What Is a High-Fiber Diet?

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A high-fiber diet has several benefits, including helping with weight loss. While fiber is a carbohydrate, it is not easily digestible. It adds bulk to satisfy your feeling of fullness after a meal while not boosting your blood sugar or adding calories. You can enjoy a bigger portion of many high-fiber foods and still keep your calories under control. Also, fibrous foods often need chewing, which is another factor that leads to feeling satisfied from eating.

What Experts Say

"High-fiber diets are great for so many reasons—they keep you regular, can help with weight loss, are heart healthy, and are great for your gut and reducing overall inflammation. If you don’t eat a lot of fiber currently, slowly add it to your diet so that it’s well tolerated."
Kelly Plowe, MS, RD

Background

While not a commercial plan designed for weight loss, high-fiber diets have been promoted for years for their health benefits along with their potential to assist in weight loss. The three most important kinds of dietary fiber include:

  • Insoluble: This fiber comes from the walls of plant cells and it doesn't dissolve in water or ferment in the colon like soluble fiber. It is found in whole grains, the skin of fruit that grows on trees, and many green vegetables. This is the kind of fiber that helps with digestive health and regularity.
  • Soluble: This fiber is found in most plants, but especially in legumes and beans, root vegetables, many fruits, and some grains, such as oats and barley. "Good" bacteria in the colon use this kind of fiber as a food source, and it may help control blood sugar levels in people with diabetes.
  • Prebiotic: This is a type of soluble fiber (called inulin or fructan) that is found in asparagus, onions, garlic, leeks, bananas, and some root vegetables, as well as in certain grains.

How It Works

Fiber comes only from plants, so you will need to include plant sources in your diet to get enough fiber. The good news is that many plant sources are also nutrient-dense in vitamins, antioxidants, and phytonutrients that are beneficial for your health. When possible, get your fiber from food sources rather than using fiber supplements. Products promoted as "fiber-fortified" may also contain added sugars and other artificial ingredients, so check the nutrition label carefully.

What to Eat

Compliant Foods

  • Whole fruits

  • Vegetables

  • Whole grains

  • Legumes

  • Nuts and seeds

Non-Compliant Foods

  • Clear fruit juices

  • Refined flours

blackberries
Verywell / Alexandra Shytsman

Whole Fruits

Fiber is especially found in the skins, seeds, and membranes of plants, so it's best to enjoy as much of the plant as is edible. Juices often have little fiber, and peeling will discard valuable fiber.

One cup of raspberries or blackberries has 8 grams of fiber and only 64 calories—that makes them some of the most fiber-dense foods in the world. Most kinds of fruit pack a bunch of fiber, but raspberries and blackberries beat most others (with double the fiber of blueberries and strawberries). Add them to your yogurt bowl or snack on them straight.

Other fruits that are very high in fiber include passionfruit, guavas, and pomegranate seeds (rather than juice). Dried fruits such as raisins, dates, and figs are high in fiber but are also high in sugar. They make great fiber additions to oatmeal but consider the portions.

Brussel sprouts
Verywell / Alexandra Shytsman

Vegetables

As a rule of thumb, richly colored veggies—carrots, beets, parsnips, brussels sprouts—are high in fiber. Vegetables are a great way to super-size meals and give you a big portion without a big calorie count. Using high-fiber veggies makes the meal even more satisfying.

For breakfast, include veggies such as onions, green peppers, and spinach with your eggs for a fiber-rich but low-calorie and high-protein frittata.

You can enjoy a snack of high-fiber hummus dip paired with raw veggie dippers such as carrots, red peppers, green peppers, broccoli, and celery. Hummus can be high in fat, but you can slim it down by making it yourself from canned or boiled chickpeas (garbanzos) and limiting the oil added.

Breakfast made of oatmeal with apples, honey and cinnamon
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Whole Grains

Choose whole grains over refined ones to boost fiber intake. For example, select 100 percent whole wheat bread instead of white bread (or wheat bread that isn't made from 100 percent whole wheat).

