Blog Weight Loss Why Does My Weight Fluctuate 10 Lbs In A Day? 8 Reasons Why!

Why Does My Weight Fluctuate 10 Lbs In A Day? 8 Reasons Why!

why does my weight fluctuate 10 lbs in a day

Surprisingly, throughout the day your weight is different. If you have tried to record your weight throughout a day, you will concur that your weight fluctuates. Contrary to what most people think, daily weight fluctuation is normal. Why does my weight fluctuate 10 lbs in a day? There are a couple of reasons behind these fluctuations. Read on to learn more about how your weight fluctuates in a day and the reasons behind it.


Why Does My Weight Fluctuate 10 Lbs In A Day?

If you just started watching your weight, you will notice that you have different results in a day whenever you weigh yourself. Sometimes the numbers are high and sometimes they are what you expect to see. Here is why the scale tips to both extremes throughout the day:

Water Retention

Water retention is one of the major culprits of daily weight fluctuation. Here are some significant causes of water retention (2):

  • High Sodium Consumption

Sodium, or salt, is crucial in our bodies as it helps regulate blood pressure, transport nutrients, and balance water levels in the body. However, too much of it makes you retain more fluids, which leads to an increase in the number you see on the scale.

  • Dehydration

You are required to drink enough water every day to avoid getting dehydrated. Unfortunately, most people do not. Instead, some confuse thirst for hunger and end up eating instead of hydrating. 

When you do not drink enough water, your body stores water to avoid dehydration (2). Consequently, you retain water, which makes you scale budge throughout the day, depending on your water consumption behavior.

why does my weight fluctuate 10 lbs in a day  

Your Diet

Your weight is also highly influenced by whatever you eat throughout the day. Your energy balances between what you eat and what you burn, and it affects your weight. If you eat more than your body is burning, you gain weight, and sometimes the weight gain is instant (3). 

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Remember that weight loss is not easy. To lose one pound, Mayo Clinic states you will have to consume 500 fewer calories each day for a week or burn these extra calories through exercise (1). Contrary to what you may think, it is pretty hard.

To avoid weight gain caused by your diet, talk to your nutritionist to develop a meal plan that can help you maintain a healthy weight. Similarly, these professionals may also help you craft a weight loss diet plan if your goal is to lose weight.

Although there are numerous of such meal plans online, we do not advise you to start them without seeking professional help.

Read More: The 3-Day Fruit Diet For Weight Loss: Pros, Cons, And What To Expect

How You Weigh Yourself

Yes, you heard it right. The manner in which you weigh yourself may also lead to your weight fluctuation throughout the day. There are several factors you need to consider when weighing yourself. Some of these include your outfit, weight distribution on your feet, and where you place your scale (3).

To begin with, you must always place your scale on a hard surface. Also, when weighing yourself, dress in light clothing and do the same every time you step on the scale. In addition, stand on both feet and make sure your weight is evenly distributed on both feet.

why does my weight fluctuate 10 lbs in a day

When You Weigh Yourself

Besides how you weigh yourself, the times in the day when you weigh yourself also accounts for the weight fluctuation. You will always get different results when you weigh yourself in the morning, afternoon, and evening.

Experts suggest you weigh yourself in the morning for the most accurate result (3). This is because during this time, you probably have not had anything to eat or drink. However, during the day, your scale will teter because as your day continues you eat and drink. Your scale will read higher after you have a big meal. So, brace yourself for these differences.

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The Frequency Of Your Bathroom Breaks

Believe it or not, your weight fluctuation is also affected by the number of times you visit the washroom. If you had a big meal and happened to weigh yourself, you might weigh more. This is caused by the fecal weight of the food waste you haven’t yet excreted (3).

Similarly, if you had a lot of fluid to drink, you will report increased weight. It is because of urine buildup. On the other hand, if you just emptied your bladder or bowels or have lost fluid due to diarrhea or vomiting and weigh yourself, you will see a lower number (3).


Exercising is crucial because it reduces our risk of various conditions, improves our overall health, and promotes weight loss. According to WebMD, some athletes are reported to drop 6% to 10% of their body weight after one workout due to loss of fluid from sweating (3).

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why does my weight fluctuate 10 lbs in a day


There are several medications responsible for weight fluctuation. Some of them include:

  • Antidepressants 

One of the side effects of antidepressants is weight gain. You may experience weight gain after taking these medications for a while (4). Do not stop this drug treatment if you suspect it is responsible for your weight gain. Instead, talk to your doctor and let them know of your concerns. They may recommend another drug alternative or other strategies to counter the negative effects.

