5 Reasons The Scale Went Up Overnight (And What To Do About Them)

You’re finally losing weight.

You’ve been tracking your calories.

Eating enough protein.

Getting all your workouts in.

And then, after days of the scale consistently going down, you wake up one day and the scale goes back up.

WTF!?!?!?

If you’ve ever been in this situation, I know it can be frustrating and feels like you’ve taken a step backwards.

The truth is that the scale is going to fluctuate from day to day, and that’s completely normal. It doesn’t necessarily mean you gained fat overnight.

The scale doesn’t just measure body fat. It measures your total body weight, including muscle, bone, and all the fluids and content in your body at one time.

Before you give up on your diet completely, see if one of these reasons could be why the scale went up overnight.

Reason #1: You ate a lot of salt the day before

One of the most common reasons for waking up to a bigger number on the scale is from eating more salt than usual.

Restaurants often add a lot more salt to food than you probably eat at home. This is to make food taste better and keep you coming back!

If you weigh yourself the morning after eating out at a restaurant, you’ll probably find that you weigh more than the previous day.

Unless you ate an absolutely absurd amount of calories (3,500 calories over your maintenance calories, to be exact), most of the weight gain you’re seeing is probably because of the sodium in the restaurant food.

When you eat a lot of salty food, your body retains water to maintain its balance of water to sodium. 

In one study, subjects gained three pounds of body weight after going from a low sodium intake to a high sodium intake (1). 

Once your body can excrete the extra sodium through your kidneys, your weight will return to normal.

Reason #2: You ate more carbs than usual

If you eat more carbohydrates than usual, you’ll probably notice a bump in your weight the next day.

This doesn’t mean carbohydrates are fattening!

It’s actually pretty difficult for your body to store excess carbohydrates as body fat. Most of the fat we end up storing comes from dietary fat we eat. 

Research has shown that during periods of overfeeding, when overall calories are accounted for, excess dietary fat is more likely to be stored as body fat than excess carbohydrate (2).

Gaining body fat still comes down to an energy balance though. Even if you eat a low fat diet but too many calories, you will still gain body fat. You’ll just store a higher percentage of the fat you eat.

Okay, end of tangent. Back to why you gained weight from eating carbs..

When you consume carbs, your body will use some of them for energy and store the rest as glycogen in your muscle cells and liver, which can be used for energy later.

Studies have shown that you can increase your glycogen stores by about 500 grams before you store any excess as body fat (3).

For every gram of glycogen you store, you’ll also store 3-4 grams of water (4).

Let’s say you ate a ton of carbs over the weekend and increased your glycogen stores to the absolute maximum. 

You could see a scale increase of anywhere from 3-4.5 pounds the next morning, which would all be water weight!

This helps to explain why low carb or ketogenic diets seem to be so effective from the start. When you completely cut out carbs, you’ll drop a lot of water weight in the first few weeks. You’re not actually losing body fat, you’re just losing water weight.

When you compare diets that have the same amount of calories and protein, whether you eat low carb or high carb doesn’t matter. You’ll end up losing the same amount of body fat as long as you are in a calorie deficit.

Reason #3: You’re new to lifting weights

Speaking of glycogen..

If you’re new to lifting weights and you just started a training program, you’ll probably notice an increase in weight the first week or so.

It’s probably not new muscle, because that takes more time to build. Even complete beginners doing everything right would be making great progress putting on 1-2 pounds of muscle in their first month.

What’s likely happening is your body is storing more glycogen than normal, causing your weight to go up. Remember that for each gram of glycogen you store, you will also store 3-4 grams of water.

This is because glycogen is your body’s main source of energy when lifting weights. Glycogen is stored right in your muscle cells, so it’s readily available for use. 

Let’s say you perform a hard set of bulgarian split squats. Your body will use the glycogen stored in your quads and glutes to fuel that exercise. 

This lowers the amount of glycogen stored in your muscle cells, and triggers your body to replenish what’s been lost. 

This creates a supercompensation effect, and your body can store more glycogen in your muscle cells after exercise than before (5). This means an increase in weight because that extra glycogen is bringing water into your muscle cells.

Reason #4: You weighed in earlier than usual 

This one’s pretty straightforward.

If you usually wake up and weigh yourself around the same time every day (which you should be doing to accurately measure your weight loss.. more on that later..), waking up earlier won’t give your body as much time to process your last meal.

You didn’t gain pounds of fat overnight.

You’ll have more water and content in your gut than normal, which will show up as weight on the scale the next morning.

The same thing goes for if you eat dinner later than usual. You simply won’t have as much time to digest your last meal, so you’ll likely weigh in more the next day.

