Either this stupid thing is playing tricks on me or I just gained 3 pounds overnight.

Is that your first thought when you step onto the scale and see a number higher than you anticipated? 

You hit your workout yesterday and you’ve been counting calories to make sure you stay on track with your nutrition. 

The scale HAS TO be wrong.

So you step off and then back on again.

Same number.

You can feel your blood pressure start to rise and your mind is racing. 

Why did I gain weight overnight? 

Especially when I’m in a calorie deficit and being super consistent? 

Hey, I get it.

When you’re doing everything right, it’s pretty demoralizing to look down on the scale and see a number above what you expected to see. 

It makes you feel like all your hard work has been pointless.

The thing is, weight loss isn’t linear. 

So let me reassure you and ease your concerns—

A higher number on the scale doesn’t mean you suddenly gained a whole bunch of fat or put on all those pounds for real.

Daily weight fluctuations are 100% normal but what causes them?

Here are 9 reasons why the scale says you gained weight overnight.

 

What causes weight gain overnight?

 

1. You crushed it in the gym yesterday

If you lifted heavy and got a good workout in the day before, it can easily explain why the scale says you gained weight overnight. 

Here’s why…

After a strength training session, your muscles absorb water and glycogen (carbohydrates) to help your body recover.

This causes water retention, which translates to a bigger number on the scale.

Fun fact: You might see the biggest weight spike after leg day and lifting heavy on compound movements like squat and deadlift. 

That’s because your lower body has the most muscles, which makes the potential for water retention greater. 

 

2. You ate more sodium than normal

Let’s say you went out to eat yesterday (which you can 100% do, even when you’re on a diet), and the dish you got contained a lot of sodium.

Similar to lifting weights, eating sodium causes water retention. 

But again, water retention doesn’t mean you magically gained weight overnight. 

On the flip side of that, cutting back on your sodium intake may equate to weighing less because you’re not holding onto as much water.

 

3. You had a carb-heavy day yesterday

 

Carbs don’t automatically make you gain weight (eating too many calories does).

But carbs do cause your body to hold onto more water. 

See a pattern here?

I mean…Just break out the word “carbohydrates.”

Carb-o-hydrates.

 

4. You ate later in the day

You could’ve had a late dinner or maybe a little late-night snack before you went to bed. 

When you eat later in the day, the scale will say you gained weight overnight simply because your stomach has more food in it when you wake up.

It’s not fat gain.

But that does lead to the next reason…

 

5. You need to take a sh*t

This one’s pretty self-explanatory. 

I don’t think you need a manual on what to do if this is the case.

All I’ll say is…

Weigh yourself before and after going to the bathroom and this will make a whole lot more sense. 

 

6. You weighed yourself at a different time than usual

Let’s say your morning routine is to weigh yourself every single day first thing (which I highly recommend, by the way).  

But one day when you’re running late, you forget to weigh yourself.  

So now it’s later in the day (after a meal or two) when you finally get around to weighing yourself.  

Aaaaand…

The number on the scale is unfortunately higher than you’d hoped for.

But that’s because weighing yourself at inconsistent times can mean fluctuations in the numbers. 

 

7. You’re stressed

You may have heard that stress prevents your body from burning fat.

So let me be clear with what I’m about to say:

That is 110%, absolutely, without a doubt….

Not true at all.

Just think about it.

If everyone that was stressed gained weight, no one on this planet would be below 750 pounds.

The act of being stressed itself doesn’t lead to weight gain but cortisol can make you hungrier, which may lead to you overeating.

Stress does cause water retention though, and by now you’re well aware of the fact that water retention can result in weight fluctuations. 

8. You had a poor night’s sleep

Insufficient sleep (whether it’s quality or just not getting enough) brings on stress.

Stress comes with cortisol and water retention, as we just talked about. 

 

9. It’s that time of the month

To all my ladies out there, this one applies to you specifically, obviously.  

Leading up to your period, your body will hold onto more water and salt, which can make it look like you’ve gained weight overnight. 

This temporary weight increase may be as little as 1 pound or as high as 7 pounds.

It really just depends on the individual.

But just know this is totally normal and you haven’t truly gained all those pounds.

 

Now you don’t have to worry about daily weight fluctuations

Breathe in, breathe out.

The scale may say you gained weight overnight but now you know that just isn’t the case.

Put your anxiety at ease and refer back to this list the next time you’re staring down at the scale and questioning, “Why did I gain weight overnight?”

• You could have had a great weightlifting session the day before
• You ate more sodium than usual
• You had a carb-heavy day yesterday
• You had a late dinner or maybe a midnight snack
• You need to go #2
• You had a few alcoholic beverages last night
• You didn’t weigh yourself when you normally do
• You’re stressed
• You were tossing and turning all night
• Your period is coming up

Gained weight overnight FAQS

 

Why did I gain weight overnight in a calorie deficit?

Being in a calorie deficit doesn’t exempt you from normal, daily fluctuations in weight (the overwhelming majority of which are just due to water retention). 

The scale could be up today and then back down again tomorrow.

You won’t lose weight every single day, even if you’re in a calorie deficit.

That’s just how things work.

As long as your long-term weight loss trend is a downward one, you have absolutely nothing at all to worry about. 

 

How do I get rid of overnight weight gain?

There’s nothing to get rid of because overnight weight gain and fluctuations in the scale are completely normal.

Know that there’s a difference between fat loss and weight loss. 

So even though the scale might move up and down for a variety of reasons, you’re not gaining fat when it jumps up overnight. 

Why am I gaining weight when I barely eat?

First off, your body’s not in starvation mode so don’t even go there.

And second off, I hate to break it to you but the reason you’re gaining weight even though you “barely” eat is because you’re eating way more than the 1,200 calories a day you have in your mind. 

The foods you’re consuming are most likely calorie-dense, meaning they contain a lot of calories for the small amount you’re eating. 

So while you may not be eating a lot, the foods you’re eating are higher in calories, which is preventing you from losing the weight you want.