A diet low in fiber can sneak up on you with some less-than-pleasant symptoms — and it's essential to recognize them before they impact your well-being. As a Registered Dietitian, I've seen first-hand how fiber, or the lack thereof, can play a crucial role in your health. 

Fiber, a type of carbohydrate that the body can't digest, is vital for keeping your digestive system running smoothly. Fiber also aids in weight management, supports a healthy gut microbiota, and helps prevent diseases such as diabetes and heart disease .¹ In this blog, you'll find an expert-guided tour through the signs that may indicate your diet is low in fiber and why bumping up your fiber intake could be a game-changer for your health.

1. You’re Feeling Constipated or Bloated

Difficulties with bowel movements, commonly expressed as constipation, can often be directly linked to fiber intake. Fiber, found abundantly in fruits, vegetables, whole grains, legumes, and OLIPOP sodas, acts as the body's natural way of keeping the digestive system running smoothly. It absorbs water, which helps to soften the stool and increase its bulk, making it easier to pass through the intestines. A diet lacking adequate fiber can lead to harder stools that are difficult to pass, resulting in constipation.² Incorporating a healthy amount of dietary fiber can thus play a crucial role in making bowel movements more consistent and effortless.

2. You’re Still Feeling Hungry After Eating

Fiber plays a remarkable role in keeping you feeling full and satisfied, acting as the secret ingredient to a successful diet. But how does it work? Fiber takes its time meandering through your digestive system, slowing down the emptying process of your stomach. This slow motion means you feel full for longer, reducing the temptation to snack between meals. A diet low in fiber, in contrast, can lead to quicker digestion and more frequent hunger pangs, nudging you toward extra snacking.³ This is why incorporating a good amount of fiber into meals can be a game-changer for managing your hunger and sustaining energy throughout the day.

3. You Have High Cholesterol

Fiber, particularly soluble fiber, plays a pivotal role in heart health by helping to lower cholesterol levels. It works by binding with cholesterol particles in the digestive system and moving them out of the body before they're absorbed.⁴ This process not only helps reduce the overall cholesterol levels but also aids in preventing the buildup of cholesterol in the arteries, which can lead to heart disease and stroke. Incorporating high-fiber foods into your diet, such as oats, beans, lentils, fruits, and vegetables, can thus be a strategic move towards maintaining a healthy cardiovascular system.

4. You’re Always Tired

Fiber plays a crucial role in managing and balancing blood sugar levels, thereby preventing the rapid spikes and drops that can lead to energy dips and feelings of exhaustion. Soluble fiber, in particular, slows the absorption of sugar in the bloodstream, contributing to more stable blood sugar levels over time. On the flip side, diets low in fiber lack this positive effect on blood sugars, making individuals more susceptible to the intense fluctuations often linked to fatigue. 

5. You’re Experiencing Hemorrhoids

A diet lacking in fiber is a key contributor to constipation, as fiber helps to bulk up stools and promote regular bowel movements. When the body struggles to eliminate waste due to insufficient fiber intake, it can lead to increased strain during bowel movements. This strain not only exacerbates constipation but can also lead to the development of hemorrhoids, and painful swollen veins in the rectal area.⁵ No fun!

6. You’re Urinating Frequently and Always Thirsty 

A diet low in fiber can lead to several physiological disturbances, including an imbalance of electrolytes and dehydration, which may increase urination frequency. Fiber plays a crucial role in maintaining fluid balance within the body, as it helps to absorb and retain water in the digestive system.⁶ Without adequate fiber, water is not absorbed as efficiently, often causing it to pass through the body more quickly. This rapid transit can pull electrolytes, such as sodium and potassium, along with it, causing an electrolyte imbalance. Electrolytes are vital for regulating hydration levels, muscle contractions, and nerve function. When the body attempts to rectify this imbalance by drawing water from cells to replace lost fluids, it can lead to dehydration, ultimately resulting in increased urination as the body tries to excrete excess water and rebalance electrolyte levels.

7. You’re More Likely to Experience IBS & Other Health Conditions

A diet low in fiber is a risk factor for several conditions, including irritable bowel syndrome (IBS), diabetes, and bowel cancer.⁷ Fiber plays a crucial role in maintaining digestive health by normalizing bowel movements and helping to prevent constipation. It also aids in controlling blood sugar levels, which can reduce the risk of developing diabetes. Furthermore, a high-fiber diet may lower the risk of colorectal cancer by helping to keep the digestive tract clean and healthy. 

