• Can today’s food trends be cutting this important nutrient?

    When people tell me that they are eating low-carb, keto, paleo, Atkins, carnivore (yup, that’s a thing), or whatever is the latest anti-carb diet, the dietitian in me tends to go where the mind of a dietitian goes in this situation: “when was the last time you had a decent bowel movement?” I don’t usually say that out loud… sometimes I do.

    I even had someone once tell me that he though “carbs were the devil.” No really. As if there aren’t worse things in the world than carbohydrates?  

    So, when people tell me that they don’t “eat carbs” I get concerned because any food that is plant-based or plant-derived has carbs.

    Carbs, or carbohydrates, include sugars, starches, and fibers.

    All sugars are carbs, but not all carbs are sugars.

    All starches are carbs, but not all carbs are starches.

    All fibers are carbs, but not all carbs are fibers.

    All sugars in the diet will be broken down and converted to glucose and used as fuel for the body immediately or for future use (as glycogen). Excess will be stored if not used.

    All starches in the diet will be broken down and converted to glucose and used as fuel for the body immediately or for future use (as glycogen). Excess will be stored if not used.

    And, yes, I know that was practically the same sentence, but that is what both sugars and starches will do. It just takes longer for the starches to break down than the sugars to break down.

    Then there is fiber. Fiber is a type of carbohydrate, but humans just don’t have the enzymes to break down fiber to be broken down to glucose and used as fuel.

    But just because we can’t break it down doesn’t mean this is an irrelevant nutrient. No way.

    Fiber is natures broom to sweep out the “dirt” in the body.

    I tend to refer to fiber as “natures broom.”

    If you know much about fiber, then you may have heard of soluble and insoluble fiber – both with benefits. But we also have functional fiber which is a fiber that is added to foods.

    I used to say that fiber is only found in plant foods. Now I say, fiber is only found naturally in plant foods. I’ll get to that.

    Dietary Fiber vs Functional Fiber

    Fiber found naturally in foods is technically considered dietary fiber. Most people will just refer to this as fiber rather than dietary fiber. Why would this matter? Because some fiber found in foods today is added from natural sources but may not be naturally be found in those foods. Keep reading and hopefully this will be clearer.

    Soluble Fiber, a type of Dietary Fiber

    Soluble, meaning is dissolves in water, will have an effect on your blood health. Blood, liquid, soluble fiber.

    So, this will help with managing blood glucose (sugar) levels and blood cholesterol levels.

    If people have more fiber in their diet, despite being in a carbohydrate, it can help keep blood glucose levels manageable. Same with blood lipids, like triglycerides and low-density lipoproteins (LDL-cholesterol). That’s a good thing.

    You may have heard that oats, oatmeal and beta-glucan can help with heart health. This is the soluble fiber that is helping here. Oats have a good amount of soluble fiber known as beta-glucan. But oats aren’t the only source of soluble fiber.

    Other foods that have soluble fiber: beans and peas, fruits and veggies, whole grains, and nuts and seeds.

    Insoluble Fiber, the other type of Dietary Fiber

    Insoluble, meaning that it does not dissolve in water, will be mostly intact as it travels through the gut.

    This is the kind of fiber that helps with regularity and sweeping out the gunk in the gut, mostly the large intestine. And, as I tend to tell people, it moves things out in a timely manner.

    Good sources of insoluble fiber: beans, fruits, veggies, whole grains, and nuts… Sounds familiar?

    Fiber is in any food of plant origin including fruits, whole grains, vegetables, nuts, seeds, and beans.

    Really, when I counsel clients on increasing their fiber intake, I rarely, or never have recommended that they increase one but not the other. It tends to be a package deal of increasing dietary fiber overall. Most people need more fiber overall, not one or the other. Both have benefits, and when people increase one type, the other will also increase. No question. As long as they are getting it from their food and those foods are minimally processed plant-foods such as whole grains, nuts, seeds, beans, and of course, fruits and vegetables.

    Functional Fiber

    Here is where things get a big tricky. In a statement above, I wrote, “I used to say that fiber is only found in plant foods. Now I say, fiber is only found naturally in plant foods.”

    The reason I now say that fiber is found naturally in plant foods is because functional fiber is the kind that is extracted from plants and added to foods to either replace, boost or add fiber to them. Sometimes they are added to processed foods and other times they are added to foods that wouldn’t naturally have fiber, such as yogurt.

