Are you getting enough fiber or is your digestive system trying to tell you otherwise? Discover the common signs of a low-fiber diet, the potential long-term health risks and simple ways to give your gut the daily support it needs.
Content outline
Fiber is mostly known for keeping you regular in the toileting department. However, its benefits reach much deeper, in fact deep enough to say life sustaining. Consuming enough fiber supports your gut bacteria, enabling them to produce important compounds such as short chain fatty acids (SCFAs). SCFAs are a major component in keeping your immune system in a regulated state and have many other health benefits.
Eating enough fiber is also important for heart health, blood sugar control, and helping maintain your appetite. Not consuming enough fiber in the diet can lead to digestive problems and even long term health problems.
Here, we explore the symptoms of not getting enough fiber in your diet, both in the short and long-term, and what you can do about it.
What is fiber, and why do you need it?
Dietary fiber is a type of diet that mainly comes from plant foods [1]. There are two types of fiber, both of which are extremely important to processes that contribute to good health. These two types of fiber are:
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Soluble Fiber dissolves in water to form a gel [2]. In this state, it is fermented by your gut bacteria, a process that leads to SCFA and vitamin production. The gel-like substance can also slow digestion and help sugar enter the blood stream slowly rather than causing a sharp spike after a meal. Soluble fiber also binds to cholesterol to help remove the bad types from our blood.
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Insoluble fiber travels to your colon where it adds essential bulk to stools, enabling an easier, more comfortable exit [3]. This helps to prevent constipation and the build up of dangerous toxins.
How much fiber do you need?
How much fiber you need depends on where you live in the world, as different health authorities and governing bodies suggest different amounts.
The USDA recommends that men consume 38g and women consume 25g of fiber per day [4].
Not in the US? Find out how much you need in our guide: Why You Need 36% of Your Daily Fiber: A Deep Dive into Modern Dietary Gaps.
What are the symptoms of not getting enough fiber?
Although it may not always be clear, there are a number of early noticeable symptoms that can highlight you are not getting enough fiber. These early signs often affect the digestive system, most commonly the frequency and consistency of your bowel movements. Here are some of the common signs that your body may be low on fiber:
Constipation or hard stools
Being constipated is one of the first red flags that you might be lacking fiber in the diet. Fiber plays an important role in bulking up your stools, making them easier to pass. It adds to the size, shape, and consistency of the stool [5].
Constipation symptoms include:
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A reduction in the number of times you pass a stool in a week
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Straining to pass a stool
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Passing dry, hard, or lumpy odd shaped stool
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A feeling of still being full even after you have passed a stool [6]
A low fiber intake is not the only cause of constipation, there may be other reasons like underlying health conditions, taking medication, your lifestyle, and even low physical activity can play a part.
Top tip: Drink plenty of water every day, aim for at least 2L, this will help keep you hydrated as well as help the fiber work properly to soften your stools [7].
Feeling hungry soon after eating
Feeling hungry soon after you have eaten could be a sign that your meal does not contain enough fiber. Meals that are high in fiber will take longer to chew and digest, so you feel fuller for longer after a meal [8]. Meaning you’ll be less likely to snack in between meals.
Meals containing mainly processed foods can make you feel hungry soon after you last ate. Adding fiber such as beans, whole grains, or vegetables to your meal will help you stay fuller for longer.
Irregular bowel habits
A low fiber diet can play havoc with your digestive system, causing variations to the frequency and consistency to your stool, ranging from loose to hard. By adding fiber you will help to maintain a consistent bowel action and help you feel more satisfied.
Sudden changes to bowel action or sudden diarrhoea could have other causes rather than a lack of fiber. If you are concerned or you have persistent or severe painful diarrhoea, or diarrhoea accompanied with blood, fever, or sudden weight loss, contact your physician.
Feeling bloated when you eat fiber
Bloating or feeling gassy after eating fiber does not mean fiber is bad for you. If you suddenly eat higher amounts of fiber than you usually do it can cause bloating [9]. Sometimes this can become painful, but it usually does not last long.
It’s caused by your gut bacteria who are busy fermenting soluble fiber. When they break down fiber into beneficial metabolites, it creates gases which can lead to bloating. Over time, your gut will adjust and get used to your increased fiber intake, making it a more comfortable and satisfying process.
What are the long-term risks of a low-fiber diet?
Having an occasional treat day or a reduced fiber intake is unlikely to have too much of a long-term impact, but continuously avoiding fiber increases the risk of some chronic health conditions. Most of these begin with a less abundant and diverse gut microbiota.
A less well-supported gut microbiome
Your gut microbiome is the collection of microorganisms, including bacteria, viruses, fungi, and archaea that live in your digestive tract. Some of these organisms have the job of fermenting fiber and producing short-chain fatty acids, which are vital processes for a healthy gut.
