how much fiber should I eat daily?

what is fiber?

Fiber is a type of carbohydrate found in plant foods that can't be digested by our body. If our body can't digest it, why is it so important? Valid question. Let's start with a very brief overview of types of fiber. There are a lot of rabbit holes we could go down, but we won't. You can read more here if you want more depth on the subject. This diagram is good if visuals help you make sense of things.

insoluble fiber: does not dissolve in water

• speeds up digestion

• adds bulk to the stool

• prevents constipation
  

soluble fiber: does dissolve in water

• slows digestion

• helps you feel full

• can be classified into viscous (thick) or non-viscous (not thick)

non-viscous fibers: can be fermented by gut bacteria

• used as food (prebiotics) for good bacteria (probiotics) in the colon

• these types of bacteria help keep our gut functioning optimally

• Note: I generally avoid using "good" or "bad" when it comes to food because it doesn't have morality attached to it and binary language isn't useful. However, there are bacteria that help your body and bacteria that can make you sick or kill you, so good and bad sort of matter here.
  

isolated or synthetic fiber

This is fiber isolated from plants or synthesized and is added to food products, drinks, and supplements. You might also see these referred to as functional fibers. A few examples you might see on food or supplement labels include:

• psyllium husk

• inulin

• guar gum

• locust bean gum

You can see a longer list of FDA approved fibers here.

why do we need it?

• maintains gastrointestinal health and regular bowel movements

• food for good bacteria in the gut

• blood sugar control

• keeps you full and satisfied between meals

• lowers cholesterol levels and reduces risk of heart disease

• decreases risk for colon cancer - there's been a steady increase in adults under 50 developing colon cancer (1, 2)
  

what foods have fiber?

Most cost effective options are highlighted - these obviously can depend on where you live, what's in season, and what's on sale. You can see more ideas here.

grains + cereals

oats, rice, pasta, popcorn, bran cereal, barley, quinoa, buckwheat, farro, bread, tortillas

legumes

beans of all kinds - black, white, kidney, navy, pinto, garbanzo beans/chickpeas, lima, edamame, lentils

• These are probably the most cost effective option because dry legumes are a screamin deal. Even if you use canned, they are still pretty cheap.

fruits

pears, apples, bananas, oranges, berries, peaches, guava, kiwi, prunes, dried figs, raisins, dates

• Cost-effectiveness for produce (including veg below) can be dependent on the season

• Example: Berries are an awesome source of fiber, but I’m personally not paying $4 for a half pint of raspberries, and will wait until that shit is on sale.

vegetables

cabbage, potatoes, sweet potatoes, pumpkin, carrots, sweet corn, green peas, broccoli, squash, artichokes, avocado, Brussels sprouts, cauliflower, turnip greens

nuts + seeds

peanuts, nut butters, chia seeds, almonds, pistachios, walnuts, cashews, flaxseed, sunflower seeds, pumpkin seeds

• Nuts and seeds are usually the least cost-effective group, so scoop them up when they are on sale or opt for nut butters and chia seeds. Chia seeds aren't necessarily inexpensive, but they pack a lot of fiber in a fairly small serving.

how much fiber should I eat daily?

recommended daily intake for women

The Dietary Reference Intake (DRI) for women is around 25 grams per day. For background, this is based on about 14g of fiber per 1000 calories you eat. However, as a non-diet dietitian that generally discourages counting calories, I prefer to stick with general numbers. For most of the women I work with, ideally, I'd recommend around 30g per day.

Population-wide health data indicate that most Americans do not meet the recommended fiber intake. The average intake for adults is about 17g per day (3). With nutrition, what's most important is to recognize where you are starting. Are you only getting around 15g per day? That's okay. We can look at how you could get up to 20g and then go from there.

amount of soluble vs insoluble

The current DRI does not differentiate between soluble and insoluble; it's just total fiber. It's important to note that one is not better than the other. Many foods have both types. However, gut health can be very individualized due to gut bacteria, gastrointestinal conditions, and age, so more or less of each type might matter depending on symptoms like constipation, diarrhea, etc. I do not specialize in gut health, so I would always suggest you work closely with your physician and a gut health dietitian.

can I eat too much fiber?

There is no upper intake limit set for fiber. Based on low fiber intake of the general population, it's pretty unlikely you would eat too much. Some studies even suggest that at least 50g of fiber today is beneficial for disease prevention (4). However, the limit does possibly exist. The biggest concern is increasing your intake too quickly without also consuming adequate water to prevent constipation and serious discomfort.

how can I start adding more into my diet?

get an idea of how much you eat now

Knowing approximately how much fiber you consume in a day can be a good starting point. You can look at food labels and search for others online that don't have a label - fruits, vegetables, etc. Taking a day or two to check in with where you are can help you make a plan going forward.

HOWEVER, if you have history of an eating disorder, disordered eating patterns, or know that focus on numbers or tracking can make you spiral, I do not recommend that you do this. You can absolutely still increase your fiber intake without a focus on specific numbers or amounts.

start slowly

It's not going to feel good if you increase fiber too quickly. Trust me. Cool your jets, and add it slowly. Here are some examples of how to add to just one meal or snack a day.

• add a pear or berries to breakfast

• add a side salad or a roasted vegetable to dinner

• add trail mix or popcorn as an afternoon snack

drink more water

Because fiber interacts with water in the gut, it's incredibly important to drink more water as you add more fiber in order to prevent constipation.

try more plant-based options

Many plant proteins are also high in fiber and can be the star of the show. Or just added to the show! Note that meat and animal products don't contain fiber.

• sub lentils for half the ground turkey/beef in tacos

• sub marinated beans for protein in a salad

• sub quinoa or lentils for meat in chili or soup

look at nutrition facts labels

If this isn't something you already do, it can be helpful to see what high fiber foods you regularly eat, how much you're consuming, and compare between different options of an item. For example, comparing the fiber content between loaves of bread is an easy way to increase your fiber.

shift your mindset to adding, not cutting out other things

Addition is a more nourishing mindset compared to cutting out or restricting. This shift may also provide benefits if you are chronically undereating, intentionally or unintentionally. Below is an example of how you could add high fiber foods to what you're already doing daily.

photo by Morgan Hoover, MS, RD

bottom line

• 25-30g of fiber daily is beneficial for most women

• focus on adding more fruits, vegetables, legumes, grains + cereals, and nuts + seeds

• don't add fiber too quickly and make sure you drink plenty of water

are you looking for individualized support?

Take a look at my personalized nutrition coaching program where I'll help you shut out the noise and create a better relationship health.

disclaimer

This blog is for educational and informational purposes only. It does not constitute medical advice, diagnosis or treatment of health conditions, nutrition counseling, or a client/provider relationship.

main photo from freepik

thanks for stopping by!

xoxo, Morgan