Tag Archive for: fiber

The Function of Fiber

By Noel Ugarte, MS, RD | Registered Dietitian

Let’s talk about fiber. I’m sure most of us have heard that fiber is good for us – but how? It turns out that fiber can help manage and prevent many diseases.

What is Fiber?

Fiber is plant material that our bodies cannot fully digest. This means that the only food sources of fiber are plants. Vegetables, fruits, whole grains, and beans are all excellent sources of fiber. Fiber is a functional food. This means that as fiber travels through our bodies, it does different helpful jobs. But how does undigested plant material traveling through our body help improve our health?

Type 2 Diabetes

Fiber is technically a type of carbohydrate. The great news is, as stated above, we do not have the digestive tools to break it down into sugar. Instead, our stomachs break down fiber into smaller pieces. This takes a long time for our stomachs to do. Slower digestion time means that blood sugar levels will rise at a slower rate. This is great news for people who are trying to keep blood sugar levels steady. The American Diabetes Association recommends diabetics consume adequate fiber in their diets each day to help manage diabetes.

Whole grain bread, brown rice, beans, whole wheat pasta, oatmeal, popcorn, and potatoes with skins are all examples of high fiber carbohydrates.

Broccoli, carrots, onions, cauliflower, asparagus, green beans, eggplant, cucumbers, and celery are all examples of non-starchy vegetables. These vegetables do not raise blood sugar levels like potatoes and corn do. They are also packed with fiber!

High Cholesterol

Fiber may also help to lower LDL cholesterol (bad cholesterol) levels. Specifically, soluble fiber has been shown to help with this. Soluble fiber is a type of fiber that softens and grows when it comes into contact with liquid. Imagine what happens when you cook rice, oats, or dried beans – they soften and grow in size! As this thick fiber travels through your gut, it grabs some cholesterol that you ate in your meal and stops it from getting absorbed into your blood.

You can get soluble fiber into your diet by eating more lentils, beans, oats, chia seeds, fruits such as apples, oranges, and bananas, and vegetables such as brussels sprouts, carrots, and potatoes.

General Gut Health

Fiber is the main food source for the bacteria in our gut. It may not sound good to have bacteria in your gut, but in fact, these intestinal friends are necessary and help us to stay healthy. As they eat (or, rather, ferment) the fiber, they produce gas. This is why fibrous foods can sometimes cause bloating and gas! It’s important we feed them well in order to keep our gut bacteria diverse and flourishing.

According the the American Cancer Society, fiber has been linked to lowering colorectal cancer risk. It can also help to prevent polyps and diverticulitis flares. This is because the undigested plant material acts as a brush, brushing clean the lining of our intestines as it makes its way through us.

Fiber can also help regulate bowel movements. The different types of fiber – soluble and insoluble – work to change the shape and texture of our stools.  Soluble fiber absorbs water and becomes thick, insoluble fiber travels unchanged throughout the body making stools more bulky in size. These two functions – viscosity and bulking – help our stools to be more regular in schedule and texture.

The great news is that most fibrous foods have a mix of both types of fiber.

Weight Loss

Higher fiber diets have been linked to weight loss. Foods that are naturally high in fiber tend to be higher in vitamins and minerals and lower in calories. Think about the difference between cheese puffs and carrots. You can eat a lot more carrots for 100 calories than cheese puffs for 100 calories. Thus, when meals are higher in fiber, you are more likely to feel fuller for longer while taking in less overall calories.

How Much Fiber Do I Need?

Adult females should get about 25g fiber per day, and males should get about 38g fiber per day (or about 14g fiber per 1,000 calories per day).

If you are looking to increase your fiber intake, consider increasing your fiber intake slowly. Going from a low fiber diet to a normal fiber diet too quickly can cause abdominal pain and bloating. Try increasing intake by 5-10 grams every few days as tolerated and remember to drink plenty of water.

Take a look at some of these higher fiber foods. Which foods can you add into your diet today?

