If you’re dealing with a constipated toddler, you’ve probably heard how important fiber is for kids. Many times that’s all the information that parents are given. You may not have been told where you can get fiber or that you can actually have too much fiber.
Many people refer to fiber as roughage because it comes from plant foods or bulk because it’s something that our body doesn’t digest and adds bulk to our stools.
What is fiber?
Fiber is a carbohydrate found in plants that our bodies can’t digest. Some fibers, fermentable, act as the food for our gut bacteria. However, other fibers, nonfermentable, pass through our gut completely undigested and just act as bulk to make it easier to pass.
Naturally occurring plant fibers include cellulose, hemicellulose, lignans, beta-glucans, guar gum, inulin, oligofructose, oligosaccharides, fructo-oligosaccharides, pectin, and resistant starches. Fibers that you may see added to foods include psyllium, polydextrose, polyols, inulin, oligosaccharides, pectin, resistant starch, and gums.
Within the broad category of fiber, there are 2 subcategories: soluble and insoluble. While the 2 types do have different purposes, many foods contain a blend. For most people, focusing on getting adequate fiber is more important than focusing on which type of fiber they are consuming.
We can find soluble fiber in foods like oats, beans, peas, and fruit. It is soluble, meaning it absorbs water. Some of the soluble fiber is broken down by our gut bacteria, which is what we refer to as prebiotics. Soluble fiber is associated with lowering cholesterol levels and stabilizing blood sugar levels (1). It can slow down the rate of digestion.
Beta glucans, inulin, oligofructose, oligosaccharides, fructo-oligosaccharides, pectin, resistant starch, and guar gum are soluble and fermentable. Inulin, oligofructose, oligosaccharides, and fructo-oligosaccharides have been known to cause bloating and/or stomach upset to those sensitive to them like people with irritable bowel syndrome. (2)
Psyllium is soluble, but nonfermentable. It holds onto water and softens and bulks the stool. Psyllium is an ingredient in over the counter laxative medications due to its laxative effects.
Wheat bran, vegetables and fruit skins contain insoluble fiber. It does not absorb water. Insoluble fiber can help with constipation or irregular stools because it is associated with increasing the bulk of your stool. Cellulose, hemicellulose, and lignans are insoluble fibers that can have a laxative effect.
What does fiber do?
Fiber can add bulk to your stool. This can be helpful because a bulkier stool can be easier to pass. It can also help to solidify water stools because it can absorb water and add bulk to the stool.
Some sources of fiber act as prebiotics which are the food for the bacteria in our gut. Properly feeding the bacteria can promote a healthy gut overall.
Fiber intake is also associated with good cholesterol levels, good blood sugar levels, and weight maintenance (3).
Where can you get fiber?
Plants contain fiber. Good sources include whole grains, beans, lentils, nuts, seeds, fruits, and veggies. There are also foods with added fiber. Some people report gassiness and bloating with the sources of added fiber. In general, it is recommended to choose foods with natural sources of fiber, as these foods tend to also contain many other vitamins and minerals.
The NIH has not set recommended dietary allowances, only adequate intakes. They are based on data from adults that showed that 14 grams/1000 calories was beneficial to reduce the risk of coronary heart disease (4). They also took into account that constipation is a common occurrence in children.
Human milk is used as the optimal source of nourishment for infants and there is no dietary fiber in human milk, so there was no adequate intake established for infants 0-6 months. There was not enough data to establish an adequate intake for infants 7-12 months (4).
|0-6 months||no AI set|
|7-12 months||no AI set|
|1-3 years||19 grams|
|4-8 years||25 grams|
|9-13 years (boys)||31 grams|
|9-13 years (girls)||26 grams|
Per the National Institute of Health (5)
What happens if you don’t get enough?
Many people in the US do not get enough dietary fiber. Low fiber intake is associated with constipation and other issues such as hemorrhoids. It is also associated with obesity, heart disease, diabetes, and bowel cancer (6).
Can you get too much?
There is no tolerable upper limit set for fiber, however you can get too much. This is a real concern for vegetarian children especially. Fiber can interact with some absorption of nutrients. It can also lead to a feeling of satiety leading to kids not eating as much.
When increasing the amount of fiber in the diet, it’s also important to make sure that you’re getting enough fluids and that you increase fiber gradually. Rapidly increasing fiber can lead to gastrointestinal discomfort. Too much fiber without enough fluid can exacerbate constipation.
For young kids who follow a plant based diet, it’s often recommended to offer a blend of both whole grain and non whole grain foods to help limit the amount of fiber. This is because many of the protein sources these children eat also contain fiber.
Fiber Rich Foods for Kids
- Navy beans
- Nut butters
- Pinto beans
- Pumpkin seeds
- Sunflower seeds
- Veggie burgers
- Whole wheat bread
- Whole wheat pasta
- Winter squash
There are a lot of foods with added fiber available. When possible, try to choose foods with naturally occurring fiber, as those foods tend to also contain other vitamins and minerals that our bodies need.
Krystyn Parks is a Registered Dietitian and Lactation Consultant who specializes in feeding children. She has a Master’s Degree in Nutritional Science from California State University Long Beach. She is an International Board Certified Lactation Consultant and has been registered with the Commission on Dietetic Registration since 2013.