The amount of fiber you consume can have a major impact on your overall health. Fiber promotes healthy digestion and has been linked to a lower risk of certain cancers, among other things. This growing awareness may explain why the “fibermaxxing” trend is gaining attention.
Why “Fibermaxxing” Has Become Popular
“Fibermaxxing” means eating at least the recommended amount of fiber for your body weight every day. This idea has gained popularity in both social media and traditional media this year. Since many people in Western dietary patterns consume significantly less fiber than recommended for health, there is a concerted effort to focus the diet more on fiber-rich foods. Although the human body cannot digest it completely, fiber fulfills important functions in the digestive system. One important aspect is its role in the intestinal microbiome, i.e. the community of microorganisms in the intestine. Many of these intestinal bacteria use fiber as a food source and produce substances that can have a positive effect on intestinal health and metabolism.
Jennifer Lee is a scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. Her research focuses on how changes in gut health and gender differences affect metabolism across the lifespan. Lee says she is not surprised that “Fibermaxxing” has become popular. In fact, she sees it as a sign that more and more people are recognizing the important difference between lifespan and healthspan. Living longer doesn’t necessarily mean spending those years in good health, so many people are looking for ways to stay healthier as they age. “There is a nine-year gap between living to a certain age in good health and living with poor health quality at the end of life,” Lee added. “Behavioral or nutritional strategies that can keep someone healthy are all the rage right now.”
Research shows that sustained low fiber intake can contribute to metabolic and cardiovascular problems, including diabetes and obesity. “If you’re not eating a lot of fiber, you may be consuming calories from other macronutrient groups, and these can be high in carbohydrates or fats, which can lead to weight gain,” Lee said. Depending on a number of factors that can influence cancer risk, a lack of fiber can then increase the risk of certain cancers such as colon, breast and prostate cancer. Overall, Lee explained that including more fiber in the daily diet usually has far-reaching health benefits.
Adhering to Daily Fiber Intake Recommendations
Meeting daily fiber intake recommendations plays an important role in a balanced diet and long-term health. The Dietary Guidelines for Americans 2020-2025, published by the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services, recommend that adults consume about 22 to 34 grams of fiber daily, depending on age and gender.
Lee also pointed out a simple guideline. For every 1,000 calories consumed, people should consume about 14 grams of fiber. Since people generally consume fewer calories as they get older, the recommended fiber intake decreases accordingly. “For a woman between the ages of 19 and 30, the average recommended daily fiber intake is 28 grams, based on a 2,000 calorie diet,” Lee said. “However, for a man in the same age group, the recommended fiber intake increases to 34 grams because he eats slightly more.”
In practice, however, it turns out that many people do not reach these guidelines. A common reason for this is the high proportion of highly processed foods in the modern diet, which often contain less fiber than unprocessed plant-based products. Nutrition experts therefore recommend specifically integrating more high-fiber foods into everyday life and gradually increasing the proportion of whole grain products, fruit, vegetables and pulses. In this way, it is usually relatively easy to achieve the recommended daily fiber intake without having to make major changes to your eating habits.
Soluble vs. Insoluble Fiber
Lee noted that dietary fiber falls into two main categories. Soluble fiber dissolves in water and slows digestion, while insoluble fiber helps move waste through the digestive tract.
Soluble fiber draws water into the intestines and forms a gel-like substance. It provides a feeling of satiety and, once it reaches the large intestine, serves as a substrate for the intestinal flora, which means that your intestinal flora can also metabolize the digested food. Thus, this type of fiber serves as a useful food source for the microbes. Soluble fiber can also help regulate blood sugar by slowing down digestion and reducing sudden spikes in glucose. They can also help lower cholesterol levels by preventing some of the cholesterol from being absorbed into the bloodstream. Foods rich in soluble fiber include many fruits and vegetables such as apples, avocados, bananas, cabbage, broccoli and cauliflower. Pulses, beans and oatmeal are also good sources. Insoluble fiber is often found in whole grains, nuts and seeds.
Insoluble fiber is particularly abundant in whole grains, bran, nuts, seeds and many vegetables. Examples include wholemeal bread, wheat bran, brown rice, carrots, cauliflower or the peel of fruit and vegetables. Eating such foods mechanically stimulates the digestive tract, which can contribute to more stable intestinal function.chemically speaking, the most important insoluble fibers include substances such as cellulose, hemicellulose and lignin, which are components of plant cell walls. As the human body cannot completely break down these structures, they enter the large intestine relatively unchanged. There they act as a kind of “filler”: they bind some water, swell slightly and increase the volume of the intestinal contents. This effect stimulates intestinal movement and facilitates elimination.
“Insoluble fiber cannot be dissolved and does not contribute to your calorie intake,” says Lee. “The body cannot derive energy from insoluble fiber, but its absorption is critical because it makes up the majority of the substrate that promotes bowel movements. Because insoluble fiber swells stool, it helps prevent constipation.” To maintain a healthy balance, Lee recommends consuming about twice as much insoluble fiber as soluble fiber each day. For example, if your daily goal is 30 grams of fiber, about 20 grams should come from insoluble fiber and 10 grams from soluble fiber.
Fiber Supplements and Possible Side Effects
For people who find it difficult to get enough fiber from their diet alone, supplements can help fill the gap. Lee pointed out that many adults do not reach the recommended fiber intake, making supplementation a viable option in some cases. However, Lee warned that increasing fiber intake too quickly can lead to digestive problems while the body gets used to it. If the body has been used to a rather low-fiber diet for a long time, the digestive system is sensitive to an abrupt increase. Often, symptoms such as flatulence, bloating or abdominal pain occur initially because the intestinal bacteria ferment larger amounts of fiber, resulting in increased gas production. For this reason, it is recommended to gradually increase the amount of fiber so that the digestive tract and the intestinal microbiome can gradually adapt.
“You could go to the extreme of eating too much: If you don’t drink enough water to balance your fluid intake and exceed the amount of soluble and insoluble fiber, you can get constipated,” Lee said. “At the other extreme, some people react differently to fiber and there is a risk of diarrhea. You should really pay attention to your body because you know how your body reacts to what you challenge it with on a daily basis.” If you want to increase your fiber intake – whether through food or supplements – you should do so gradually, drink enough and observe how your body reacts. In this way, a balance can be found in which the positive effects of fiber on digestion, satiety and metabolism can be used without unpleasant side effects occurring.