Adding fiber is a relatively simple way to eat a healthier diet. Here’s how.

Jan. 26, 2024
Woman filling a jar with oats. People should try to get fiber through diet and food rather than through supplements or fiber gummies.
There are many whole foods that contain fiber. People should try to get fiber through diet and food rather than through supplements or fiber gummies. Photo: Getty Images.

Are you trying to add more fruits and vegetables to your diet? Or are you trying to lose some weight, adopt a healthier lifestyle, improve your gut health or boost your heart health? A simple adjustment that could make a big difference is adding more fiber to your diet.

You might think that carbohydrates are bad for you. But fiber is an essential carb that’s great for your health. Just take a gradual approach as you add more fiber to your diet so your body can adjust.

To understand the best ways to add fiber to your diet and to provide answers to common questions about fiber, we consulted with Alex Olson, a registered dietician and certified diabetes care and education specialist who supports patients at UCHealth Diabetes and Medical Nutrition Therapy – Printers Park in Colorado Springs.

Olson specializes in helping diabetes patients eat healthier diets. The same advice she gives to her diabetes patients can benefit everyone. Now is the perfect time to get started and add more fiber to your diet.

What is fiber, and what foods contain it?

Fiber is a natural carbohydrate that is found in fruits, vegetables, whole grains, legumes, nuts and seeds.

There are two types of fiber: soluble and insoluble.

According to experts at the U.S. Centers for Disease Control and Prevention (CDC), here’s what they do:

  • Soluble fiber dissolves in water and forms a gel-like substance in the stomach, which slows down digestion. Soluble fiber helps control your blood sugar and cholesterol, which can help prevent or manage diabetes complications. Soluble fiber is found in apples, bananas, oats, peas, black beans, lima beans, Brussels sprouts, and avocados.
  • Insoluble fiber does not dissolve in water and typically remains whole as it passes through the stomach. It supports insulin sensitivity and helps keep your bowels healthy to keep people pooping on a regular basis. Insoluble fiber is found in whole wheat flour, bran, nuts, seeds, and the skins of many fruits and vegetables.

Some foods have both soluble and insoluble fiber.

“Depending on the type of bean, some have a 50-50 split,” Olson said. “And oatmeal has both insoluble and soluble fiber.  It’s easy to add high-fiber foods to your oatmeal, like berries and shaved almonds.”

What foods should I eat to add more fiber to my diet?

  • Vegetables, especially high-fiber choices like Brussels sprouts, potatoes, carrots, cucumbers, broccoli and squash.
  • Nuts and seeds, including chia and flax seeds.
  • Beans and other legumes.
  • Whole grains like whole wheat bread, oats, barley and wild and brown rice.

What are some simple tips for getting more fiber in your diet?

  • Eat whole fruits rather than drinking fruit juices.
  • When you eat fruit and vegetables, eat the skins since they contain a lot of healthy fiber. Just wash foods like peaches, pears, apples, potatoes and carrots but don’t cut off the skins before eating them.
  • Add nuts, seeds and beans to other foods like soups, salads and stews.

Why should people consider adding more fiber to their diets?

Very few people eat enough fiber, Olson said.

One of the reasons that many people don’t eat enough fiber is that we get distracted by fad diets, including low-carb and keto diets.

“The keto diet eliminates many carbohydrates that are the sources of healthy fiber. Fiber is the structural part of plants. It’s not found in any animal products,” Olson said. “The keto diet is a low-carb, high-fat diet. If you do a diet like that, you’re eliminating a food group that has a lot of benefits.”

According to CDC health experts, fiber boosts our health in the following ways:

  • Fiber helps control blood sugar. Since it takes time for our digestive systems to break down fiber, foods that are rich in fiber don’t cause spikes in blood sugar the way other foods do.
  • Fiber protects the heart. Fiber prevents your body from taking in some fat and cholesterol, lowering your triglyceride and cholesterol levels to help reduce your risk of heart disease.
  • Fiber helps with gut health and keeps our digestive systems clean and healthy.
  • Fiber helps fill us up and can help with weight loss or weight management. Since fiber can’t be digested, it moves slowly through the stomach, making you feel fuller for longer. And many foods high in fiber tend to be low in calories, which can help with weight loss.

How much fiber are we supposed to get each day?

The recommended amount of fiber that adults are supposed to get is about 25 to 30 grams per day, Olson said.

In an ideal world, we want to get at least 5 to 10 grams daily of soluble foods like beans, squash, Brussel’s sprouts, oats and chia seeds.

You don’t necessarily need to worry too much about specific foods or exactly how much soluble or insoluble fiber you are eating to eat a healthy diet. Instead, focus on boosting high-fiber food groups in your diet, like fruits, vegetables, legumes, seeds and nuts. Chances are, you then will get enough fiber.

“I add beans to soups, salads, casseroles and chili,” Olson said.