  • Steroids

Some anti-inflammatory steroid medications like prednisone result in weight gain (4). They tend to cause water retention that results in water weight. Similarly, they also increase your appetite which makes you consume more calories.

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Despite this effect, experts do not advise you to suddenly stop taking steroids if you have been taking them. This may lead to more severe problems, which is why you need to check with your doctor first.

  • Antipsychotic Drugs

These refer to medications used to treat psychiatric mental disorders like bipolar disorder and schizophrenia (4). They may stimulate appetite, which makes one eat more food, and possibly consume more calories than required.

  • Birth Control Pills

There is a common belief among women that birth control pills cause weight gain. Before you blame the pill, WebMD is quick to note that these drugs are not proven to cause long-term weight gain (4). However, some women may experience short-term weight gain due to fluid retention. Talk to your doctor if you are concerned about your birth control pills resulting in weight gain.

Other drugs that may result in weight gain include medications used to treat diabetes, migraines, high blood pressure, and seizures (4).

Read More: Keto Workout Plan: How To Exercise On A Low-Carb Diet

meal plan

Various Health Conditions

Some health conditions will also result in unexpected weight change. Some will suppress your appetite while others will lead to water retention, but could tip your scale at the end of the day. Take a look at some of these conditions:

  • Polycystic Ovary Syndrome (PCOS)

One of the many health conditions that results in female weight gain is PCOS. PCOS is a hormonal problem among women in their childbearing ages where the women grow many small cysts on their ovaries (4).

The condition leads to hormonal imbalances, which leads to several side effects. These include weight gain, irregular menstruation cycles, hair loss, excessive hair on the chest, back, or abdomen, and acne (5). 

Unfortunately, there is no cure for this condition. Nevertheless, doctors do recommend women with PCOS to adopt lifestyle changes like exercising and eating a healthy diet to ease the symptoms (5).

  • Hypothyroidism

Hypothyroidism refers to a condition where your thyroid gland doesn’t produce enough thyroid hormone. If your thyroid does not make enough thyroid hormone, you feel weak, tired, cold, and end up gaining weight (4).

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Similarly, WebMD acknowledges that your metabolism slows down, meaning you are burning calories at a slower rate than normal. A slow metabolism results in weight gain because you are burning fewer calories than you are consuming. The only way you can reverse weight gain caused by hypothyroidism is by getting treated for it. 

  • Kidney Problems

Sudden weight gain may sadly reflect kidney problems if accompanied by other symptoms of kidney diseases. If your kidneys are not operating efficiently, your body will retain water, which contributes to weight gain. 

Kidney problems can lead to water retention because the kidneys are responsible for removing fluids and excess water from the body (5). The other symptoms you should watch for that indicate kidney problems include fatigue, less urinating, urine looking foamy, muscle cramps, itchiness and joint pain (5).

If you tend to let yourself off the hook, raise the white flag when things get tougher than you expected, send yourself on an unconscious binge-eating trip – BetterMe app is here to help you leave all of these sabotaging habits in the past!

why does my weight fluctuate 10 lbs in a day

  • Ovarian Cancer

Sudden and unexplained weight gain and bloating could be attributed to ovarian cancer. However, if this is the case it would be accompanied by other symptoms of ovarian cancer. Some of these include sleeping difficulties, pelvis or abdomen pain, frequent urge to urinate, indigestion, unusual menstrual cycle, and loss of appetite (5).

  • Cushing’s Syndrome

Cushing’s syndrome is another condition that leads to weight gain, particularly in the face, abdomen, upper back, and neck (5). The condition occurs when your body produces too much cortisol over an extensive duration (5).

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Cortisol is the hormone that offers your body the ability to respond to stress. It is very rare for you to develop this disease without an external trigger. However, it is a major side effect of taking glucocorticoids. These are drugs used to treat asthma, systemic lupus erythematosus, and rheumatoid arthritis (5).

When To See A Doctor

Some causes of weight loss or weight gain are not alarming. Your weight naturally varies throughout the day, and weight fluctuations are affected by how and when you weigh yourself. In such cases, there is no need to see a doctor. All you have to do is re-adjust and learn when and how to weigh yourself for accurate results.

However, contact your doctor if you experience rapid and unintentional weight changes without any obvious cause. They will carry out a physical examination and blood tests to determine if there is an underlying health condition causing the weight changes.

The Bottom Line

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.



This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on for decision-making. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. Counting calories: Get back to weight-loss basics (2020,
  2. How much does weight fluctuate? (2020,
  3. Reasons Your Weight Changes Throughout the Day (2019,
  4. Surprising Reasons You’re Gaining Weight (2020,
  5. What causes rapid weight gain? (2019,
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