As far as macronutrients go, fiber is one of the most important. Eating enough of it can help maintain your bowel health, lower cholesterol, and control blood sugar levels. Yet, while most people are concerned with not getting enough fiber, consuming too much can also be a problem. Overdoing it can lead to uncomfortable side effects and potential health complications. Read on as we explain the signs that you’re getting too much fiber.
When you ingest too much fiber, gastrointestinal distress, arguably the most noticeable sign that something in your diet has gone amiss, is bound to happen. “[A] potential risk involved with eating large amounts of fiber is getting constipated, which can happen if one does not drink adequate water,” explains Samantha Hass, registered dietitian at F-Factor, a private practice in New York City. Most of the fiber you eat combines with water when in the GI tract. This ends up forming soft, healthy bulk. When you consume too much fiber and not enough water, the imbalance can lead to hard stools that are tough to pass (and all of the issues that come with that).
Moreover, excessive fiber may end up interfering with water retention, causing a fluid imbalance. For these reasons, it’s paramount that you drink enough water and eat the right amount of fiber (more on that later). This means upping your water intake if you end up raising your fiber intake. Messing with this balance can result in bloating, gas, constipation, and cramping.
Pain may also take place in your lower abdomen if you’ve had too much fiber and not enough fluids. If this pain persists, you may have a blockage, or fecal impaction. Fecal impaction is when a large, hard stool forms under these conditions and gets stuck in your digestive tract. Overeating fiber isn’t the only cause of this type of blockage (a twisted bowel, inflammation, and damaged blood vessels are other causes). However, it is the most common.
The level of symptoms you’re experiencing should indicate what you can do to help improve the pain, cramping, and fullness. Mild symptoms (bloating and occasional abdominal pain) can be improved by a low fiber diet. Moderate symptoms (abdominal pain, cramps, and bloating that doesn’t go away) can be improved by a minimal fiber diet. Severe symptoms (severe abdominal pain, heartburn, significant bloating, and nausea) can be improved by avoiding any fiber and contacting your doctor. We also suggest placing a heating pad on your abdomen during bouts of intense pain. If adjusting your diet at home doesn’t seem to help, see your doctor as soon as you can.
A less common, but still possible effect of eating too much fiber is mineral deficiencies. Because fiber can bind to minerals such as magnesium, iron, calcium, and zinc, ingesting too much fiber can limit the absorption of these micronutrients. Large amounts, especially when taken as a supplement, can cause this and, over time, lead to a mineral deficiency. This is more likely to happen during periods when the vitamins and minerals were most needed. These include lactation, pregnancy, and adolescence.
Luckily, for this to happen you’d need to ingest an incredibly unlikely amount of fiber in one or more days. “While some warn of a potential vitamin and mineral malabsorption when numbers as high as 80 grams of fiber per day are consumed, concern for this is [almost] unnecessary, as it is rather rare [that] anyone eats anywhere near that amount,” Hass explains. “The average American is lucky if they get above 15 grams per day.” However, if you think you could be experiencing mineral deficiencies, consider lowering your fiber intake, taking a multivitamin or mineral supplement, and contacting your doctor.
Loss of Appetite
This sign, which may seem very obvious, is often misattributed or disregarded. As expected, when you eat too much fiber you’re likely to feel very full. When done often, it’s possible you’ll develop a decrease in appetite or early satiety during meals. This is because fiber often acts as bulk or “roughage” in the stomach. The more you eat, the fuller you’ll feel.
While this is good to an extent, especially if you’re attempting to lose weight, it can become a problem when you consume too much fiber. Due to that fullness, you may become unable to consume enough energy (food) throughout your day, leaving you tired and uncomfortable or bloated. In the long run, this lack of proper food consumption could negatively affect muscle gain. If you’re feeling unusually full towards the beginning, or after, meals, check the amount of fiber in your diet. It may be having a longer-term effect than you realize.
Should you be concerned?
While, yes, it is possible to generally consume too much fiber (and reap the repercussions of doing so), you’re very unlikely to. Plus, even if you do, the impact on your body isn’t considered dangerous. This makes the definition of “too much” more of a largely held opinion rather than definitive fact. In fact, due to insufficient evidence, no recommended daily allowance (RDA) on fiber has been set.
“There is no need for concern over eating too much fiber. Because fiber is ingestible, there’s no such thing as a toxicity level,” says Hass. A substance’s toxicity level is the degree to which the substance can harm humans or animals. This means that, even when eaten in large amounts, fiber doesn’t cause acute (short-term), subchronic (lasting more than a year), or chronic (for an extended period) toxicity. In that vein, you can’t eat too much fiber—or rather, enough to be considered toxic.
This aside, it’s important to aim for the recommended amounts of fiber in order to avoid those uncomfortable side effects. The Office of Disease Prevention and Health Promotion recommends 25-30 grams of dietary fiber per day for adult males and females. That being said, it’s okay if you find yourself eating a bit more than that (Hass mentions that her clients regularly eat around 40-55 grams per day). It’s all about striking the right balance and avoiding going overboard—especially when it comes to supplements.
Best Way to Ingest Fiber
When including fiber in your diet, the best way to do so is through food. Naturally fibrous foods, such as lentils, beans, artichokes, broccoli, Brussels sprouts, berries, and apples are your best bet, but foods fortified with fiber can largely help you reach your recommended amount. Just keep track of how you’re feeling during and after meals, and adjust your intake accordingly, if needed.