These compounds also provide the cells that line the colon with enough energy to carry out their important jobs, as well as helping to support the overall gut environment. If you consume very little fermentable fiber too often, you may be underfueling these beneficial bacteria and lead to dysbiosis or an imbalance microbiome. Over time, dysbiosis can contribute to a several digestive symptoms and chronic diseases, including:
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Inflammatory bowel disease (IBD)
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Obesity
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Type 2 diabetes
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Liver disease
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Heart disease
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Colorectal cancer [10]
Higher cholesterol and poorer heart health
Certain soluble fibers reduce cholesterol absorption in the digestive tract, a powerful factor in reducing the risk of heart attacks, strokes, and peripheral artery disease. Better cardiovascular health is also more common in people that eat a high-fiber diet.
A major systematic review and meta-analysis published in The Lancet found that people with higher fiber intakes had lower rates of coronary heart disease, strokes, and several other chronic health outcomes than those with the lowest fiber intakes [11].
Less stable blood sugar levels
Research shows that consuming soluble fiber can help reduce the sharp rises in blood sugar after eating that is synonymous with eating high carbohydrate foods[12].
Foods high in fiber, like beans, whole grains, vegetables, and some fruits, are also gentler on blood sugar than most refined carbohydrates. If these foods are regularly replaced with low-fiber alternatives, healthy glucose levels may be more difficult to control.
In the long term, those with diets that are higher in fiber are associated with a lower risk of developing type 2 diabetes [13].
Increased risk of colorectal cancer
Dietary fiber helps move waste through the bowel and supports the microbial production of short-chain fatty acids. These are amongst the possible reasons why better colorectal health is associated with higher-fiber diets.
A systematic review and meta-analysis published in The BMJ found that an increased fiber intake is associated with a lower incidence of colorectal cancer [14]. This was particularly true in those with diets containing whole grains, rather than relying entirely on supplements.
Why are so many people falling short?
There are many reasons why people are falling short of their daily fiber requirements. Busy modern lifestyles rely heavily on ultra-processed or convenience foods that have their natural fiber stripped from them during the manufacturing process. Some of the common foods that can contribute a low fiber intake include:
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White bread, white rice or refined pasta
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Fast food and convenience meals
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Low-fiber snack foods
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Meat and dairy without enough plant foods alongside them
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Fruit juice instead of whole fruit
A good amount of fiber can also be removed by peeling fruits and vegetables. Reaching your fiber needs can be harder for those with restrictive diets and a limited range of foods.
Find out more about “Getting Your Fiber from Food vs. Supplements: A Realistic Guide for Busy People”.
How to increase your fiber intake
You do not need to transform your diet overnight. Small consistent changes can all add up. Whether you’re simply just busy, travelling, or not sure where to start when it comes to fiber, there are several things you can do to gradually increase your fiber intake, such as:
✅Replace refined breakfast cereal or toast with oatmeal or a whole-grain option, such as bran flakes, porridge, or wholemeal toast.
✅Add beans, chickpeas, or lentils to soups, salads and sauces.
✅Snack on fruit, vegetables, nuts, and seeds instead of cakes, pastries, and crisps.
✅Choose wholegrain bread, pasta, and brown rice more often.
✅Keep edible skins on fruits and vegetables after washing them to retain their fiber content.
✅Add berries, seeds, or chopped nuts to yogurt for a satisfying breakfast, snack, or desert.
✅Check nutrition labels and compare the fiber per serving.
✅Use a convenient soluble fiber product, such as The Clear Jar’s 2.5X Potent Fiber, to help close the gap when food alone falls short.
If your body is not used to fiber, increasing it gradually over several days or weeks can help build your tolerance and reduce the chance of uncomfortable digestive symptoms, like bloating and gas. It’s also important to remember to drink plenty of water, especially when increasing how much fiber you eat, to help it keep moving through your digestive tract.
Summary
A diet rich in a variety of fiber rich foods holds so many benefits. These benefits not only help make the whole digestive processes easier, but they have a major knock on effect that go a long way in preserving our long term good health giving us an easier journey as we move through life.
It is important to ensure our diet holds everything we need, but knowing there are additional supplements that can fill the gap when it comes to topping up the fiber in a particular meal can help us keep our very important diet right where we need it for our continued good health.
The Clear Jar’s 2.5X Potent Fiber provides 10 grams of tasteless soluble fiber per serving, which is around 36% of the FDA Daily Value. It dissolves into water, coffee, tea, or smoothies without changing their flavor, providing a convenient way to supplement a balanced diet. If you want to support fiber intake and hydration in one simple drink, Fiber-O-Lytes combines electrolytes with 6 grams of soluble fiber per serving. Sugar-free flavored and unflavored options make it easy to find one that fits your routine.
Written by: Leanne Edermaniger, M.Sc. Leanne is a professional science writer who specializes in writing about human health and wellbeing. Her work focuses on translating complex medical science into evidence-based, practical health guidance.
