Why Does Weight Fluctuate From Morning to Night? | Livestrong.com (2023)

Why Does Weight Fluctuate From Morning to Night? | Livestrong.com (1)

It's typical for a person's weight to change throughout the course of the day.

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If you're watching your weight, it's tempting to step on the scale several times a day. But resist the urge — these frequent checks can be frustrating and misleading, as weight naturally fluctuates throughout the day. So if you're wondering why you weigh more at night, rest assured that's normal.


Indeed, there's usually a several-pound difference in your weight morning versus night (more on that soon). Here's everything you need to know about daily weight changes.

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How Much Does Your Weight Fluctuate From Morning to Night?

Weight-loss statistics show on average, daily weight can fluctuate from 1 to 2 kilograms (2.2 to 4.4 pounds), per a July 2017 article in Physiological Reports. So if you notice you do weigh more at night, that's normal: Body weight is typically a bit lower in the morning because you eat less food and fluids overnight and lose water through sweat and breathing, per the American Physiological Society.


But not everyone is the same, and above-average weight fluctuations can occur in people with more muscle mass, or related to changes in diet and exercise. So if you're wondering why you weigh less at night and more in the morning, these may be the reasons why.

Water makes up around 75 percent of muscle mass, according to an August 2019 review in Nutrients. So people with higher amounts of muscle mass could experience weight fluctuations of several pounds per day as they undergo changes in muscle mass.


What's more, runners can lose several pounds of water weight after a several-mile run, and fluid replacement is essential for safety and performance, according to the Academy of Nutrition and Dietetics.

Drastic changes to diet can also affect how much more you weigh at night by causing weight loss or gain that exceeds the daily average of 2.2 to 4.4 pounds, per the Mayo Clinic.


For example, if you nearly eliminate carbohydrate foods from your diet, the body uses glycogen stores for energy — which can lead to weight loss of 10 or more pounds in a week and may influence how much heavier you weigh at night.

Resuming a diet that includes carbohydrate foods after a brief fast or low-carb diet can also lead to several pounds of weight gain, as the glycogen stores are restored.



What Causes Weight Fluctuation?

Daily changes in weight are normal, although shifts in body water — not body fat — explain most of the daily fluctuations, according to a July 2017 article in Physiological Reports. Because an average of 60 percent of an adult's body weight comes from water, per the Academy of Nutrition and Dietetics, even small losses of water can show up as weight loss on the scale.


Here are some of the key factors that could cause the number on the scale to shift from a.m. to p.m.

Fluctuating Fluids

The water in your body shifts from morning to night. Body water is lost through sweat, respiration, urination and with bowel movements, according to Harvard Health Publishing.


Exercising and being in hot temperatures cause an even greater loss of body water. Illness, including symptoms of diarrhea, fever and vomiting, can also cause water loss — and a temporary drop in weight, according to the Merck Manual.

Body water is replenished by drinking beverages and eating water-containing foods.

Related Reading

How to Tell if Weight Is Water Weight or Fat Weight

The Glycogen Factor

The loss or gain of glycogen — the storage form of glucose found in the liver and muscles — is another cause of short-term weight fluctuations. Glycogen is stored with up to 3 or 4 parts water, so when this energy source is broken down, the body also loses extra water — and weight, according to the article in ​Physiological Reports​.


Glycogen can be quickly depleted — and weight can be lost — from extended exercise, or as a result of very low-carbohydrate or fasting diets, per an April 2018 article in Nutrition Reviews.


On the other hand, someone who has depleted glycogen stores from dieting or exercise can regain weight after eating carbohydrate foods and glycogen stores are built back up.

Intestinal Contents

This factor makes intuitive sense: Your weight will temporarily change when you eat or drink because your body now contains what you ate. Just drinking 16 ounces of water can spike your weight by about a pound. This temporary weight of food and liquids stays with you as your body digests and absorbs water and nutrients, until it sends waste out of the body via urine and stool.

Even as stool is in your intestines, it adds to your weight. The average daily weight of stool in humans is 128 grams — or 0.28 pounds — according to September 2015 research in Critical Reviews in Environmental Science and Technology.

