A Dietitian’s Guide to Eating More Fiber

by Nate Widom

Fiber – it’s an essential carbohydrate for optimum health. It’s responsible for a plethora of positive benefits, and there’s a high likelihood that you don’t get enough, even if you eat a few fruits and veggies daily. In fact, only 1 in 20 Americans is reaching the recommended daily amount.¹ I sat down with Registered Dietitian Jeannie Versagli to uncover the reasons behind our fiber deficit and learn easy tips to incorporate more fiber into our diets.

Importance of Fiber

Fiber directly affects how you immediately feel. In the short term, it makes you feel fuller and relieves constipation. Long-term, it’s linked to reducing the risk of many chronic diseases. Eating the right amount will help improve your weight, digestion, cholesterol, immune system, brain function, and, especially, your gut health.²
How you feel after snacking also depends on fiber. You’ve probably experienced a blood sugar spike – the “crash” you feel after eating a cookie or other highly processed, sugary food. “Fiber minimizes the sugar spike that you would get from a carbohydrate,” Jeannie explains.
Here’s how it works: Fiber binds some of the glucose (sugar) in the digestive tract, which minimizes its absorption. This decreases the available amount of glucose absorbed by the body, lessening the potential for a blood sugar spike.
Besides a “crash,” blood sugar spikes may lead to short-term effects such as brain fog, increased thirst, and headaches. Chronically high blood sugar can cause more serious illnesses, like type 2 diabetes, over time. Fibrous foods slow down spikes, even if they naturally contain sugar, like fruit.
The same process transpires with LDL (bad) cholesterol. Like glucose, fiber also limits the absorption of LDL cholesterol in your digestive tract, too. This helps prevent plaque from building up in your arteries – too much can lead to heart attacks and strokes.^3,4
But getting enough fiber can be tricky. “Typically, you want to get in 25-35 grams of fiber [daily]. It can be a challenge,” Jeannie says.
You’ll find fiber in many fruits, whole grains, veggies, beans, seeds, and legumes. Still, even those who eat fibrous foods often struggle to meet the recommended intake. Jeannie explains this phenomenon and offers suggestions to increase your fiber intake easily.

Your gut is a microbiome filled with trillions of healthy bacteria. They influence your weight, mood, anxiety, immune system, sleep, and the development of diseases like irritable bowel syndrome (IBS), Crohn’s, leaky gut syndrome, and more. Fiber plays a key role in the health of these bacteria.

Essentially, fiber acts like a natural filter in your digestive system. It works away to sift out things you don’t want too much of, especially glucose and cholesterol.

Soluble vs Insoluble Fiber

There are two types of fiber: soluble and insoluble. Soluble fiber dissolves in liquid in your body, which then turns into a gel-like substance that slows down digestion. This also helps improve blood sugar and cholesterol levels. Meanwhile, insoluble fiber bulks up your stool.
You can find soluble fiber in whole grains, apples, bananas, veggies and oatmeal. Good sources of insoluble fiber include fruit and vegetable skin, popcorn, and leafy greens.⁵
“There are certain foods that have [relatively equal amounts of] soluble and insoluble,” Jeannie explains, but many high-fiber foods skew towards one or the other. Overall, getting a wide variety of fiber will satisfy!

Five Reasons Why People Don’t Get Enough Fiber

1.) Misconceptions About Carbs

Jeannie sees an ever-increasing trend of people viewing all carbs as bad. This is problematic because fiber is, in fact, a carb. Yes, some carbs are more nutritious than others. Simple carbs like bread, cakes, and sweets are often high in calories, fat, and/or sugar. Typically, they also lack fiber! Complex carbs like fruit, vegetables, and whole grains are nutrient-dense and full of fiber.
Jeannie does her best to reinforce the importance of carbs, especially complex carbs, with her clients. These carbs are our primary source of nutrients like magnesium and vitamins C and E, not to mention our primary source of energy! Put simply, don’t give all carbs a bad rap – just enjoy simple ones in moderation!

2.) Skipping Nutrition Labels

Jeannie regularly notices the public skipping nutrition labels on food packaging. The label is crucial because it’ll help you avoid the next couple of mistakes! It’ll immediately show a product’s fiber content along with any critical nutrients and ingredients.

3.) Popularity of Refined Food

Refined and ultra-processed foods are everywhere! But refining grains removes much of their natural fiber. Jeannie mentions that carbohydrate-based products with less than 3g of fiber per serving are considered low in fiber and are usually refined. This rule applies to all of the foods you’d expect – cookies, cakes, etc. – as well as many you may not think of – crackers, sauces, bread, and cereals!
To get a sense of how refined a food is, look at the fiber and ingredients on the nutrition label. As a rule of thumb, it’s best to see only a few ingredients, most of which are recognizable. If a product has low fiber and many ingredients you don’t recognize, it’s most likely highly refined.

