You've probably heard how people are on a weight plateau and then WHOOSH they suddenly lose a number of pounds. Sometimes this is attributed to water in fat cells being flushed out of them. What is it really due to?

If you've heard this is due to water being trapped in fat cells, be sure to read my article on why Fat Cells Don't Store Water. So, if the weight loss isn't due to water flushing out of fat cells, what could it be caused by?

The answer is glycogen.

Glycogen is a type of sugar that is a back-up energy storage system. It tends to live in the liver and muscles. You might have heard of "hitting the wall" in running. This is when your body changes over from burning those glycogen stores and moving on to fat-burning, which is good. So this is a natural cycle the body has to handle energy use.

Glycogen doesn't hang out on its own. It tightly binds to water, so those stores of glycogen in the muscles have with them a substantial water weight.

When you burn that glycogen, the water is released as part of the burning process. So let's say you burn ten glycogen units. Now those matching ten water units are freed and peed out. You can see how, if you burn a bunch of the glycogen, you suddenly release a substantial amount of heavy water that was just hanging out with that glycogen, and you pee all that water out.

WHOOSH! You just lost a lot of weight!

So let's say you eat precisely for a week, and your glycogen levels are therefore low. You have a "binge" day where you replenish those glycogen levels and they bind with water. The next day you go back to careful eating. You burn through those glycogen levels and WHOOSH you lose a lot of water weight. You're back to your state again with low glycogen levels.

Here's an article from The American Journal of Clinical Nutrition that talks about some of the mechanics involved.

The American Journal of Clinical Nutrition on Glycogen storage and "easy weight loss"

It's important to note this is not fat loss! This is the problem with just looking at your "weight" as a single number without knowing your percent fat, percent water, and so on. You might be sad when you're at a "plateau" even though you're still losing fat. You might be happy when you "lose weight" even though that loss is healthy water leaving your system.

What you need to track is your body fat levels. That's the true measure of how healthy you are. You want those fat levels to reduce in a safe, healthy manner.



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