Many Americans struggle to consume enough fiber, with data from the National Institutes of Health (NIH) indicating that approximately 95 percent fall short of the recommended daily intake from sources such as berries, apples, broccoli, and lentils.
Fiber plays a vital role in promoting healthy digestion by adding bulk to stools, making them easier to pass, and prolonging satiety by slowing gastric emptying. A lack of dietary fiber, which should be between 21 and 38 grams daily depending on age and sex, can lead to short-term issues like constipation, bloating, cramping, and gas. Furthermore, inadequate fiber intake over time has been linked to chronic health problems including inflammation, diabetes, heart disease, and even colon cancer.
The Rise of ‘Fibermaxxing’
Recently, however, health professionals have raised concerns about a new trend dubbed ‘fibermaxxing.’ This practice involves consuming excessive amounts of fiber, primarily from the burgeoning market of fiber-rich snacks and sodas.
Dietitians and physicians speaking with DailyMail.com emphasize the importance of fiber for digestive health but warn that too much can cause gastrointestinal distress, including symptoms such as constipation, bloating, gas, and abdominal pain. Long-term consumption of more than 50 grams daily may also raise the risk of intestinal blockages. Some research has even suggested that inulin, a type of fiber found in high-fiber beverages like Poppi, could potentially increase the risk of liver cancer.
Expert Opinions on Fiber Consumption
Candace Pumper, a registered dietitian from The Ohio State University Wexner Medical Center, noted: “Consuming adequate fiber within established guidelines in our diet is important for optimal health and bodily function. Dietary fiber provides many functional benefits – such as adding bulk to stool, which is important for promoting regular bowel movements and preventing constipation – and physiological benefits through fermentation by the gut microbiome.”
Pumper elaborated that proper fiber intake is associated with a reduced risk of heart disease, type 2 diabetes, obesity, and colorectal cancers, stressing the necessity for most Americans to improve their fiber consumption.
As high-fiber snacks and beverages gain popularity, brands like Poppi and Olipop have emerged, offering between three to nine grams of inulin per serving. Inulin, a naturally occurring fiber found in chicory root, garlic, onions, and Jerusalem artichokes, is classified as a fructan and acts as a prebiotic, supporting the growth of beneficial gut bacteria.
Risks of Excessive Inulin Consumption
Despite the benefits, increasing evidence suggests that excessive inulin intake may contribute to adverse health outcomes. A 2018 study by Andrew Gewirtz, a biomedical science professor at Georgia State University, found that mice fed diets enriched with inulin developed jaundice, a symptom of liver failure, and exhibited signs of liver cancer over a six-month period. Furthermore, a 2024 case study highlighted a man who developed colon cancer after incorporating four grams of inulin powder into his daily diet.
Gena Hamshaw, a registered dietitian at Mount Sinai Hospital in New York City, warned that while inulin could promote a healthy intestinal microbiome, it does not provide all the benefits associated with other fiber types, particularly soluble fiber’s effect on cholesterol absorption. She stated, “It’s important to remember that there are different types of fiber, each with benefits, and the best means of reaping all of their benefits is to eat a varied diet.”
Recommendations for Responsible Fiber Intake
Experts advise against relying heavily on processed fiber sources, urging individuals to diversify their intake. Sudden increases in fiber consumption may lead to various digestive issues, with Pumper warning that excessive fiber can lead to bloating, gas, and discomfort, while potentially impairing nutrient absorption.
Hamshaw added that while it is rare, extremely high fiber intake could lead to intestinal blockages, especially in individuals with prior digestive conditions or surgeries. She cautioned that consuming upwards of 50 grams of fiber could complicate health outcomes, with Dr. Omer Awan from the University of Maryland suggesting that complications could arise at levels closer to 70 grams.
Moreover, Hamshaw emphasized that whole plant foods rich in fiber, such as fruits, vegetables, seeds, grains, and nuts, are typically also nutrient-dense and provide essential vitamins and minerals. While fiber-fortified snacks and sodas can complement a healthy diet, prioritizing naturally occurring fiber in nutrient-rich foods will yield the best health outcomes.
