Experts urge fiber’s recognition as an essential nutrient for reducing chronic disease risk

Aotearoa New Zealand researchers at the University of Otago are advocating for the international recognition of dietary fiber as an essential nutrient. If successful, this would mark the first addition in 50 years.

Currently, carbohydrates, proteins, fats, vitamins, minerals, and water are typically upheld as essential nutrients. However, the researchers argue that increasing fiber intake can yield significant health benefits, such as reducing diabetes, heart disease, and colorectal cancer risks, which are all on the rise.

They add that in New Zealand, many citizens fall short of the WHO fiber recommendations, averaging 20 g of fiber/day against 25 g/day. Simple diet changes, such as increasing whole grains and legumes, can help people reach the recommended level.

The commentary in Nature Food argues that recognizing fiber’s essential role can impact guidelines and health messaging, potentially reducing non-communicable diseases.

Nutrition Insight speaks with the paper’s lead author, associate professor Andrew Reynolds, about how fiber is rising in tandem with popular high-protein diets. We also discuss how this nutrient could raise questions about current dietary guidelines, the benefits to the gut microbiome, and barriers to increasing fiber uptake.

“The dominant source of nutrition messaging in our society is from people who make money when we consume their content: lifestyle books, cookbooks, and ads on social media,” he notes. “Compared with all that noise, the evidence-based messages are not easily heard and take a while to reach public discussion.”

“I would say that the current situation, where the benefits of dietary fiber are being talked about in scientific and social commentary, is quite rare! I would also say that dietary fiber, for a long time, was not considered ‘sexy’ or that interesting, and most people talked about it in the context of fecal bulking.”

Fiber has only gained attention over the last seven years, proving its benefits for a healthy microbiome, which is causing its label as being boring to shift, adds Reynolds.

What makes a nutrient essential?

Although there is no universally accepted definition, the researchers explain that for a nutrient to be considered “essential,” it must be beneficial to health, not be produced by the body, and its absence would result in a deficiency. The gut microbiome, for instance, almost exclusively relies on dietary fiber.

Lead author, associate professor Andrew Reynolds.Reynolds explains: “‘Essential nutrient’ is an old term that gained great prominence when scientists were still understanding the parts of food required for humans to survive. For example, when sailors were offshore for many months, they got scurvy, which is a deficiency of vitamin C. Giving them vitamin C resolved the scurvy; it was quite a simple process of cause and effect.” 

“Now, however, we understand nutrition at a much more complex level and have moved on from deficiency states to more often consider causal associations and interaction effects between dietary components over the lifespan.” 

“Still, essential nutrients are monitored and surveilled more seriously than nutrients not considered essential, so in order for us to build a case of essentiality for dietary fiber, we had to consider and address the ‘deficiency’ aspect.”

He says that making this case is essential, as dietary fiber consumption is typically below recommended levels, and increasing intake would benefit population health more than any other nutrient.

Changes from policy and industry reformulation

Reynolds states that recognizing fiber’s essentiality will bring several changes. For instance, at the policy level, there will be greater emphasis on monitoring essential nutrients, meaning more focus on fiber as a shortfall nutrient.

“This recognition would lead to greater government commitment to messaging around fiber — in schools, in workplaces, and for the general public — to help raise dietary intakes to appropriate levels.”

“For industry, recognizing essentiality is a motivator for reformulation of current foods to have more fiber in them. This might have benefits for the industry in terms of how they label and market their products and how their products might compare with competitor products,” he continues. 

Whole grains, legumes, fruits, and vegetables are key sources of dietary fiber linked to improved gut health and reduced chronic disease risk.For individual consumers, he notes fiber’s evidence-based messaging may grow interest in understanding how diet affects health, empowering them to make informed choices.

Dietary guidelines: More support required 

Reynolds believes current evidence-based dietary guidelines are satisfactory. However, he stresses that other messaging that lacks evidence may drown out the facts.

“The dietary advice does not need to change much, but the environment around people needs to be supportive so that they can follow the advice,” he underscores. “Many foods are processed so that they are easy to store, prepare, and eat and are made to a formula we find incredibly delicious and rewarding to eat.”

“It is hard for many people to move away from foods processed that way, especially when they are time poor and do not have the means to prepare healthy and delicious foods. Lots of work needs to be done to change the environment around people to help them meet the evidence-based dietary advice.”

Protein and fiber trends

Meanwhile, protein has been trending consistently, especially in the US. Reynolds agrees that the macronutrient has been huge in 2025. However, he cautions that the evidence-based messaging that most people already consume sufficient protein and do not benefit from higher intake was largely lost. This is especially true for young, health-conscious people using social media.

Otago researchers say recognizing dietary fiber as an essential nutrient could reshape global nutrition policy and health messaging.“In 2026, I saw ‘high fiber eating’ on most of the food trends and prediction lists for the coming year — I have never once seen fiber on one of these lists, so that is quite a change. There were smaller trends in 2025 around fiber — e.g., Oatzempic for those who can’t afford Ozempic — but the expected focus on fiber this year is truly unique.”

“This is in stark contrast to the focus of the newly released Dietary Guidelines for the US. I would say the evidence behind these guidelines is good, but what the evidence showed was not taken through to the dietary guidelines like it should have been.” 

“The messaging in the US guidelines is also quite inconsistent — especially around how whole grains are promoted (or not), processed meat, alcohol intakes, and saturated fat intakes,” he points out. 

Consumers will likely be more confused about what to eat as a result of the inconsistency, says Reynolds. The lack of attention to food sustainability is another issue. 

“We are all exposed to dietary messages every day. Most of them are not evidence-based. However, this constant exposure confuses people and most likely distracts from the changes that would benefit health the most.”

He praises the new Dutch Dietary Guidelines, released in December 2025, which are evidence-based and reflect current science. It recommends a fiber intake of 25 g/day for women and 30 g/day for men. To achieve this goal, the guidelines promote consuming more whole grains, legumes, vegetables, and whole fruit.