everything you need to know about fiber

Why fiber matters: health benefits and best sources

Fiber, much like fat, has often been overlooked or misunderstood. It’s an essential nutrient that plays a critical role in maintaining a healthy digestive system, promoting satiety, and supporting healthy blood sugar levels. Due to its many benefits, it’s an important part of any diet. Unfortunately, many of us do not meet the daily recommendations for fiber. The Academy of Nutrition and Dietetics suggests that women should aim for about 25 grams of fiber per day, while men should target close to 38 grams per day (1). Most people consume only about half of these amounts, missing out on the substantial health benefits that a fiber-rich diet can offer.

Understanding the importance of fiber and how to incorporate it into your daily routine can have a positive impact on your everyday living. This post will explore what fiber is, the numerous health benefits it offers, and the best whole food sources to include fiber in your diet. By the end, you'll have all the tools you need to start boosting your fiber intake, thus reaping the rewards of this often underappreciated nutrient.

What is fiber?

Fiber, unlike other essential nutrients we consume, is a carbohydrate that our bodies are NOT able to digest or break down. Because fiber moves throughout the body undigested, it helps regulate the body's use of sugars, regulating hunger and keeping blood sugar in check (2). There are two different types of fiber:

1. Soluble fiber: Soluble fiber dissolves in water to form a gel-like substance that increases satiety and supports regular bowel movements. It can help lower blood cholesterol and glucose levels. Common sources include oats, peas, beans, apples, citrus fruits, carrots, and barley (3).

2. Insoluble fiber: Helps food pass through your digestive system more quickly, by increasing stool bulk. It’s beneficial for those who struggle with constipation or irregular bowel movements. Common sources include whole-wheat flour, wheat bran, nuts, beans, and vegetables like cauliflower, green beans, and potatoes (3).

Health benefits of fiber:

1. Promotes healthy digestion (including gut health)  

   Fiber plays a crucial role in maintaining a healthy digestive system. By adding bulk to the stool, fiber facilitates its passage through the intestines, promoting regular bowel movements. This action helps prevent constipation and ensures that waste moves efficiently through the digestive tract (4). Additionally, a diet rich in fiber supports the health of the gut microbiome by providing nourishment for beneficial bacteria. These bacteria aid in digestion and contribute to overall gut health, enhancing nutrient absorption and supporting immune function (5).

2. Blood sugar regulation

   By slowing the absorption of sugar into the bloodstream, soluble fiber helps to stabilize blood glucose levels (6). This regulation is particularly beneficial for individuals with diabetes, as it aids in preventing sharp spikes in blood sugar (7). Consuming foods high in soluble fiber can contribute to more stable blood sugar levels throughout the day, enhancing overall glycemic control and reducing the risk of complications associated with diabetes (8).

3. Heart health

   A high-fiber diet can help reduce cholesterol levels, particularly LDL (low-density lipoprotein) cholesterol, often called "bad" cholesterol. Lowering cholesterol levels can reduce the risk of heart disease and improve overall cardiovascular health. Regular consumption of fiber-rich foods contributes to maintaining a healthy lipid profile, promoting heart health, and reducing the likelihood of cardiovascular issues (9).

4. Weight management

   High-fiber foods offer a natural solution for those seeking to manage their weight. By slowing down digestion and promoting a sense of fullness, high-fiber foods can help reduce calorie intake and support sustainable weight loss. Additionally, the satiety boost provided by high-fiber foods can help minimize mindless snacking and overeating, leading to a healthier and more balanced eating routine and relationship with food (10).

Best whole food sources of fiber

Whole grains

• Brown rice

• Oats

• Quinoa

• Barley

• Farro

• Whole wheat products like bread, crackers, and tortillas

Seeds

• Chia seeds

• Hemp seeds

• Flax seeds

• Pumpkin seeds

• Sunflower seeds

Beans and legumes

• Lentils

• Black beans

• Garbanzo beans

• Kidney beans

• Navy beans

• Split peas

• Edamame

• Lima beans

• Pinto beans

Fruit

• Apples (with skin) 

• Avocado

• Strawberries

• Pears

• Oranges

• Cherries

• Raspberries

• Bananas

• Figs

Vegetables

• Brussels sprouts

• Kale

• Broccoli

• Carrots

• Peas

• Cauliflower

• Collard greens

• Potatoes

Practical tips to increase your fiber intake

Begin your day with fiber: Opt for a whole-grain piece of toast and add some avocado or enhance your morning smoothie by adding high-fiber fruit, chia seeds, or flaxseeds.

Snack on fruits and vegetables: Keep fresh fruits and vegetables readily available for quick and healthy snacks. I personally keep an applesauce pouch with me whenever I pack snacks on the go! 

Incorporate beans and legumes: Add beans or lentils to your soups, salads, and grain bowls for an easy fiber boost.

Choose whole grains: Select whole-grain bread, pasta, and rice instead of refined grains to increase your fiber intake.

Stay hydrated: Drinking plenty of water helps fiber work effectively in your digestive system.

The bottom line

Incorporating more fiber into your diet is one of the simplest yet most effective ways to improve your overall health. From regulating blood sugar levels to aiding in weight management and promoting digestive health, fiber plays a crucial role in maintaining a balanced and healthy lifestyle. By choosing whole-food fiber sources, you can ensure you get a rich supply of this essential nutrient. Small changes can lead to significant health benefits! Start adding more fiber to your meals today and enjoy the long-term rewards of a fiber-rich diet.

 Ready to increase your fiber intake? Give one of these recipes a try!

• Mediterranean power bowl

• Fall harvest kale salad

• The smoothie I'll be drinking until winter hits

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Written by Kelanie Garcia

Kelanie is a full-time student at California Polytechnic University, San Luis Obispo. She’s a nutrition major with an entrepreneurship minor, aspiring to become a Registered Dietitian. Kelanie is passionate about sharing the impacts of the Mediterranean diet, as it has transformed her relationship with food and wellness while being a college student. In her free time, she loves to test recipes, run outdoors, and improve her photography skills.

This post was reviewed by Kelly Powers, MA, RDN. Kelly is a Registered Dietitian and Culinary Nutritionist who takes a holistic approach to nutrition and health. She’s a recipe developer with a food blog highlighting whole foods, simple recipes, and her life in San Francisco. Kelly is the creator of Weeknight Dinners, a weekly meal plan program that helps people get back in the kitchen and feed themselves well. Kelly specializes in meal planning, the Mediterranean diet, and sustainable behavior change, helping her clients reach their health goals while improving their relationship with food. She’s also a nutrition consultant for health and tech startups, food companies, and brands she believes in.