The 411 on Fiber
Fiber is a crucial component of an overall healthy diet. Now, I know some associate fiber as something important only to those who have troubles with passing bowel movements, and for those that do believe this, they are partially correct! Fiber plays a big role in digestive health in general, but it's important to note that almost everyone can benefit from incorporating it into their diet regularly and that it has reported benefits to many other aspects of our health. How, you say? Let's dive in.
What is fiber?
Simply put, fiber is a type of carbohydrate that we cannot digest that comes from plant sources. For the most part, fiber passes through our digestive tract without being digested or absorbed, then leaves the body through bowel movements. As it passes through our digestive tract, it helps us out in a variety of ways. Before we talk about that, let's go over the two main categories of fiber: soluble and insoluble fiber.
Soluble fiber is soluble in water and forms a gel-like substance in your digestive tract. This type of fiber is beneficial for being able to lower blood cholesterol and stabilize blood sugar levels. Common foods that contain soluble fiber include oatmeal, apples, carrots, beans, seeds and barley, to name a few.
Insoluble fiber does not dissolve in water. This type of fiber increases bulk in your stool and allows for better movement of food products through your digestive tract. Thus, this type of fiber is often beneficial for those struggling with constipation or bowel movement irregularity. Some food sources of insoluble fiber include whole grains, root vegetables, nuts and seeds.
While I have listed out common food sources of both categories of fiber, many foods have a mixture of both soluble and insoluble fiber. Therefore, variety is key in order to ensure adequate consumption of both types.
Aside from promoting bowel regularity, stabilizing blood sugar levels and preventing or relieving constipation, fiber supports our health in a few other ways. Fiber has the ability to keep you full for long periods of time. This creates the likelihood that you'll be more satisfied after eating and that you'll eat less in general on a higher fiber diet. This can ultimately help individuals achieve or maintain a healthy weight. As fiber passes through our colon, it feeds our friendly gut bacteria, also known as our gut microbiota or gut flora. Although this is the case for some types of fiber, not all fiber is created equally. The type that can easily be used by our friendly gut flora is called fermentable fiber, while fiber that cannot is called non-fermentable fiber. Again, eating a variety of high-fiber foods is key in order to ensure you are eating the types of fiber that feed your gut flora as well. Diets high in fiber have also been shown to be protective against the development of several chronic diseases, such as cardiovascular disease, type 2 diabetes and certain cancers (1).
What are the best sources of fiber and how much should we consume?
Fiber is found in plant sources. Common plant-based foods that are high in fiber are fruits, vegetables, whole grains, nuts, seeds, beans and other legumes. When foods are highly processed or refined, with examples such as fruit juices, white breads and pastas, and non-whole-grain cereals, they lose most of their fiber content and all of the benefits that come along with it. Therefore, it is best to be mindful of your intake of refined carbohydrates versus whole carbohydrate-containing foods. With that being said, a general recommendation by the USDA Dietary Guidelines for Americans is to make sure half of your daily grains are whole grains in order to optimize fiber intake (2). Recommendations for daily fiber intake vary by age and gender. The overall recommendation for daily fiber intake for adults, as established by the The Dietary Guidelines for Americans, is:
Women under 50: 25-28 g/day
Women over 50: 22 g/day
Men under 50: 30-33 g/day
Men over 50: 28 g/day (3)
The average American consumes roughly 15-17 grams of fiber per today, which is below the general recommendations established by public health organizations (4). With low-carb diets gaining popularity in the U.S., there is concern that the issue of low fiber consumption among Americans may worsen.
Some tips on how to increase your fiber intake
Choose high-fiber breakfast options. Breakfast is an easy mealtime to incorporate more fiber into your day. Try opting for breakfast cereals with a higher fiber content or adding fruit to your oatmeal or blending it in a smoothie.
Try eating more whole grains throughout the day. Again, a good rule of thumb is to make sure half of your daily grains are whole grains. Now, if you absolutely love white rice instead of brown rice with certain dishes, then go for it! The goal is to create general healthy eating habits, and eating foods you enjoy in moderation, whole grain or not, is also very important. We don't want to feel deprived after all! If you want to consume more whole grains throughout the day, try swapping refined, white bread for whole wheat bread, or refined pasta for whole wheat pasta for example.
Eat more fruits and vegetables. Fruits and veggies are naturally high in fiber, as well as many important vitamins and minerals.
Show your snacks some love. Have whole fruit, veggies sticks, nuts and whole-grain crackers on hand for snacks that are easy to assemble and high in fiber.
I hope this article provided a good introduction to the reasons why we should celebrate fiber! As always, if you want to learn how to apply this information in your life or have any questions or concerns about your personal health and eating habits, it is best to consult with your own health care provider. If you are looking for a registered dietitian to work with, click here to learn more about working together.
Until next time!