High Fiber Foods (4 grams or more)

FoodServing sizeGrams of fiber
Artichoke1 medium10.3
Beans, baked, plain1/2 cup5.2
Beans, black1/2 cup7.5
Beans, kidney, canned1/2 cup6.9
Beans, lima1/2 cup6.6
Beans, navy1/2 cup9.5
Beans, pinto1/2 cup7.7
Beans, white, canned1/2 cup6.3
Blackberries1/2 cup3.8
Bulgur1/2 cup4.1
Cereal, high fiber, bran1/2 cup4-9
Chickpeas, canned1/2 cup5.3
Lentils1/2 cup7.8
Mixed vegetables, frozen1/2 cup4
Pear1 medium5.1
Peas, green, frozen1/2 cup4.4
Peas, split1/2 cup8.2
Potato, baked with skin1 medium4.4
Potato, sweet, baked with skin1 medium4.8
Quinoa1/2 cup5
Raspberries1/2 cup4
Soybeans1/2 cup5.1
Academy of Nutrition and Dietetics (sources: US Department of Agriculture, Agricultural Resource Service. 2008. USDA National Nutrient Database for Standard Reference, Release 20. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl; accessed November 5, 2008. Nutrition Data.com: Nutrition Facts and Information, www.nutritiondata.com; accessed April 28, 2008. American Dietetic Association, Nutrition Care Manual: Constipation Nutrition Therapy, http://cms.eatright.org; accessed June 25, 2008.)

Moderate Fiber Foods (1-3 grams)

foodserving sizegrams of fiber
Banana1 medium3.1
Barley1/2 cup3
Beans, green or yellow1/2 cup2
Beets, canned1/2 cup1.5
Blueberries1/2 cup1.8
Bread, whole or cracked wheat, pumpernickel, rye1 slice2
Broccoli1/2 cup2.5
Brussels Sprouts1/2 cup2
Cabbage1/2 cup1.4
Carrots, frozen1/2 cup2.4
Carrots, raw1/2 cup1.6
Cauliflower1/2 cup2.5
Cereal, bran w/ raisins1/2 cup3.4
Cereal, wheat or oat1/2 cup2 – 4
Cherries, canned or fresh10 cherries1.4
Coconut, shredded1 oz.2.5
Corn, canned or frozen1/2 cup2.1
Cornbread2″x2″ piece1.4
Crackers, whole wheat4 crackers1.7
Cranberries1/2 cup2.6
Dates, dried5 dates3.3
Eggplant1/2 cup1.3
English muffin1 english muffin2
Figs, medium1 fig1.9
Fruit cocktail, canned1/2 cup1.2
Grapefruit1/2 cup1.4
Greens, such as turnips, beets, collards1/2 cup1.6-3.2
Kale, cooked1/2 cup1.3
Kiwi1 medium2.3
Melon1 cup1.4
Muffin, oat bran2 oz.2.7
Nuts, almonds1 oz.3.5
Nuts, pistachios, pecans, walnuts1 oz.2-3
Oat bran1/2 cup2.3
Oatmeal1/2 cup2
Okra1/2 cup2
Orange, 2 1/2″1 orange3.1
Papaya1/2 papaya2.8
Peaches, fresh or canned1 fresh or 1/2 cup canned1.5
Peanuts1 oz.1 oz.
Pears, canned1/2 cup1/2 cup
Peas, green, canned1/2 cup1/2 cup
Pineapple, fresh1/2 cup1.1
Plum, 2″1 plum1
Popcorn, air-popped1 cup1.2
Prune juice1/2 cup1.3
Prunes5 prunes3.5
Pumpkin, canned1/2 cup3.6
Raisins, seedless1/4 cup1.4
Rice, brown or wild1/2 cup1.8
Sauerkraut, canned1/2 cup3.4
Seeds, sunflower or pumpkin kernels1/4 cup1.1
Spaghetti, whole wheat1/2 cup3.2
Spinach, canned1/2 cup2.6
Spinach, frozen1/2 cup3.5
Squash, all varieties1/2 cup2.9
Strawberries1/2 cup1.7
Tangerine1 tangerine1.5
Tomato sauce, spaghetti or marinara1/2 cup3..3
Tomatoes, raw1 medium1.5
Tortilla, corn, 6″1 tortilla1.6
Veggie or soy patty1 patty3.4
Wheat germ2 tbsp.1.7
Academy of Nutrition and Dietetics (sources: US Department of Agriculture, Agricultural Resource Service. 2008. USDA National Nutrient Database for Standard Reference, Release 20. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl; accessed November 5, 2008. Nutrition Data.com: Nutrition Facts and Information, www.nutritiondata.com; accessed April 28, 2008. American Dietetic Association, Nutrition Care Manual: Constipation Nutrition Therapy, http://cms.eatright.org; accessed June 25, 2008.)

