6 Warning Signs You’re Not Eating Enough Fiber

0If you’re not prioritizing high-fiber foods in your healthy diet, you might be falling short.Credit: Tatiana Maksimova / Getty ImagesMedically reviewed by Simone Harounian, MS

Why this matters: The vast majority of Americans don’t get enough fiber each day, meaning you might still be behind on your fiber goals—even if you try to eat healthy.

What you can do: Eat whole grains, legumes, nuts, and unpeeled fruits and vegetables to boost your fiber intake.

The payoff: Getting enough fiber helps you avoid constipation, blood sugar spikes, and other symptoms sometimes associated with a low-fiber diet.

Lots of people strive to eat healthy—popular diets like keto, paleo, or high-protein eating plans can offer their own set of unique health benefits. However, if your diet revolves around dairy, lean protein, and refined grains (think yogurt, chicken, and white rice), you could be missing out on fiber, a key nutrient.

Research suggests the average American adult consumes just 17 grams of fiber each day, which is far below the 25-gram or 38-gram recommendations for women and men, respectively. Here are six signs that your diet may not be delivering enough fiber—plus, how to close the gap.

Fiber adds bulk to the stool and helps it move through your intestines. That’s especially true of insoluble fiber, which is found primarily in whole grains, nuts, seeds, and the skins of fruits and vegetables.

If you’re low on fiber, you might experience constipation (infrequent, sometimes painful bowel movements). Boosting your fiber intake can help relieve those symptoms and make it easier to go to the bathroom regularly.

If your diet is built mainly around simple carbs—such as processed foods, white rice, or white pasta—you may feel satisfied in the moment, but find that your hunger returns quickly after eating. Instead, eating more complex, fiber-rich carbohydrates should help you feel fuller for longer. That’s because fiber slows down your digestion and delays the amount of time it takes for food to move out of your stomach.

Protein is another nutrient that boosts satiety, or your feelings of fullness, but if you’re still feeling hungry after eating, adding more fiber may help.

If you’re struggling to manage your cholesterol levels despite following a “healthy” diet, eating more fiber could be one way to help.

Soluble fiber—found in oats, beans, fruit, and more—forms a gel-like substance in the intestines. It limits your body’s absorption of cholesterol and fats, which may help lower levels of “bad” low-density lipoprotein (LDL) cholesterol in the bloodstream.

In addition to boosting your fiber intake, you can help lower your LDL cholesterol levels by eating a diet low in saturated fats.

If you track your blood sugar, seeing spikes after meals could be a sign that your healthy diet is low in fiber. This nutrient slows the pace at which your body absorbs carbohydrates, so fiber-rich foods help keep blood sugar levels more steady after you eat.

In contrast, the body absorbs refined carbs—such as white rice or white bread—more quickly, which can lead to blood sugar spikes. If your meals do include these kinds of carbs, be sure to pair them with fiber-rich fruits, vegetables, or legumes to help manage your blood sugar.

Not only can meals low in fiber and high in refined carbs make it harder to manage your blood sugar, but these blood sugar swings may also contribute to energy crashes a few hours after you eat. Specifically, when your blood sugar drops, you might feel hungry, irritable, or tired.

Because fiber promotes more stable blood sugar, meals that pair refined carbs with fiber-rich foods may give you steadier energy levels than ones built around refined grains alone.

Because fiber adds greater volume in your stomach and slows down digestion, it can help you feel full and manage your appetite.

If you’re following a certain diet to lose weight, without fiber, you may find it challenging to maintain a calorie deficit—even if you’re eating lots of protein. But healthy, fiber-rich foods can add more bulk to your diet without adding many calories. Depending on your dietary preferences, try options such as trail mix, popcorn, dried fruit, whole grain cereals, broccoli, or berries.

If you feel like your healthy diet isn’t giving you enough fiber, closing the gap doesn’t require a total overhaul of your eating routine. To meaningfully raise your fiber intake, you can:

Swap refined grains (such as white rice) for whole grains (such as quinoa or brown rice)

Add beans or lentils to your diet a few times per week

It’s best to increase your fiber consumption gradually, since a fast jump can sometimes cause gas and bloating. Drinking enough water may also help you avoid these gastrointestinal symptoms.

If you have digestive symptoms that persist despite changing your diet, you should check in with a doctor, since these symptoms can overlap with conditions like irritable bowel syndrome (IBS).