Oats are a fantastic way to get the fiber you need, but not all oatmeal is created equal. Start with old-fashioned dry oats—a half-cup serving has four grams of fiber. To make it extra filling, prepare it "growing oatmeal" style with twice the liquid and double the cook time. That'll give you a gigantic portion. For even more fiber, top it off with tons of fresh fruit.

Pinto beans
Verywell / Alexandra Shytsman

Legumes

Beans are an amazing food to add to your diet. Not only are they naturally high in fiber, but they’re also packed with protein. Black beans, garbanzo beans, and kidney beans are all-stars—a half cup of any of them has around 6 grams of fiber. And they’re so versatile. You can use black beans to make veggie burgers, Mexican stew, and even chocolate cake. Edamame is a great snack that has 4 grams of fiber in 1/2 cup of shelled beans.

Split pea and lentil soups are made mostly of legumes. Add bulk and flavor with pearled barley (a high-fiber whole grain) and satisfying, high-fiber veggies like butternut squash and potatoes. Just watch your portion sizes and check the stats, because dense soups can be high in calories. As well, homemade soups can be made lower in the fat and salt found in the soup at the supermarket.

Chia seeds
Verywell / Alexandra Shytsman

Nuts and Seeds

Chia seeds and ground flaxseeds pack 3 grams of fiber per tablespoon. They are easy additions to smoothies, oatmeal, yogurt, or salad dressings. Plus, they are rich sources of omega-3 fatty acids. Ground flaxseeds add a nutty flavor and you can use them in baking or breading. Chia seeds can also be used to make chia pudding, which is a satisfying breakfast or dessert.

Nuts and roasted pumpkin or squash seeds make a great snack food that you can season with autumn spices like cinnamon and nutmeg or savory spices like curry powder or cayenne pepper. You will get 4 grams of fiber in only 12 pumpkin seeds (the whole seed, not the unshelled kernels). Just be aware that nuts and seeds do contain fats.

Fruit Juices

Clear fruit juices, like grape and apple, contain very little fiber. It's better to eat the whole fruit, with skin when possible, rather than juice it. Orange juice with pulp does contain fiber, and of course prune juice is a very good source of fiber as well.

Refined Flours and Grains

Stick with whole grains as much as possible to boost your fiber intake.

Recommended Timing

You can add fiber to any meal or snack to increase your overall daily intake. Just do so gradually so that your digestive system can tolerate it.

Resources and Tips

Don't worry too much about getting all the different kinds of fiber (soluble and insoluble). As long as you are eating a diet that is rich in fiber overall, you will be getting the benefits.

Modifications

Because of its effects in the colon, fiber can be helpful for people with some digestive conditions, but not others. For example, people with irritable bowel syndrome (IBS) could benefit from soluble and prebiotic fiber, added slowly to their diet. If you have any of these kinds of conditions, consult your doctor to determine how much fiber you should be consuming, and whether or not fiber supplements would be helpful or not.

Pros and Cons

Pros

  • Bowel regularity

  • Heart health

  • Weight loss

  • Cancer prevention

Cons

  • Intestinal gas

  • Abdominal bloating

Pros

Bowel Regularity

Fiber helps the colon do its job well, so it produces stool that is bulky, but also soft enough to pass comfortably. So consuming dietary fiber helps keep bowel movements regular and prevent constipation, hemorrhoids, and maybe even colon cancer.

Weight Loss

Dietary fiber helps promote weight loss because it is filling while also being low in calories. And when you eat more high-fiber foods, you have less room in your diet for foods that are not as nutrient-dense, such as refined carbohydrates. Fibrous foods can also be a good source of lean protein, instead of higher-fat sources like red meat. One study published in 2015 found that simply focusing on adding more fiber to your diet can lead to weight loss almost as great as following a strict American Heart Association diet.

Heart Health

Soluble fiber helps improve blood cholesterol levels and blood pressure, and can promote weight loss. All of these are risk factors for heart disease. Research published in 2016 shows that overall, dietary fiber helps lower the risk of death from heart disease.