“Another easy way to add fiber is instead of drinking fruit juice, eat a whole piece of fruit like an apple or an orange,” she said.

Also, nuts and seeds can be a great snack (in small amounts).

“They’re also great in baked goods,” Olson said. “Not only are nuts a good source of fiber, but they’re also a good source of fat.

“If you’re looking at fat consumption, we encourage people to have more unsaturated fats rather than saturated fats. Nuts are among the best options. They help with cardiovascular health,” Olson said.

The one caveat is if you’re trying to lose weight, you’ll want to be careful about portion sizes with nuts.

“A portion size of almonds is about 17. A handful is about 200 calories, so it’s very easy to overeat them. Try to find ways to add nuts into the diet, but monitor your portions,” Olson said.

Does fiber cause gas?

Yes. Fiber can cause gas, especially if you add a lot of it to your diet suddenly. Olson encourages people to add fiber gradually.

“If you’re going from 5 grams a day to 30 overnight, there might be an increase in bloating, gas and constipation. If you add fiber gradually, then your symptoms are not going to be as pronounced,” she said.

But foods that are high in fiber also can cause gas.

“There’s a category of vegetables that are called cruciferous vegetables. These are gas-producing vegetables. If you’re eating more of these, you’re going to have more gas, but that’s not necessarily unhealthy,” Olson said.

Does fiber help people lose weight? I’ve heard that some people are calling fiber a cheaper alternative to popular new weight loss drugs. Is that true?

Eating more fiber can help people lose weight because it causes a delay in digestion, making someone feel more full or satisfied after eating a meal which in turn can decrease overeating. Fiber is also found in healthy foods like fruit, vegetables, and whole grains.

But, no, it is not correct that fiber can be an alternative to drugs like Zepbound, Ozempic and Wegovy. Certainly, fiber can slow down digestion and reduce hunger like the new weight loss drugs. But the drugs have complex impacts on hormones, certain parts of the brain, insulin production and resistance as well as the liver. So, no, it’s not accurate to say that fiber is comparable to Zepbound, Ozempic or Wegovy or a good, cheaper alternative to the newest weight loss drugs.

Can you eat too much fiber?

Not really. Fiber is healthy. Olson just reiterates her advice to ease fiber into your diet father than overdoing it if you’re trying to start a health kick or suddenly change your diet.

“Don’t automatically increase to 30 grams a day. Your digestive system wouldn’t process this well. I tell people to gradually increase fiber. And as you do, be sure to drink more water so you don’t get constipated,” Olson said.

What about fiber supplements like psyllium or fiber gummies? Do they work? Are they healthy? Should I take them?

Olson advises people to try to get fiber through diet and food rather than through supplements or fiber gummies.

“That’s the best way,” she said.

And, in general, gummy vitamins don’t work as well as other types of vitamins, especially getting your vitamins naturally through healthy foods.

“Gummy vitamins may have fewer nutrients than people are led to believe,” Olson said.

Whenever possible, get your nutrients through real food.

For people who can’t get enough fiber, a supplement would be fine.

“But fiber supplements are mostly soluble fibers. You’ll still want to consume some insoluble fiber,” she said.

Insoluble fibers help keep food moving through our digestive systems and help the gut stay clean and healthy.

“Fiber acts as a scrub brush in our arteries and digestive tract,” Olson said. “It removes plaque that builds up over time and binds to cholesterol and sugar in our gut, allowing us to excrete them.”

What is your simplest advice about fiber?

Focus on eating more fruits, vegetables, beans, legumes and whole grains. That way, you’ll get more fiber and healthy nutrients of all sorts, Olson said.

“Food is food. As long as you’re eating real (not processed) food, it will provide you with benefits,” Olson said. “We need to get away from categorizing food as good or bad and just focus on adding healthy options. If we’re more mindful and intuitive when we eat, then we don’t have to be so judgmental about what we eat.”

Any other pro tips when you’re adding fiber?

Yes! Here are some helpful ideas:

  • Canned beans are great. They’re handy and easy to use. Just rinse your beans if you’re trying to reduce your salt intake.
  • The same is true for canned vegetables. If you want less salt, you can rinse canned veggies as well to remove up to 50% of the sodium content.
  • Frozen fruits and vegetables are nutritious and easy to keep around. Add frozen berries to oatmeal or yogurt. And throw frozen veggies into soups, stews, pastas and stir-frys.

About the author

Katie Kerwin McCrimmon is a proud Coloradan. She attended Colorado College thanks to a merit scholarship from the Boettcher Foundation and worked as a park ranger in Rocky Mountain National Park during summers in college.

Katie is a dedicated storyteller who loves getting to know UCHealth patients and providers and sharing their inspiring stories.

Katie spent years working as an award-winning journalist at the Rocky Mountain News and at an online health policy news site before joining UCHealth in 2017.

Katie and her husband, Cyrus — a Pulitzer Prize-winning photographer — have three adult children and love spending time in the Colorado mountains and traveling around the world.