Reason #5: You’re more stressed than usual

Whether it’s a big deadline at work, an argument with your spouse, or someone cutting you off on your way to work this morning, everyone experiences periods of stress at some point or another.

When you’re stressed out, you release a hormone called cortisol.

In small doses, cortisol does a lot of good things, like help reduce inflammation, regulate your blood sugar levels, and control how your body uses protein, carbs and fats.

However, when you’re constantly stressed out, high levels of cortisol can have negative effects like cause high blood pressure and mess with your digestion.

Another issue with cortisol is that it can interfere with a hormone called aldosterone, which is responsible for helping maintain your body’s fluid balance.

When you’re under stress and your cortisol is elevated, you’re more likely to retain water. 

Being in too big a calorie deficit or being in a calorie deficit for too long can certainly be a form of stress. This is part of the reason reverse dieting can be so effective. By allowing yourself more calories, your cortisol levels can go down, causing you to lose water weight.

Dieters might see this reflected in their weekly weigh-ins. When you’re deep into a diet, you might notice that your weight will remain stable for a few days and then, whoosh! Suddenly you’re a few pounds lighter.

This is something known as the whoosh effect.

It’s not that you weren’t losing fat the whole time you were dieting. You were losing fat, but it was offset by the amount of water you were retaining.

Bonus reason (females only!)

Ladies, this one’s for you.

Around your time of the month, you’ll likely notice some weight gain. 

Most of this can be attributed to water retention.

This is because your estrogen levels go up right before you get your period, which throws off the balance between the two hormones estrogen and progesterone.

Estrogen levels rise in your body right before you get your period. The imbalance of estrogen to progesterone causes you to retain water (6). 

You can also thank the imbalance of these two hormones for the bloating you feel when you get your period.

Another reason you might notice your weight spike around your period is you tend to eat more salty foods that are high in carbohydrates, which as we learned earlier, will cause you to retain water.

Let’s be honest, you’re probably not craving chicken and broccoli while you’re on your period 😉

What should I do when the scale goes up?!?!

I get it, you’re frustrated because seeing the scale go back up after being consistent with your diet can be extremely discouraging.

The thing is, you don’t have to change anything when the scale goes up overnight.

Here’s why..

Hopefully you realize that none of the reasons the scale went up overnight are because you gained fat.

The only way to gain fat is to consistently eat too many calories. If you’re eating in a calorie deficit, you will lose fat over time, despite fluctuations in your scale weight. To find out how many calories you need for your goals, you can use my calorie calculator below.

Cal’s Calorie Calculator

First things first, you want to make sure you’re weighing yourself first thing in the morning on an empty stomach, after you’ve used the bathroom.

The scale will change throughout the day, because you’re eating and drinking which will change the scale.

Weighing yourself first thing in the morning will give you the most reliable results. If you sometimes weigh yourself in the morning, and then weigh yourself at night when you feel like it, your weights will be all over the place!

When looking at your scale weight, I highly recommend weighing yourself every day and comparing the average week to week rather than sporadically weighing yourself.

Comparing your average weight week to week will help account for days when your weight might spike for any of the reasons above.

You can see that if you take the average weight of both weeks, the person above lost a little over a pound. The spike in weight from 177.9 to 180.1 in week 2 could be for any of the reasons above, and is probably nothing to worry about.

If you only weigh yourself sporadically, you might miss the big picture. Let’s pretend that you only weigh yourself sporadically, and you just so happened to go out to eat the night before your weigh in.

It’s the exact same data as above, only now it looks like you didn’t make any progress at all!

The scale is also just one tool to measure your fat loss progress, and it doesn’t tell the whole picture. 

I also have my online clients take measurements every two weeks and progress photos once a month. 

Sometimes, you can be gaining muscle and losing fat at the same time. You might not see the scale change at all for a few weeks, which might lead you to think you’re not making any progress towards your goals. Taking measurements at your arms, waist, hips and thighs is a great way to see if that’s the case.

Progress pictures can also be a powerful tool in addition to measurements and scale weight averages. Taking pictures in the same or similar clothes, in the same location and using the same lighting can help make sure you’re on the right track.

Between looking at the combination of average weights, measurements and progress photos, you can get a full picture of what’s really going on. 

Wrapping up

The scale is going to go up and down, and that’s perfectly normal. 

It doesn’t mean that you’re not making progress or even that there’s something wrong with your plan!

You have to recognize that the scale is just a tool to measure progress. 

If you let what the scale says in the morning make or break your day, you’re going to have a very hard time staying consistent. 

Remember that fat loss takes time. For most people, one pound per week of fat loss is phenomenal progress! 

Be patient, measure your progress week to week instead of day to day, and stay on track. As long as you’re in a calorie deficit, you will lose fat.

If you have any questions, leave them below!