How to Increase Fiber in Your Diet WITHOUT all of the Digestive Upset

Not eating enough fiber is a very common reason for people to have digestive issues.  Our minds first race to constipation, a very common side effect of not eating enough fiber.  However, even if you’re not constipated, you could still have consequences from not getting enough fiber in your diet.  And that’s because fiber has many other roles, not just the relief of constipation.  In fact, even people who are diarrhea-prone may be suffering due to a lack of a certain type of fiber.  That’s because fiber has functions other than providing bulk for the relief of constipation, such as feeding our microbiome and helping to lower cholesterol and blood sugar.

Most Americans eat half as much fiber as our ancestors did.  It is estimated that those eating the typical American diet in this day and age get an average of 14-15 grams of fiber a day, while in the 1850’s it is estimated that our American ancestors ate 25-30 grams of fiber a day, which just so happens to be the amount determined to be ideal for people.  An average-sized woman should be eating about 25 grams of fiber a day and an average-sized man should be eating about 30 grams of fiber a day.

While we all know that fiber is good for us, for many, increasing fiber in their diet results in digestive symptoms such as gas, stomach cramping, and bloating.  So, they just stay away from it, missing all of the health benefits of fiber.

Let’s break down this topic of fiber a little bit more so that if you’re one of those people who don’t do well with increased fiber, you’ll know exactly how you can gradually increase the fiber in your diet with the right type of fiber, in the right amount, and do it the right way so that digestive issues don’t arise.

Types of fiber

There are two types of fiber—insoluble and soluble—and the tricky thing is that most foods contain both types.  This makes it difficult for those who cannot handle the insoluble fiber (which increases bulk and relieves constipation) to get enough of the soluble fiber (which does not).

Insoluble fiber

Insoluble fiber does not dissolve in water or gastrointestinal fluids and remains more or less unchanged as it moves through the digestive tract. Because it is not digested at all, insoluble fiber is not a source of calories.

Benefits of insoluble fiber

Insoluble fiber is a great relief for constipation as it adds bulk to the stool and helps food pass more quickly through the stomach and intestines.  It helps to lower cholesterol and make you feel full, which can lead to eating less food and thus lose some weight.  It is also believed to reduce the risk of colorectal cancer.  Insoluble fiber is found in beans, bran, and whole grains as well as most fruits and vegetables.

Soluble fiber

Soluble fiber, on the other hand, does dissolve in water and gastrointestinal fluids. As it dissolves, it is transformed into a gel-like substance, which is digested by the bacteria in our large intestine, releasing gases and a few calories.  Soluble fiber is found in foods such as brussels sprouts, lima beans, black beans, oat bran, many fruits, and flax seeds, though these foods contain insoluble fiber as well. Of special note is psyllium, which is very high in soluble fiber, about 70 percent, and the remainder is insoluble fiber.

Benefits of soluble fiber

Soluble fiber is fermented in our large intestines by beneficial bacteria, producing short-chain fatty acids (SCFA).  These SCFA are the main energy source of our colonocytes, the cells that make up our gut lining.  I think of them as our little gut housekeepers, maintaining the health of our gut lining.

Soluble fiber nourishes and stimulates the growth of lactobacilli and bifidobacterium in our intestinal microbiome, which reduces disease-causing bacteria such as Clostridium difficile, Klebsiella, and Enterobacter.

Soluble fiber also helps to bind bile acids and regulate cholesterol levels and blood sugar levels.

With so many benefits, it’s easy to see that we need both types of fiber in our diet.

How to get more fiber in your diet:

Even people with SIBO and IBS can benefit from fiber, but they must start slowly with a little bit of the soluble type of fiber and gradually increase their soluble fiber intake.  Soluble fiber is also beneficial for those with Crohn’s disease, hiatal hernia, and peptic ulcer.  If they work on quenching the inflammation in their belly at the same time, as I do with my clients who do food sensitivity testing, they are very soon eating a healthful, fiber-rich diet without digestive upset!

Because people with these conditions typically cannot handle insoluble fiber, I recommend supplementing with partially hydrolyzed guar gum (PHGG), which contains only soluble fiber first, while continuing to eat a low-fiber diet.  Then, as we work on reducing the inflammation in their gut and as their digestive system gets used to the soluble fiber, they can add foods higher in insoluble fiber to their diet as their digestion allows.

My favorite supplement for PHGG is Tomorrow’s Nutrition SunFiber, which can be ordered in my online FullScript store.

While increasing your soluble fiber intake (even with PHGG), it’s best to start slowly and build up gradually over a period of 1-3 weeks to avoid the bloating, cramping and gas that often ensues from increasing fiber intake too quickly.  It’s also necessary to drink plenty of water so that the soluble fiber can swell, become gel-like, and do all the wonderful things that it does!

Once you are able to handle a full dose of PHGG, you can begin to slowly increase the amount of soluble fiber you get from food, remembering that food contains a mix of soluble and insoluble fiber, so you’ll want to first add in foods that contain a larger proportion of soluble vs insoluble fiber.  Later, you can begin increasing foods that are higher in insoluble fiber.

Foods high in soluble fiber include:

• Black beans
• Garbanzo beans
• Lentils
• Edamame
• Lima beans
• Barley
• Chia seeds
• Flax seeds
• Sunflower seeds
• Oats
• Hazelnuts
• Brussels sprouts
• Broccoli
• Avocados
• Carrots
• Pears
• Apples
• Raspberries
• Blackberries
• Artichoke hearts
• Sweet potatoes

This is by no means an exhaustive list.  Beans and legumes of all types, whole grains, as well as most fruits and vegetables, contain fiber (both soluble and insoluble), but the ones listed above are higher than most other foods in soluble fiber.

Foods high in insoluble fiber include:

• Wheat bran and wheat germ
• Oat bran
• Beans, lentils and legumes of all kinds
• Berries
• Whole grains
• Turnips
• Green peas
• Okra
• Spinach
• Radishes
• Rutabaga
• Coconut (grated flakes or flour)
• Cocoa
• Apples with skin
• Pears with skin
• Flaxseeds
• Avocado 
• Sunflower seeds
• Potatoes and sweet potatoes 
• Dried apricots, prunes, raisins, dates and figs
• Almonds
• Walnuts
• Passionfruit
• Popcorn

I realize there are some foods (such as flaxseeds) on both lists.  That’s because there are both types of fiber in foods, and the foods in both lists are good sources of both.  When you are increasing your soluble fiber, go easy on these foods!

I recommend soaking grains and beans a certain way before they are cooked to make the minerals in these foods more absorbable and to make the grains and beans easier to digest.  Download my FREE Guide to Soaking Beans today!