But rest assured, these weight changes are temporary and when you urinate or have a bowel movement, your weight will go down a bit.

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3 Ways Your Weight and Your Poop Are Connected

Other Factors

Other factors can explain short-term weight fluctuations. For example, if you are dehydrated, your weight will be lower. If you tend to retain water, a condition known as edema, you can gain weight.

Edema can occur in pregnancy, in premenstrual syndrome, or due to other medical conditions such as liver, kidney or heart disease, per the Mayo Clinic. Taking in too much sodium, a mineral important for water balance, can worsen edema, according to Harvard Health Publishing.

Certain medications can also lead to water retention, per the Mayo Clinic. Steroids and some blood pressure and diabetes medicines are common types of drugs that can cause puffiness or swelling.


Alternatively, diuretics or "water pills" can lead to weight loss, as these medications remove extra body fluid. Taking any of these drugs can cause weight fluctuations between morning and night.

When to Weigh Yourself for Accurate Weight

If you are tracking your weight, you may be more interested in changes to muscle and fat weight instead of the temporary fluctuations from fluids, foods and intestinal contents. Changes to fat and muscle mass occur more gradually, as these are influenced by the calories and nutrients in your diet along with your physical activity.

To assess these weight changes, there's no hard and fast rule for when you should weigh yourself. Instead, be consistent: Weigh yourself at regular intervals (like once a week) at the same time (like morning), on the same scale, wearing similar clothing, according to the Cleveland Clinic.

That way, your weigh-ins will more accurately reflect your routine rather than providing random snapshots of your weight fluctuations throughout the week, as it's possible to gain weight in an hour without eating or drinking due to factors like an inaccurate scale, wearing heavy clothing or fluid retention.

Related Reading

2 Reasons Why Weighing Yourself Daily Can Help You Lose Weight — and 2 Reasons It Might Not

Weight Loss and Weight Fluctuation FAQs

You asked, we answered: Here are some common questions about daily weight changes.

1. Do You Weigh Less After You Poop?

Bowel movements are comprised of all of the waste material left over from the digestive process, according to the U.S. National Library of Medicine. And expelling that waste from your body will result in small amounts of temporary weight loss — 0.28 pounds on average, per the ​Critical Reviews in Environmental Science and Technology​ research.

However, more frequent bowel movements aren't a weight-loss strategy. Instead, you need to lose weight sustainably by burning excess fat through a combination of nutritious eating and regular exercise, according to the Mayo Clinic.


2. Why Do I Weigh Less an Hour After Waking Up?

Your body processes excess fluid overnight, which you eliminate in the morning when you pee, according to Johns Hopkins Medicine. Shedding this water weight is often the reason why you weigh less in the morning or soon after waking up.

The same goes for morning bowel movements, which can further contribute to a lower weight early in the day.

3. Why Do I Weigh More But Look Thinner?

Your body size may get smaller while your weight goes up if you're becoming more muscular.

For instance, activities like strength training can help you burn fat while building lean muscle mass, according to the Mayo Clinic. And because muscle is more compact than fat, it takes up less space on your frame even while increasing your weight, per the Baylor College of Medicine.

4. Is It Possible to Lose Weight But Not Show on Scales?

Similarly, if you're visibly losing weight but the number on the scale isn't budging, that's likely because you're burning fat while also gaining lean muscle mass, according to the Baylor College of Medicine.

5. Why Do I Weigh More After Exercising?

If you're new to an exercise program, your body retains extra fluid to help repair micro-tears in your muscle, according to the Cleveland Clinic. As a result, you may temporarily weigh more after exercising until your muscles heal and your body adapts to the activity.

When to Talk to Your Doctor

Weight changes that are lower or higher than the average of 2.2 to 4.4 pounds a day could be related to medications or health conditions.

Let your doctor know if you are experiencing weight fluctuations outside of the average range or outside of the range recommended by your doctor, particularly if you are being treated for any medical conditions or if you are taking any prescription medication.




