The goal of this series is to consider different food-related culprits to IBS symptoms, not to create food fear and food restriction. Before undergoing dietary changes, please work with a nutrition professional to ensure you are meeting your body’s nutritional needs in a healthy manner.
What is fiber anyway? Fiber is the undigestible plant matter from food that passes through the body in our stool. Essentially, it is roughage that our digestive tract can't break down and metabolize. Eating enough fiber is crucial to a well-functioning digestive system, because it serves as "food" for the bacteria in our colon - our gut microflora. Without proper nourishment (from fiber), the "good" bacteria in our colon can fail to thrive, leading to gut issues that can cause IBS symptoms, such as diarrhea, constipation, gas, bloating, intestinal cramps, and more - yuck!
A good rule of thumb is to aim for about 14 grams fiber for every 1,000 calories you eat. This means if you eat 2,500 calories per day, you'll want to get in about 35 grams fiber. However, if your calorie requirements are low and you eat about 1,200-1,400 calories per day, you'll want to make sure to get in a minimum of 21 grams of daily fiber. If you aren't close to reaching the fiber target for your calorie intake, be sure to increase your fiber intake gradually, not overnight, so your digestive system can adjust! You'll also want to increase your water intake, so your digestive system can "move things along" appropriately. Start with the fluid calculation I wrote about in my previous post, and include this tip below as well...
There are two main types of fiber - soluble and insoluble fiber - both being important for optimal digestion and elimination. Soluble fiber forms a gel when it exposed to water (it is water-soluble) and softens stool. Food sources of this stool-softening fiber include: oatmeal, green peas, oranges, beans, and milled flaxseed. On the other hand, insoluble fiber is not water-soluble and adds bulk to the stool. This fiber, in particular, can help prevent constipation, but the truth is that both types of fiber are equally important to good digestive health! As you can see, carbohydrate-restricted diets can result in impaired GI functioning due to insufficient fiber intake. Some sources of insoluble fiber include: fruit skins, brown rice, and wheat bran. However, I don't recommend adding wheat to your diet if you are having digestive problems since wheat is often a GI trigger food.
Just like many things in life, too much of a good thing is not a good thing! It is possible that getting in too much total fiber can increase IBS symptoms, instead of making them better. I've had clients come to me with constipation who are eating 80+ grams fiber per day!
If you are eating...
- Fiber-enriched products (fiber supplements, granola bars, cereal, even yogurt)
- High-roughage veggies (asparagus, kale, broccoli, etc.)
- Fruit with skin (pears, peaches, apples, etc.)
- Sweet potatoes
- Beans and legumes (kidney beans, black beans, lentils, etc.)