    If you look at the Nutrition Facts panel of a yogurt and it has fiber it is probably not from any fruit (fruit has fiber, but not so much that it would register on the Nutrition Facts label), but probably from chicory root that adds both fiber and some sweetness.

    Functional fibers are added to foods and can be extracted from natural sources or synthesized (created).

    Is there anything “wrong” with getting these functional fibers in your diet? Not necessarily, but I would always encourage people to choose whole foods or minimally processed foods with naturally occurring dietary fiber rather than more processed foods with added fiber.

    For example, I had a client who told me that she and her pre-school son would each eat a toaster pastry for breakfast, but because they were a brand that were marketed as ones with fiber in them, she felt they were a better option. While yes, there was more fiber in that toaster pastry (5 grams compared to 0.5 grams), let’s be honest about this: it was still a toaster pastry.

    Additionally, some people may have GI upset or distress with some of these functional fibers, they may not even make the connection that it is related to this ingredient or ingredients. So, if you find that you had a day close to the bathroom, maybe take a look at you ate a couple of hours ago.

    How do I know if I am getting enough?

    Unless you start tracking, there isn’t really a way to know for sure how much you are getting day to day.

    How do you know if you are getting enough fiber in your diet?

    The classic answer: if you get your recommended amounts of fruits, veggies, whole grains, nuts, and seeds, you will get close if not be on target. You could even surpass your recommendation.

    You can get too much, but if you are using only food, not supplements, then I won’t be worried.

    But please, ease into increasing this fiber intake. Going from under 10 grams a day to aiming for 25 grams the next day can be a bit painful. Let your body adjust by adding one or two more servings of fruits or veggies a day for a week or more.

    Oh, and how much to you need? In general, women need 25 grams/day, men need 35 grams/day. However, there is another way to estimate fiber needs based on calorie needs. We estimate that adults need 14 grams fiber for every 1,000 calories.

    So, if someone needs 1,800 calories per day then their fiber recommendation is 25 grams a day (14 x 1.8) and is someone needs 2,500 calories per day they need 35 grams a day (14 x 2.5). It comes out similar, or really exactly the same, but keep in mind that everyone’s calorie needs are different.

    Fiber is required to be listed on the Nutrition Facts panel as a sub-set of carbohydrates. The total fiber listed includes soluble, insoluble and any functional fiber that may be added to the food.

    Supplement? Or Just eat an apple?

    Sometimes people will choose a fiber supplement to increase their fiber intake. There are plenty to choose from, and I won’t make a recommendation to do so without knowing the individual and their specific health concerns and issues.

    One cup of fresh raspberries has 8 grams of fiber.

    But let’s take a look at the numbers: a serving/dose of many popular fiber supplements has 3 – 6 grams of fiber. A medium banana has 3 grams of fiber, a medium apple has 4 grams, one cup of cooked oats has 4 grams, and one cup of raspberries has 8 grams.

    There are many foods, loaded with other nutrients in addition to their fiber content, that easily provide fiber. No need to use a supplement, just add serving of fruit or whole grain and it equals the fiber supplement dose. And it is usually less expensive.

    Fiber and (Colon) Cancer Connection

    People who have a diet high in fiber have lower risk of colorectal cancer and certain other cancers.

    This is not necessarily to say that fiber itself is the magic that reduces the risk, but that they are eating foods that are high in fiber. Those foods have other components including vitamins, minerals, antioxidant nutrients and phytochemicals (naturally occurring plant chemicals) that are very likely cancer-protective.

    We do not see the same result with fiber supplements. So, stick with the plant-based, minimally processed foods to get the best benefit.

    As always keep in mind that plant-based means that this is the basis of the diet. It does not necessarily mean that one needs to avoid or eliminate animal-based food. See more about that in the blog post, Plant-Based Whole Foods Diet – What Does That Mean? 

    Resources and References:

    For more about the fiber and cancer connection and how to transition to more fiber, see the American Institute for Cancer Research: Making it work for you and Making the transition to add more fiber

    The American Cancer Society ACS Guidelines on Nutrition and Physical Activity for Cancer Prevention, Common Questions About Cancer and Diet – Fiber

    For more information about fiber and recipes see the FiberFacts.org site that is part of the Calorie Control Council.

    Fiber content of food retrieved from CalorieKing.com

    Fiber supplement content collected from individual supplement websites.