Why does my weight fluctuate so much from morning to night? ›

Why does my weight fluctuate so much? “Everyone's weight fluctuates throughout the day, and especially from morning to night,” says dietitian Anne Danahy, MS, RDN. “The average change is 2 to 5 pounds, and it's due to fluid shifts throughout the day.” If you see fluctuations of less than 5 pounds, you needn't worry.

Why does my weight fluctuate 5 lbs from morning to night? ›

Daily weight fluctuation is normal. The average adult's weight fluctuates up to 5 or 6 pounds per day. It all comes down to what and when you eat, drink, exercise, and even sleep. Read on to learn more about how these factors affect the scale and when to weigh yourself for the most accurate results.

Why does weight fluctuate from day to day? ›

Why Does Weight Fluctuate? Factors like sodium and carbohydrate intake, exercise, food intake, bowel patterns, a person's menstrual cycle, medications, and alcohol can all contribute to daily swings in the number on the scale.

Is your true weight morning or night? ›

You should step on the scale first thing in the morning. That's when you'll get your most accurate weight because your body has had the overnight hours to digest and process whatever you ate and drank the day before. And you should try to turn that step into a regular part of your routine.

How did I gain 4 pounds overnight? ›

"Food eaten at night is more often stored as fat because we tend to be less active, so we increase fat storage at that time, especially depending on the composition of the food you ate later in the evening," says Dr. Covington.

How did I gain 10 lbs overnight? ›

It's most likely your overnight weight gain came from sodium and carbs. However, if you're sensitive, intolerant or allergic to inflammatory foods, eliminating them is the only way to stop the cycle. Corn, soy, dairy products, wheat, and gluten are the top foods affecting inflammation.

Why did I gain 10 pounds in 2 days? ›

Why Does My Weight Fluctuate So Much? Since many people can't eat enough in a day or two to actually gain 5 or 10 pounds, if you notice a dramatic increase on the scale, chances are it's due to water, says Anita Petruzzelli, M.D., owner and medical director of BodyLogicMD.

Why did I gain 5 pounds in one night? ›

You're Dehydrated

Dehydration causes your body to retain excess water, which can lead to 5 pounds of weight gain overnight (5). When you feel thirsty and drink a lot of fluid at once, you'll absorb the extra fluid quickly and it shows up on the scale within 24 hours.

Can your weight fluctuate 10 pounds in a day? ›

The reality is, small changes in weight are completely normal and expected. Body weight can shift throughout the week and even during the day. In fact, an average adult can lose or gain two to eight pounds over the course of a few days.

Does drinking water help you lose weight? ›

Water can be really helpful for weight loss. It is 100% calorie-free, helps you burn more calories and may even suppress your appetite if consumed before meals. The benefits are even greater when you replace sugary beverages with water. It is a very easy way to cut back on sugar and calories.

Why do I weigh more after poop? ›

If you were to weigh yourself before and after pooping, the weight change on the scale would reflect the weight of the stool, which also contains protein, undigested fat, bacteria, and undigested food residues. Of course (and unfortunately), this doesn't mean you've lost weight.

When should you not weigh yourself? ›

A person should also avoid weighing themselves on the days before their period. During the week leading up to menstruation, hormones cause fluctuations in weight. These fluctuations can temporarily affect weight measurements.

How many lbs do you take off for clothes? ›

Men, it seems, prefer to swathe themselves in heavier garments while women tend to adorn themselves more lightly. Men can lop off nearly 2.5 lbs to account for their clothing while women can only subtract around 2. And this holds true, unfortunately, no matter what the weather outside.

What part of the day do you weigh the most? ›

Typically, you weigh more after eating. You'll usually weigh less after strenuous physical activity because of the water you've lost through sweating. This is why one of the best times to weigh yourself is in the morning before you've eaten or exercised.

Is morning Skinny your actual weight? ›

According to a study done by Live Strong, “Not only do you look slimmer in the morning, but you actually weigh less, too.” While good night's sleep alone isn't enough to make you lose major pounds, you do burn calories while you sleep. “When we sleep at night, our body enters a fasting period,” said Dr.

