Constipation and weight gain: Is there a link?

Struggling to pass a stool and wondering if it’s making you put on a few pounds? There could very well be a connection.

Let’s unpack the potential link between the two, as well as what causes constipation and how to prevent it in the first place.

What is constipation?

In a nutshell, constipation is when you’re experiencing infrequent bowel movements. ‘Infrequent’ can mean different things to different people, because there’s a wide spectrum of what’s considered ‘normal’ when it comes to your toilet habits.

For some people, doing a number two a couple of times a day is standard, while for others, they may only go a couple of times a week. 

So while constipation technically involves having fewer than 3 bowel movements per week, your experience of the condition may vary depending on your own patterns [1].

As well as irregular bowel movements, you might also experience [2]:

• Hard, dry or lumpy stools
• Pain or strain when making a bowel movement
• Spending a long time on the toilet
• Feeling as if you haven’t completely passed stool
• Abdominal discomfort
• Bloating

What causes constipation?

There are lots of reasons why constipation can crop up, and they can be broadly defined as either medical or lifestyle-related causes and risk factors. Some of the most common include [2][3][4]:

Lifestyle causes

• Poor diet, particularly a lack of fibre
• Lack of exercise
• Inadequate hydration
• Stress
• Travel
• Ignoring the need to go to the toilet (the longer you refrain, the harder it is to pass a stool)

Medical causes

• Irritable bowel syndrome
• Coeliac disease
• Anal fissure
• Diabetes
• Hypothyroidism (underactive thyroid)
• Pregnancy
• A side effect of some medications, including GLP-1 medications Ozempic and Wegovy

Does constipation cause weight gain?

Well, kind of — but only temporarily. If you’re constipated, you might notice a higher number on the scales. But it's not true weight gain; it's simply because your body’s holding on to the waste, which does contribute to your body weight.

You might find that your weight returns to its baseline once you’ve had a bowel motion. The link between constipation and actual weight gain is more around the causes of each one.

This is because the things that trigger constipation are also connected with putting on weight — like poor diet, lack of physical activity, and inadequate hydration.

Weight gain is pretty simple. It happens when someone consumes more energy than they burn over an extended period. This energy is then stored in the body as fat, potentially making them gain weight.

Poor diet — particularly eating foods that are high in calories, salt, sugar and saturated fat, and low in fibre — drives weight gain because it can cause you to intake too much energy that may not get burned off. 

Foods rich in salt, sugar and saturated fat tend to be higher in calories anyway, however, each one can lead to weight gain in its own way. Salty and sugary foods are easy to overeat, while sugar in particular encourages your body to store fat, especially around your midsection [5][6].

Research has also demonstrated a link between saturated fats and obesity [7].

A sedentary lifestyle means the calories you consume have nowhere to go. Exercise uses energy, plus it boosts your metabolism and builds muscle — both of which are important for burning fat.

Lastly, while not necessarily a direct cause of weight gain, poor hydration can lead to a slower metabolism [8].

On the flip side, research shows increased hydration could help with weight loss thanks to water’s ability to support metabolic function [9].

Stress may also play a part because it makes your body produce elevated cortisol levels. Research shows that, as a result, you tend to change your eating patterns (often for the worse) and your body shifts how it stores fat, possibly leading to weight gain [10].

Small intestine bacterial overgrowth (SIBO) is also worth mentioning here, as being constantly constipated may lead to this bowel disorder, which is typically linked with weight gain.

Can constipation cause water retention?

If you’re experiencing water retention, you’ll likely notice swollen ankles and feet, minor weight gain, and a bloated tummy. You might also wonder if constipation is the reason behind it.

Constipation isn’t a direct cause, but it can make you feel bloated — in much the same way that water retention does. 

However, similar to the link between weight gain and constipation, there’s also a correlation between constipation and water retention: many of the things that trigger constipation can lead to water retention, too.

Dehydration can cause water retention because it interrupts your body’s natural fluid balance. Not drinking enough makes it hard for your body to expel fluids, causing them to accumulate in your system.

Fluid retention can also be due to poor diet, especially eating foods that are high in salt. Your body typically maintains a nice balance of sodium and fluids, but when you eat too much salt, your body holds on to the sodium and retains extra water to compensate.

Other causes of both constipation and fluid retention include pregnancy, medical conditions (including hypothyroidism), and some medications.

How to prevent constipation

So, what can you do to prevent constipation or ease it and get things flowing again?

Usually, it’s a case of implementing a few lifestyle changes that encourage regular bowel motions.

Eat a nutritious, high-fibre diet

Fibre is crucial for overall digestive health for several reasons. It bulks up your stools, keeps your gut bacteria in balance, and helps the muscles in your digestive system work smoothly [11].

There are 2 types of fibre: soluble and insoluble. The former acts as a stool softener and is found in foods like oats and other whole grains, sweet potatoes, apples, berries, and bananas.

The latter adds bulk to your stools (which speeds up the food going through your digestive tract) and is found in legumes, vegetables, fruit skins, nuts, seeds, and whole grains.

Stay hydrated

Drinking water is a must. It supports fibre to soften your stools, which makes them much easier to expel. You could also go for other fluids like fruit or vegetable juice, but water is the best way to stay hydrated [12].

The right amount of water to drink each day varies from person to person, but generally, you want to aim for around 8 cups [13].

Exercise regularly

Exercise supports your colon and the other muscles involved in passing stools, and helps get things moving [14].

Aim for 30 minutes a day on most days, if you can manage it. The additional benefit of moving more is that it’ll keep your overall health in check and support weight management.

Don’t delay bathroom trips

Resisting the urge means your body extracts more water from your stools, making them harder to pass. If you consistently keep ignoring the need to go, it can work against your body’s natural signals. Over time, this may lead to decreased sensitivity and increased constipation. 

Instead, use the bathroom whenever you experience the urge.

Stress less

Stress releases hormones like cortisol and adrenaline, both of which slow down your digestive system. As a result, you may experience constipation.

Stress can also make you crave processed foods, which we know are low in fibre and contribute to constipation. It can also reduce your desire to exercise, another crucial factor in maintaining gut health and a well-functioning digestive system.

To reduce stress, try activities like meditation, deep breathing, exercising, spending time with family and friends, or working towards a better work-life balance.

When to seek medical help

If none of these work to relieve your constipation, you experience chronic constipation (where it goes on for several weeks) or if the constipation is so bad it’s causing extreme discomfort, make an appointment with your doctor.

You should also see your doctor if there are other symptoms alongside the constipation.

Some of the signs to look out for include weight loss, blood in your stools, abdominal pain, nausea, vomiting or sudden changes in your bowel habits. These may be an indication of a more serious issue [16][17].

Lose weight with Juniper

If you’re looking for a comprehensive and effective weight loss solution, Juniper can help.

With Juniper's Weight Loss Programme, we combine GLP-1 weight loss medications, like Wegovy or Mounjaro, with a nutrition and exercise plan, so you know exactly what to do for the best results.

We also have a library of protein-packed recipes to take the guesswork out of eating — especially when you don't feel like it.

Plus, we have a team of expert dietitians and health coaches you can consult with, to help you work through any challenges you're experiencing during your weight management journey. This holistic approach sets you up for sustained weight loss, rather than a quick-fix solution.

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