Cancer Prevention

Research reviewing a series of studies was published in 2016 and found that dietary fiber lowers the risk of cancer death as well. In particular, it may have an effect on colon cancer because of the way it helps the digestive system function.

The benefits of a high-fiber diet are many and far-reaching. And the drawbacks are minor and easy to overcome.

Cons

Intestinal Gas

High-fiber foods, especially beans, have a reputation. Yes, it's true that they can cause or worsen intestinal gas. It may be embarrassing, but it is harmless and a sign that the good bacteria in the gut are doing their job. And prebiotic fiber can actually help make that gas less smelly.

Abdominal Bloating

Both gas and bloating can result from consuming too much fiber, too fast. So if you plan to start a high-fiber diet, do it gradually. Add fiber a little bit at a time so that your digestive system can handle it.

How It Compares

The high-fiber diet, with its abundance of whole grains, vegetables, fruits, and legumes, is similar to several other diets known to be heart-healthy. It also aligns with current dietary guidelines.

USDA Recommendations

The USDA advises a balanced mix of fruits, vegetables, grains, protein, and dairy products. Most Americans don't get the recommended daily amount (RDA) of fiber: 22 to 28 grams for women and 28 to 33 grams for men.

Similar Diets

All of these diets are likely to be high in fiber as well as other important nutrients.

High-Fiber Diet

  • How it works: Consume foods that are a good source of dietary fiber, to get at least the RDA or more. Ideally, get all or most of your fiber from foods, not supplements.
  • Effectiveness: Research has shown that high-fiber diets can promote weight loss and other health outcomes.
  • Practicality: This informal diet doesn't require any calorie or carbohydrate counting. For some people, cooking with these high-fiber foods may be unfamiliar, and will take some time to learn.
  • Sustainability: The diet is safe and healthy to continue long-term.

DASH Diet

  • How it works: The DASH diet (Dietary Approaches to Stop Hypertension) is not a commercial weight-loss program, but an eating plan developed by medical professionals to help patients with high blood pressure. It is low in fat and sodium and high in nutrient-dense (and, often, high-fiber) foods such as fruits and vegetables, whole grains, legumes, fish, and poultry.
  • Effectiveness: Even though it is not specifically designed for weight loss, many patients do lose weight by following this plan.
  • Practicality: The diet does limit (but not ban) sweets, red meat, and processed meats, along with greasy foods. So people who are eating lots of those foods need to make adjustments that could be difficult. And portion control is important. But no special foods or supplements are required.
  • Sustainability: This is also a healthy way to eat for lifelong wellness.

Mediterranean Diet

  • How it works: Also not a commercial plan, the Mediterranean Diet is based on the traditional diet of people in the Mediterranean region who are noted for their longevity. It stresses fruits, vegetables, whole grains, fish, and olive oil.
  • Effectiveness: Although it is not designed for weight loss, many people do lose weight if they adopt this style of eating.
  • Practicality: There are no strict rules or guidelines on this plan. Simply eat the Mediterranean ingredients as much as you can. Limiting sugar and red meat might be hard for some followers.
  • Sustainability: Eating this way could have long-term benefits.

Whole Foods Diet

  • How it works: On a whole foods diet, followers avoid eating any refined or processed foods. They stick with whole grains and simple ingredients, especially fruits and vegetables.
  • Effectiveness: This is not a formal weight-loss plan, but cutting out refined foods and added sugars and fats can promote weight loss.
  • Practicality: This can be a difficult (and costly) diet to follow faithfully because it requires a lot of food preparation and cooking, since no convenience foods are allowed.
  • Sustainability: This is a healthy way to eat, but it can be taken to extremes. Not all processed food is bad for you.

A Word From Verywell

The evidence is convincing: Adding more fiber to your diet is a smart way to improve your health and, most likely, lose weight.at the same time. Just use caution if you have any digestive health concerns, and always add fiber to your diet gradually instead of all at once.

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