Ever feel like you do everything right when it comes to weight loss but for some reason, the scale jumps up? Even after a “perfect day” of eating healthy and exercising, your weight doesn’t move the way you want it to?

It’s common to want to throw in the towel when your weight doesn’t drop right away. Does the number on the scale in the morning determine how you feel about yourself for the day? How motivated you are? Does it control how the first part of your day will go and affect your eating and exercise habits for the day?

We tend to forget that number is highly variable- many things can influence the scale.

If you have an obsession with the scale, I want to share with you 9 reasons why your weight fluctuates as well as how to accurately measure your progress to help you reach your physique goals!

#1 Water Intake

This may be the most obvious reason why the scale fluctuates from day to day, but what actually influences fluid shifts in our body besides drinking and sweating?

Sodium and glycogen cause us to hold onto water while caffeine, alcohol, and diuretics increase fluid excretion. Workouts, sleep, supplements, muscle soreness, sunburns, and hormonal shifts also affect how much fluid we retain. More on this later!

#2 Sodium

Dietary sodium is crucial for health, especially if you’re exercising and/or working outdoors. However, water follows salt, which explains why you may feel bloated or notice a weight increase after dining out. Even if you ordered something healthy, restaurant establishments typically use a lot more salt in their cooking.

Take Chipotle as an example. A nutritious vegetarian bowl with brown rice, black beans, pico de gallo, corn, and guac has 1650 mg of sodium. The recommendation for the general population is to consume no more than 2,300 mg per day.

Does this mean you should never eat Chipotle? Absolutely not (especially because they have more nutritious options compared to many fast food establishments). Just don’t get freaked out by a slight increase in weight. Balance it out by eating whole, minimally processed foods for the rest of the day and drinking plenty of fluid.

Tip: If you struggle with drinking enough water, buy a large, BPA-free water bottle and a large nozzle (like this one) and aim for at least 32 ounces before lunch and 32 ounces after.

#3 Sleep

Ever notice how you may weigh less on Sunday morning, even when you’ve indulged a bit on Saturday? If so, compare how much you sleep on weekends compared to weekdays.

Many people use weekends to sleep in, giving the body extra time to shift fluid from our body cells to our bloodstream. From there, fluid is sent to our kidneys so it can be excreted when we urinate the next morning. Therefore, we’re losing additional ounces in water weight.

While it’s immediate water weight loss, catching enough Z’s is linked to fat loss for other reasons:

Aim for 7-9 hours of restful sleep per night as part of your weight loss and health goals. Avoid using screens 1-2 hours before bed and consuming caffeine after noon if you are having trouble falling asleep. Keep in mind that teas and pre-workout supplements often have caffeine as well. If you’re looking for a workout boost without caffeine, read our pre-workout post.

#4 Fiber

Many of our clients feel discouraged when they notice water retention after increasing their vegetable and fiber intake. Since fiber is indigestible, introducing large amounts at one time may make you feel bloated or gassy.

Since fiber is a key component for weight loss, blood sugar control, heart, and digestive health, don’t let initial water weight keep you from eating it! Instead, slowly increase your intake by 2-5g per day. Women should aim for at least 25 grams per day while men require at least 38 grams.

It’s also important to drink enough fluid. While it may seem counterintuitive, drinking more water actually helps reduce bloating and helps ease fiber digestion!

Not drinking enough water is the #1 cause of constipation.

#5 Glycogen

Glycogen can be described stored energy (glucose). Our bodies store glycogen primarily in the liver, skeletal muscle tissue, and fat cells. We pull from these stores throughout the day as we move, breath, exercise, etc. Though dietary fat and some protein is converted to glucose/energy, most of our glycogen stores are from carbohydrate.

Here’s the kicker- for every 1 gram of glycogen, our bodies retain 2-3 grams water! This can explain why people who follow a ketogenic or very low carb eating plan may experience rapid weight loss in the initial phases of the diet.

Your body holds on to this water for good reasons! A well-hydrated muscle tissue is a healthy tissue- water transports vital nutrients to the cells to aid in cellular functions such as muscle synthesis.

So don’t fret if you notice the scale jump up days after a high carb meal- it’s likely not related to body fat, it’s just part of how your body utilizes carbohydrate.

#6 Creatine

The supplement creatine can also cause water retention. This water retention is ‘intra-cellular,’ meaning it is stored within in the cell itself rather than underneath the skin. This explains the weight gained after taking a creatine supplement, even though you may not experience any side effects such as abdominal bloating.

For more info about creatine, check out our post Supplements that Work: Creatine.

#7 Inflammation & Muscle Soreness

Ever crush a workout only to be dismantled by a weight increase the following day?

Exercise breaks down muscle tissue, sending the signal to your body there is damage. Therefore, it holds onto water and targets inflamed tissues so help heal & soothe swelling.

In case you need another reason to wear sunscreen, this explains why even a sunburn can cause water retention!

#8 Hormonal Shifts

Many women experience water retention about a week before their menstrual cycle due to shifts in the sex hormones progesterone and estrogen.

If you struggle with bloating before your period, a low sodium diet, adequate fiber, and plenty of water can help ease the symptoms. Our PCOS & Gut Health post is full of helpful digestive health & diet tips.

#9 Muscle Growth!

One exciting reason the scale isn’t dropping may be due to an increase in lean muscle mass, particularly if you are exercising regularly!

While this shift is not instantaneous, muscle growth slows weight loss but improves your physique and boosts your metabolism. The best way to measure fat loss and total lean body mass is by getting a Dexa Scan. If you’re local to Orlando, get tested at DexaFit Orlando.

Monitoring Weight Loss

So we’ve learned the scale isn’t the most consistent form of measuring progress but for some, it is an accountability tool. If you choose to use the scale to monitor weight loss, weigh under consistent conditions (i.e, same scale, time, & clothes; empty bladder; unshowered). Record your weight 4-7x per week and average those numbers. You can track your weekly average weight and identify a trend. More than 1% body weight lost in one week is likely influenced by water.

If you notice that jumping on the scale every morning is continuously making you question yourself or putting you in a bad mood, PUT IT AWAY!

You can also measure progress with….

Struggling with weight loss? Meet with one of our registered dietitians to develop an individualized game plan to meeting your nutrition, diet, or weight loss goals.

Post by Kait Richardson, RDN, LD. Read more about the dietitians at Nutrition Awareness here.

Disclaimer: This article is intended for informational purposes only. I am not a medical doctor and recommendations provided should not take the place of medical advice or treatment.

Some blog posts may contain one or more affiliate links. I was not paid by any of the companies above to review their products. All opinions are my own.


CDC Sodium Recommendations

Chipotle Nutrition Calculator

Circadian Rhythms and Sleep

Sleep & Fat Loss

Sleep & Weight Loss (LBM vs Fat)

Water and Glycogen

Kait Richardson is a registered dietitian nutritionist in Orlando, FL. She is a partner at a private practice, Nutrition Awareness, where she helps frustrated yo-yo dieters reach their health goals using 1:1 nutrition coaching. She is the co-host of the Nutrition Awareness Podcast.