water weight is so cool!
Petra: Well I did it…. and it isn’t water weight.
Helpful Lady #2: What makes you think that?
Petra: I just know.
Helpful Lady #2: Any Data on that? What did you do.
Petra: I didn’t eat.
(insert many people trying to explain water weight and get an idea of what she has actually been up to and try to be helpful)
Petra to Me: Don’t be rude, it isn’t water weight, it will not come back, if it does I will just not eat again till it is gone again.
Me: I am not being rude, it is just science. You might well keep it off with this way of life. Water weight though is fickle! You are made of 50% water, so the likelihood of just starting a new diet and losing real fat so fast isn’t likely.
Petra: I didn’t lose water weight. Don’t be rude.
Me: Ok…. lets assume you are an athlete. You haven’t told us anything about you, how you are eating or working out, but lets go with the best case. So you say you lost 5lbs of fat (on keto most of us also lose 10% lean muscle but that is less than other diets and thus why a lot of athletes are now choosing keto but that is not what this post is about, lets stick with fat.)
So that means you are saying you burned 17,500 calories in 4 days. I don’t know if you had anything at all to eat but lets say you ate enough to maintain your basic body functions. So that leaves some how burning 17,500 calories another way. Lets assume you like to cycle! Ok so you cycle for 2 hours and an average person burns about 500 calories. But that will not add up for you, so lets say you cycle 7 hours to hit 1lb fat loss! But that still isn’t the 5lbs your talking about. So you would have to cycle for 70 hours out of 4 days. That is a heck of a lot right?
Petra: Doesn’t reply…. deletes her post.
So given that we are 50% water, why is it that we are so upset when we hear that we lost water weight? Is it fear that it could easily come back? Weight fluctuates so much and it can explain why some weeks we are up in weight even though we did it all “right” and some down. So much effects if we hold on to water or not. No matter what though, if we are getting thinner, our water weight must go down too. 50% off 200 is 100, so if we plan to say go from 200 to 150, that will be 25lbs of water weight right? (if I am understanding the math correctly). Lets celebrate the water weight loss for what it is!