Why don’t you weigh less after a poop?

It’s a common experience – you sit down on the toilet, do your business, and get up expecting the scale to show a lower number. But more often than not, the number hasn’t budged. So what gives? Why don’t you weigh less after taking a poop?

Quick Answers

Here are some quick answers to this question:

  • The weight of poop accounts for a small portion of your total body weight.
  • Your body constantly fluctuates in weight due to water loss, fluid intake, undigested food, etc.
  • Scales are not precise enough to register small changes in body weight from a bowel movement.

In other words, the amount of poop itself does not make up a significant portion of your overall body weight. And normal fluctuations in hydration, stomach contents, etc. can obscure any small change that pooping might have caused. So in most cases, the difference is too small for the scale to pick up.

Why Poop Doesn’t Seem to Change Your Weight

There are a few key reasons why you don’t see the number on the scale drop after pooping:

Poop Doesn’t Account for Much Weight

While poop certainly has mass and contributes to your overall weight, it actually makes up a very small percentage of your total body weight. The average person poops about 1 pound per day. Compare that to overall body weight – let’s say 150 pounds – and daily poop only accounts for 0.67% of total body weight. Losing such a small proportion of overall weight isn’t likely to make the scale budge.

Your Body Weight Fluctuates

Our bodies are constantly gaining and losing small amounts of weight on any given day. Here are some of the factors that impact daily weight fluctuation:

  • Water loss – You lose water when you sweat, urinate, and even breathe. This can easily cause your weight to drop a couple pounds throughout the day.
  • Fluid intake – Drinking a few glasses of water or other fluids adds weight back.
  • Undigested food – Food that sits in your stomach and intestines adds weight.
  • Salt intake – Consuming salt causes your body to retain more water, potentially increasing weight temporarily.
  • Bowl movements – Pooping and peeing remove waste from your body, decreasing weight.

These small fluctuations happen on top of any change from pooping. So even if pooping lowered your weight slightly, drinking a glass of water right afterwards could bring your weight right back up.

Scales Aren’t Precise

Bathroom scales are useful tools, but they aren’t extremely precise. Many digital bathroom scales only round to the nearest 0.2 lbs. This means the scale wouldn’t detect a change of just a few ounces in body weight – it would still show the same number.

So unless your bowel movement resulted in significant weight loss exceeding the precision capabilities of your scale, the number on the scale would likely stay unchanged.

How Much Weight Is Lost During Pooping

Okay, so we’ve established that poop doesn’t usually result in a lower number on the scale. But exactly how much weight does poop account for? Here’s a look at the typical weight of poop:

  • Average poop weighs around 1 pound.
  • Larger poops may weigh up to 2 pounds.
  • Diarrhea results in less solid poop, so it may only weigh a few ounces.
  • Most people poop between 3 times per week and 3 times per day.
  • This results in a typical daily poop weight between 1/3 pound and 1 pound.

As a fraction of overall body weight, poop accounts for very little weight loss. But over the course of a year, pooping can add up to several pounds of eliminated waste! It may not cause the numbers on the scale to go down, but pooping is still important for removing waste from the body.

When Will Poop Make You Lose Weight?

While a normal bowel movement may not result in measurable weight loss, there are some instances where pooping does cause the scale weight to go down:

Severe Constipation

In cases of severe constipation, people may go multiple days without a bowel movement. Once constipation is relieved, they may poop significantly more than usual. Let’s say someone hasn’t pooped for 4 days and then poops 4 pounds at once. This could cause the scale weight to go down by a couple pounds.

Food Poisoning and Diarrhea

Food poisoning or diarrhea can both result in large volumes of liquidy poop. Having frequent bouts of diarrhea could lead to observable decreases in scale weight over the course of a day or two.

Taking Laxatives

Some people take laxatives before a weigh-in for sports, wrestling, or other activities with weight classes. The laxatives stimulate bowel movements and eliminate additional waste, possibly decreasing weight a couple pounds temporarily.

In all of these situations involving large poop volumes, the weight loss is still temporary. Once you return to normal eating and bowel movements, your weight will likely rebound quickly.

How to Lose Weight Long-Term

While you shouldn’t rely on pooping as a primary weight loss strategy, there are healthy and sustainable ways to lose weight long-term. Here are some effective strategies:

Cut Calories

To lose weight, you need to create a calorie deficit by eating fewer calories than you burn. Aim to cut out about 500 calories per day from your diet to lose about 1 pound per week.

Increase Physical Activity

Boost your physical activity through exercise, sports, or lifestyle changes like walking more. This increases the calories your body uses each day, making it easier to create a calorie deficit.

Eat More Protein and Fiber

Eating foods higher in protein and fiber can help fill you up on fewer calories, controlling hunger and decreasing calorie intake.

Change Unhealthy Habits

Cut down on saturated fats, processed foods, sugar-sweetened beverages, and other unhealthy items associated with weight gain.

With consistency and commitment to lifestyle changes, you can achieve gradual, steady, and lasting weight loss over time.


In summary, the reason you don’t usually lose weight right after pooping is that:

  • Poop doesn’t account for a large percentage of your overall weight.
  • Your body weight is constantly fluctuating up and down.
  • Scales can’t detect tiny changes in body weight from pooping.

Occasionally, such as after severe constipation, you may notice some weight loss from a bowel movement. But for day-to-day poops, it won’t make the scale budge.

Remember, while poop has mass, it only makes up about a pound of your total body weight. Normal fluctuations in hydration, stomach contents, and other factors tend to obscure any minimal weight loss from pooping. So next time you’re disappointed that the scale stays put after using the bathroom, remember it’s just science!

Poop Frequency Typical Daily Poop Weight
3 times per week 1/3 pound
Once per day 1 pound
3 times per day 1 pound

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