Trends come and go. Protein had its moment in the spotlight for a while and now fiber is getting louder, and I love it. Fiber deserves the attention. It’s one of the most important things for overall health, and it’s been overlooked for way too long.
So what actually is fiber? Fiber is a type of carbohydrate found in plant foods that your body can’t digest or absorb. Which raises the obvious question: if we can’t digest it, what’s the point?
Fiber doesn’t get broken down for energy. Instead it passes through your stomach, small intestine, and colon largely intact. That’s exactly what makes it so powerful. It gets things moving. Fiber is what keeps you regular, helps prevent constipation, and can even help with diarrhea.
Fiber also does wonders for cholesterol. When someone gets diagnosed with high cholesterol, the instinct is usually to immediately cut out eggs and red meat. That’s not really how cholesterol works. What actually helps is fiber. It binds to cholesterol in the digestive system and helps lower cholesterol levels in your blood.
Fiber is also key for blood sugar regulation, right alongside fat and protein. It slows the absorption of sugar, which helps prevent spikes. You can read more about blood sugar in my previous post The Truth About Sugar.
Fiber is also a prebiotic, meaning it feeds the good bacteria living in your gut. A healthy gut plays a role in way more than digestion, including immune function and even mood, since a huge amount of serotonin is actually produced in the gut. Keeping your fiber up is one of the simplest ways to support that whole system.
Just like protein and fat, fiber helps keep you full and satisfied. It adds bulk to meals so you stay fuller longer, which can support weight management too. Fiber is technically a carb, but it gives you all of these benefits without ever actually being digested.
There are two types of fiber, and they each do something a little different.
Soluble fiber dissolves in water to form a gel. This slows digestion, helps lower blood sugar, and reduces cholesterol levels. You’ll find it in oats, barley, legumes, the flesh of apples, pears, citrus fruits, bananas, blueberries, carrots, brussels sprouts, sweet potatoes, and chia or flax seeds.
Insoluble fiber doesn’t dissolve in water. Instead it adds bulk to your stool and helps food pass through your digestive tract more quickly, which helps prevent constipation. You’ll find it in whole grains, cauliflower, green beans, potatoes, dark leafy greens like kale, cabbage, fruit skins, berries with edible seeds, nuts, seeds, and legumes.
It can get confusing since a lot of foods overlap between the two. Rule of thumb: there are five fiber categories, which are beans and lentils, fruits, vegetables, whole grains, and nuts and seeds. If you’re getting a variety across those five throughout the day, you’re likely covering both types.
So how much fiber do you actually need? The recommended daily intake is 25g for women and 38g for men. Most people fall short of this daily.
The important part is that more isn’t always better right away. If you jump straight to the full recommended amount when your body isn’t used to it, you will feel it. Cramps, painful bloating, gas, diarrhea, constipation, even dehydration since fiber pulls in water, and uncomfortable fullness are all possible. Increase your fiber slowly over time instead of all at once. As you increase it, increase your water right alongside it. Fiber needs water to actually do its job. Without enough water, more fiber can make constipation worse instead of better.
Whole food sources of fiber are generally the better choice over fiber supplements or powders, since you get the fiber alongside all the other nutrients and benefits whole foods provide. That said, supplements can be a helpful bridge if you’re genuinely struggling to hit your numbers through food alone.
Fiber matters even more given the rise in colorectal cancer we’re seeing. A high fiber diet can help lower that risk. Aim to include at least a couple of fiber sources at each meal, mixing from those five categories. Nuts and seeds, lentils and beans, fruits, vegetables, whole grains. Mix and match and have fun with it.
If you want to go deeper, my Nutrition Toolkit covers protein, fat, carbs, fiber, and water, plus the balanced plate method, so you can see how it all fits together on your plate. You can find it on my website.
— Ivy ♡
Disclaimer: This blog is for general informational and educational purposes only and does not constitute medical advice, diagnosis, treatment, or personalized nutrition counseling. It is not a substitute for care from a qualified healthcare professional. If you are struggling with disordered eating, support is available through the Alliance for Eating Disorders at 1-866-662-1235.