Why do I keep gaining weight even though I barely eat? ›

Many factors can contribute to unintentional weight gain. Poor sleep, sedentary activities, and eating too many processed or sugary foods are just some of the habits that may increase your risk of weight gain.

Why am I gaining weight when I'm eating less and working out? ›

You're gaining muscle. The scale might be stuck because you're building up your biceps and glutes—and that's a good thing. The number on the scale is less important than the breakdown of how much water, muscle, and fat are in your body, Jovanovic says.

What is the most weight you can gain overnight? ›

Fitness experts, dieticians, and nutritionists, and research would tell you that one cannot gain weight overnight, because to gain one pound of fat, you would have to eat an excess of about 3500 calories in a single day (after subtracting the requisite calories required to run regular bodily functions, read about “ ...

What foods cause weight gain overnight? ›

Sodium causes the body to retain water, so if you eat a salty meal or snack, you can be puffier and heavier overnight.

Will 3 days of overeating make me gain weight? ›

Many people complain that they gain weight around the holidays, but you'll be happy to know that you can't really gain weight from a single meal or day of overeating.

How to speed up metabolism? ›

5 ways to boost metabolism
  1. Exercise more. Add interval training to your cardio routine and burn more calories in less time. ...
  2. Weight train. Add muscle mass to your body and you can burn more calories at rest. ...
  3. Don't skip meals, especially breakfast. ...
  4. Eat fat-burning foods. ...
  5. Get a good night's sleep every night.

What food makes you gain weight the fastest? ›

  • Rice. Rice is high in carbohydrates. ...
  • Whole grain bread. Whole grain bread contains complex carbohydrates and is higher in protein than white bread. ...
  • Whole grain cereals. Whole grain cereals include foods such as oats, wheat, barley, and rice. ...
  • Dried fruits. ...
  • Dark chocolate. ...
  • Other starches.
Sep 9, 2022

What causes rapid weight gain in females? ›

This may be due to menstruation, heart or kidney failure, preeclampsia, or medicines you take. A rapid weight gain may be a sign of dangerous fluid retention. If you quit smoking, you might gain weight. Most people who quit smoking gain 4 to 10 pounds (2 to 4.5 kilograms) in the first 6 months after quitting.

How often should you weigh yourself? ›

So, how often should you weigh yourself? Expert opinions vary. A study presented by the American Heart Association News found that daily weigh-ins help with accountability. At the same time, Healthline recommends weekly weigh-ins as long as it doesn't trigger anxiety or disordered eating.

Do you weigh more after a shower? ›

“Your skin is the largest organ in the body and absorbs fluid easily,” says Dr. Keith Kantor, a leading nutritionist and CEO of the Nutritional Addiction Mitigation Eating and Drinking (NAMED) program. “After a swim or a shower, your body can absorb 1 to 3 cups of water, increasing your true weight by a few pounds.”

How long does it take to lose water weight? ›

It takes about two days to lose one to three pounds of water weight. But how fast excess water leaves the body can depend on diet and physical activity. The healthier your diet and the more physically active you are, the faster you can get rid of excess water.

How long does it take for water weight to go away? ›

The length of time that it takes to lose water weight depends on how much water you're retaining, the cause of the water weight gain, and the action taken to lose it. If you have one high-sodium meal and then return to normal, healthy dietary habits, you'll likely return to your normal weight in 1-2 days.

Will I gain weight if I overeat one day? ›

Overeating one day will not have much impact on your weight, but it will surely leave you feeling bloated. You can have an extra slice of your favorite cheesecake occasionally, but do not make this your habit. The next day, return to your fitness routine and everything will be fine.

How much weight fluctuation is too much? ›

A. The weight of your body can fluctuate throughout the week and even during the day. In fact, over a few days, a typical adult can lose or gain two to eight pounds. Weight fluctuation follows a weekly pattern, with higher numbers on the scale at the start of the week and lower values at the end.

Why is my weight fluctuating so drastically? ›

“So, weight can fluctuate with the amount of food you eat and how much is still in your colon based on how often you have bowel movements, how much you urinate, the amount of salt or sodium in your diet—water follows sodium so more sodium the more water you hold on to—and how well hydrated or dehydrated you are.”