8. Your Skin Health May Suffer

Lastly, a low-fiber diet can negatively impact your skin health due to its effects on the body's digestive and detoxification systems. Fiber plays a crucial role in promoting a healthy gut microbiome, which is essential for effective digestion and absorption of nutrients vital for skin health. Without sufficient fiber, the body may struggle to eliminate toxins through the digestive tract, potentially leading to unhealthy-looking skin. 

Tips to Add More Fiber to Your Diet

So, fiber is pretty important for managing many areas of your health! Here are a few of my top tips for adding more health-boosting fiber to your diet: 

• Incorporate a variety of fruits and vegetables into every meal, focusing on leafy greens, berries, and root vegetables.
• Choose whole grains over refined ones; opt for whole wheat bread, brown rice, and whole grain pasta.
• Add legumes such as beans, lentils, and chickpeas to soups, salads, and main dishes for an extra fiber boost.
• Snack on nuts, seeds, and fresh fruit rather than processed snacks.
• Begin the day with a high-fiber breakfast cereal, or oatmeal topped with fruits and nuts.
• Sip on OLIPOP instead of other sodas or sparkling beverages to provide your body with 9 grams of prebiotic fiber per can. 

Symptoms of Low Fiber Diet: The Takeaway

Most people don’t consume enough fiber. This is primarily due to diets heavy in processed and refined foods that lack the natural fiber found in fruits, vegetables, whole grains, and legumes. Additionally, the convenience and palatability of fast food and snacks, which are typically low in fiber, contribute to inadequate fiber intake. Busy lifestyles also play a role, as it’s easy to opt for quick, less nutritious meal options over fiber-rich alternatives that often require more time for preparation and cooking.

However, eating a low-fiber diet can have detrimental effects on your health. Include around 25 grams of fiber per day if you are a woman and about 38 grams if you are a man for optimal health.⁸ Eating more beans, drinking OLIPOP, and making a point to eat your fruits and veggies can have a profound effect on your health, all thanks to the fiber these foods provide. 

Sources

1. Anderson, J. W., Baird, P., Davis, R. H., Ferreri, S. P., Knudtson, M., Koraym, A., Waters, V., & Williams, C. L. (2009). Health benefits of dietary fiber. Nutrition Reviews, 67(4), 188–205. https://doi.org/10.1111/j.1753-4887.2009.00189.x
2. Constipation. (2024, January 1). PubMed. https://pubmed.ncbi.nlm.nih.gov/30020663/
3. Akhlaghi, M. (2022). The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences. Critical Reviews in Food Science and Nutrition, 1–12. https://doi.org/10.1080/10408398.2022.2130160
4. Surampudi, P., Enkhmaa, B., Anuurad, E., & Berglund, L. (2016). Lipid Lowering with Soluble Dietary Fiber. Current Atherosclerosis Reports, 18(12). https://doi.org/10.1007/s11883-016-0624-z
5. Johanson, J. F., & Sonnenberg, A. (1990). The prevalence of hemorrhoids and chronic constipation. Gastroenterology, 98(2), 380–386. https://doi.org/10.1016/0016-5085(90)90828-o
6. Qian, Q. (2018). Dietary influence on body fluid Acid-Base and volume balance: The deleterious “Norm” furthers and cloaks subclinical pathophysiology. Nutrients, 10(6), 778. https://doi.org/10.3390/nu10060778
7. Dietary fiber and risk of irritable bowel syndrome: a case-control study. (n.d.). PubMed. https://pubmed.ncbi.nlm.nih.gov/30774803/
8. Rough up your diet. (2019, July 24). NIH News in Health. https://newsinhealth.nih.gov/2010/08/rough-up-your-diet

Meet our Expert This article is written by Lauren Manaker MS, RDN, LD. Lauren Manaker is an award-winning registered dietitian, book author, and freelance writer. Her work can be found in many major media outlets and on her women’s health nutrition-focused Instagram account @LaurenLovesNutrition. Raised in sunny South Florida and now living in Charleston, South Carolina, she has a love for the ocean and would be living on a houseboat if she had her way. She currently lives with her husband, young daughter, and 70-pound rescue pup.