We’re Here to Help

Learning the ins and outs of a healthy diet can be tricky. Whether you’re just getting started or need a refresher, NOAH nutrition educators are here to guide and support you in living your healthiest life. For more information on nutrition services at NOAH, visit our website, or call 480-882-4545.


Academy of Nutrition and Dietetics

American Cancer Society Guideline for Diet and Physical Activity

Mechanisms of Dietary Fiber – Fiber Facts

Types of Carbohydrates | ADA (diabetes.org)

Whole Grains, Refined Grains, and Dietary Fiber | American Heart Association

Fiber and Your Colorectal Health

By Stephanie Olzinski, MS, RDN |Nutrition Supervisor

Fiber is an important nutrient. But why is it important and what can we eat for more fiber are common questions.

Simply put, fiber helps keep us ‘regular’ going to the bathroom more frequently. That is a good thing! When we are regular, stool spends less time in the large intestine. That means less chance of harmful bacteria or carcinogens (substance capable of causing cancer) building up. In a study, The American Medical Association found that when 1,500 patients with early-stage colorectal cancer began eating more fiber-rich foods, it reduced their risk of dying from colorectal cancer by 20%!

Good Sources of Fiber

  • Beans
  • Lentils
  • Oats or oatmeal
  • Nuts
  • Seeds
  • Fruits and vegetables
  • Whole grains or whole wheat products like wheat bread and wheat pasta

A good tip for determining what foods are a good source of fiber is to read the nutrition facts label on products. Grab a package of bread at your house or the next time you’re in the grocery store – if the line for fiber says one serving contains at least three grams of fiber per serving, then it’s a good source of fiber. You can also look for 100% whole wheat as the first ingredient. 

Daily Fiber Intake

Fiber recommendations are different for everyone depending on age and any other medical conditions. In general, achieving an intake of over 20 grams of fiber per day is recommended. Start by trying to add just one extra fiber source daily, like switching to oatmeal for breakfast or adding a larger serving of vegetables at dinner. Not only does a gradual approach make it easier to adapt to new eating habits over time, introducing fiber into your diet slowly prevents bloating and cramping sometimes associated with increased fiber intake.

Kickstart your new eating habits with these tasty, fiber-rich, recipes:

Pozole Verde with Chicken

Pozole Verde with Chicken - A Good Source of Fiber

Hominy is a product of corn and is considered a grain. Low in fat and high in fiber, it has a similar taste to corn though the texture is much different. A main staple in Mexican cuisine, hominy is highlighted in this flavorful soup. We’ve taken it to another level by using chicken instead of the traditional pork shoulder. Also, add in those veggies for an added nutrition benefit and this hearty soup will be a crowd pleaser on any table.

Summer Black Bean and Rice Salad

Summer Black Bean and Rice Salad - Good Source of Fiber

This cold salad is perfect for a warm spring day! It’s packed with protein, high in fiber and delicious flavors that will rock your taste buds. Make this dish ahead of time and keep refrigerated until it’s time to serve! Make this recipe even more fiber-rich by choosing brown rice over white.

Avo-Mango Smoothie

Avo Mango Smoothie - Good Source of Fiber

The bright flavors of the mango and the creaminess of the avocado and banana is a perfect match. Plus you get some amazing health benefits from this smoothie that make it a yummy treat for anyone!

Drink Plenty of Water

Speaking of helping things move through your digestive tract, it is extremely important to drink more water once you start increasing your fiber intake. Constipation can be an unwelcome side-effect of consuming fiber without being sufficiently hydrated. Most people require a minimum of 64 ounces of water per day. You can use the same gradual method here and start by drinking one extra glass or bottle of water each day. It can also be fun to get a special water bottle for yourself, or set a reminder on your phone to remember to take a few extra sips of water throughout the day.

While making just a couple adjustments to your diet can impact your colorectal (and overall) health; there are many other factors like age, family history… that contribute to your risk of colorectal cancer. The next step after prevention is detection. If you are age 50 or older and at average risk for colorectal cancer, NOAH providers recommend you begin your regular screenings now.  It just might save your butt.