What should I drink before bed to lose weight? ›

You can drink ginger tea, cinnamon tea, fenugreek water, chamomile tea, or turmeric milk before bed as they may help improve your metabolism. Yes, drinking lemon water before bed may help burn fat at night.

What is the water trick to lose weight? ›

Hydration may support weight loss

One study found that adults with excess weight or obesity who drank 2.1 cups (500 mL) of water 30 minutes before a meal ate 13% less food than adults who didn't drink fluids before eating ( 2 ).

How many pounds of poop can your colon hold? ›

The average person's colon can often hold 8 to 25 lbs of accumulated fecal matter.

Where does fat go when you lose weight? ›

As your body metabolizes fat, fatty acid molecules are released into the bloodstream and travel to the heart, lungs, and muscles, which break them apart and use the energy stored in their chemical bonds. The pounds you shed are essentially the byproducts of that process.

Should I eat once a day? ›

Safety Concerns. For most people, there are no serious dangers involved in eating one meal a day, other than the discomforts of feeling hungry. That said, there are some risks for people with cardiovascular disease or diabetes. Eating one meal a day can increase your blood pressure and cholesterol.

At what point is weight unhealthy? ›

If your BMI is less than 18.5, it falls within the underweight range. If your BMI is 18.5 to 24.9, it falls within the Healthy Weight range. If your BMI is 25.0 to 29.9, it falls within the overweight range. If your BMI is 30.0 or higher, it falls within the obese range.

Should I pee before I weigh myself? ›

Follow these steps below to get the most accurate weight possible: • Weigh yourself at the same time each morning: after you urinate but before you eat or drink. Use the same scale every day. Place the scale on a hard, flat surface without carpet.

Why do I weigh more than I look? ›

Muscle is denser than fat, and as it is more compact within your body, as you gain muscle mass, you end up looking thinner, no matter your physical weight. So, if you've been doing a lot of strength training lately, it's likely this is the reason that you're looking fantastic but not dropping those numbers.

Why does my weight fluctuate 10 lbs in a day? ›

Why does my weight fluctuate 10 lbs in a day? There are several reasons behind these fluctuations. They range from the medications you are taking, when and how you weigh yourself, your dietary patterns, existing medical conditions, water retention and the frequency of your bathroom breaks.

How did I gain 2 pounds overnight? ›

In some people, especially those who have been dieting or fasting, a meal high in carbohydrates, such as pasta or rice, can be stored as glycogen. Glycogen is stored with water, which causes an individual to gain water weight very quickly – as much as 2 pounds overnight.

How did I gain 10 pounds in a week? ›

One of the many possible culprits behind rapid weight gain in a week or weight gain over time is a slow metabolism. This is caused by numerous things, some of which cannot be controlled. These include factors like your genes, age, and hormones (1). Others include an overly restrictive diet, or specific medications.

How do I stop my weight from fluctuating? ›

If you want to minimize this kind of fluctuation, you can limit water retention by avoiding processed food—but know that these fluctuations don't reflect a gain in fat. Limiting your sodium intake—and instead eating foods that are rich in potassium and magnesium—can also minimize daily weight changes.

Why do I weigh more after I poop? ›

If you were to weigh yourself before and after pooping, the weight change on the scale would reflect the weight of the stool, which also contains protein, undigested fat, bacteria, and undigested food residues. Of course (and unfortunately), this doesn't mean you've lost weight.

Why am I putting on weight when I am eating less? ›

When cortisol goes up, our bodies may hold onto more water, which means we feel “softer” and “less lean” than we actually are. This water retention can mask the fat loss that is occurring, making it seem like we aren't losing fat and weight, when in fact we are.

Why am I eating less and gaining weight? ›

While a general rule of thumb is that eating less causes you to lose weight, there are reasons why you might be packing on the pounds even though your diet is sparse. The types of foods you eat, your workout regimen and certain lifestyle factors could all be to blame if you're dieting but the scale is rising.


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