4.) Shady Marketing Tactics

It’s no secret that companies add sneaky labels and buzzwords to their products to make them seem healthier than they are. And as a result, people get a false sense of a product’s fiber content. Jeannie frequently sees people fall victim.
“You can say whole grain in there, but it may not necessarily be high fiber,” Jeannie explains. In other words, don’t automatically assume that bread with healthy-sounding claims on the front contains much fiber. This is true even for multigrain, whole-wheat, and whole-grain varieties. They can be refined and lack fiber, too, so check nutrition labels to verify.

5.) Only Sticking to Fruits and Veggies

Jeannie sees many people eat a couple of servings of fruit and vegetables daily and assume they meet their fiber requirement. But usually, they didn’t.
It’s a harsh truth. Even though fruits and veggies are known for being fibrous, solely relying on them likely won’t get you to the daily recommendation of 25-35g. Other food groups, like whole grains, legumes, beans, nuts, and seeds should be considered too! To meet her goal, Jeannie will eat a variety of foods from all these food groups each day, not just fruits and vegetables.

Three Easy Tips to Increase Fiber

Reaching your fiber goal may seem daunting, even if you eat relatively well. Still, Jeannie stresses that doing so is much easier than you think! Aside from checking nutrition labels, she shares easy tips to help.

1.) Add Fibrous Sides and Snacks

Simply put, one of the easiest ways to increase your fiber is to add fibrous foods to your current diet. Most common fruits, veggies, nuts, and beans will have around 2.5-7g of fiber per serving. Below are some options perfect for a side or snack!⁶

Fruits
apple: 6g
3 medium figs: 5g
pear: 4g
orange: 3g

Veggies
1 cup of cooked kale: 7g
1 medium potato or sweet potato: 5g
½ cup of green peas: 4g
½ cup of asparagus or broccoli: 3g

Beans and Pulses
½ cup of black beans, pinto beans, or lentils: 7g
½ cup of kidney beans: 6g
½ cup of chickpeas: 4g

2.) Add and Blend Seeds

Jeannie is fond of topping meals you already eat with seeds since it’s a simple way to increase fiber and antioxidants. They can add a little extra crunch blend seamlessly into homemade smoothies.

2 tbsp of
Flaxseeds: 5g
2 tbsp of Psyllium Seeds: 8g
¼ cup of sunflower or sesame seeds: 3g

While Jeannie recommends nuts as part of a healthy diet, for the sake of increasing fiber alone, she suggests seeds. Seeds are generally lower in calories and higher in fiber.

3.) Simply Switch to Whole Grains

Chances are you’re probably eating bread and pasta. But if you’re not eating whole-grain versions, you may want to make the switch. “It takes nothing other than just buying a different product at the grocery store,” Jeannie says. Below is a general breakdown of different grains and their fiber content.^6,7 As discussed, be sure to check the nutritional label to verify that the products you’re buying actually have enough fiber.

Bread (per slice)
White: 0.6g
Wheat: 1g
Pumpernickel: 1.7g
Rye, Multigrain, and Whole Wheat: 2g
100% Whole Grain: 3g

Pasta (1 cup)
Spaghetti: 2.7g
Whole Wheat Spaghetti: 5g

Rice and more (1 cup)
White Rice: 1.7g
Brown Rice: 3.5g
Quinoa: 5g
Barley: 6g
Lentils: 16g

Do you eat mostly white bread? Switching to 100% whole grain will give you about five times more fiber per slice! Jeannie recommends Dave’s Killer Bread and Schmidt’s Old Tyme 647 Bread.
If you love traditional spaghetti, switching to a whole wheat variety will add almost twice as much fiber per cup!
Switching from white rice to brown rice will provide an extra boost of fiber. To ramp things up more, try lentils!

Dress it up!

Plenty of high-fiber foods also work well as toppings to what you already eat. Try out some of these combos below for inspiration:

Salads: Dress up your salad with your choice of fruit, seeds, and nuts. Replacing some or all of your greens with raw kale will also increase its fiber content.

Sandwiches: Enhance flavor with avocado or hummus. Add your choice of fruit on the side for even more nutrients.

Pasta: Whether you serve them on the side or add them directly to your dish, broccoli, tomatoes, and zucchini are great complements to pasta.

Stir fry: Increase the fiber content of your stir fry with your choice of beans or legumes. Serve over brown rice for even better results.

Feeling breakfast?
1 cup of cooked oatmeal provides 4g of fiber. Top it with fruit for even more!

In Conclusion

Overall, increasing fiber may seem difficult at first, but it can be done easily with simple changes. If you’re ready to eat more fiber, Jeannie strongly urges you to start gradually; otherwise, you may experience unpleasant symptoms, such as flatulence and digestive discomfort. She suggests adding two or three grams of fiber every couple of days, slowly increasing until you meet the recommended amount. It’s also wise to increase your hydration as you increase fiber intake; drinking more water will help the fiber move more comfortably through your digestive system.

This article has been reviewed by Jeannie Versagli, RD, LDN. Jeannie is a Registered Dietitian with the Academy of Nutrition and Dietetics, a national professional organization, and is licensed in nutrition with the State of Delaware.

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