Nutrition Insight speaks with the paper\u2019s 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.<\/p>\n
\u201cThe 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,\u201d he notes. \u201cCompared with all that noise, the evidence-based messages are not easily heard and take a while to reach public discussion.\u201d<\/p>\n
\u201cI 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 \u2018sexy\u2019 or that interesting, and most people talked about it in the context of fecal bulking.\u201d<\/p>\n
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.<\/p>\n
What makes a nutrient essential?<\/p>\n
Although there is no universally accepted definition, the researchers explain that for a nutrient to be considered \u201cessential,\u201d 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.<\/p>\n
Lead author, associate professor Andrew Reynolds.Reynolds explains: \u201c\u2018Essential nutrient\u2019 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.\u201d\u00a0<\/p>\n
\u201cNow, 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.\u201d\u00a0<\/p>\n
\u201cStill, 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 \u2018deficiency\u2019 aspect.\u201d<\/p>\n
He says that making this case is essential, as dietary fiber consumption is typically below recommended levels<\/a>, and increasing intake would benefit population health more than any other nutrient.<\/p>\n Changes from policy and industry reformulation<\/p>\n Reynolds states that recognizing fiber\u2019s 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.<\/p>\n \u201cThis recognition would lead to greater government commitment to messaging around fiber \u2014 in schools, in workplaces, and for the general public \u2014 to help raise dietary intakes to appropriate levels.\u201d<\/p>\n \u201cFor 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,\u201d he continues.\u00a0<\/p>\n Dietary guidelines: More support required\u00a0<\/p>\n Reynolds believes current evidence-based dietary guidelines are satisfactory. However, he stresses that other messaging that lacks evidence may drown out the facts.<\/p>\n \u201cThe dietary advice does not need to change much, but the environment around people needs to be supportive so that they can follow the advice,\u201d he underscores. \u201cMany 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.\u201d<\/p>\n \u201cIt 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.\u201d<\/p>\n Protein and fiber trends<\/p>\n Meanwhile,\u00a0protein has been trending<\/a> 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<\/a> and do not benefit from higher intake was largely lost. This is especially true for young, health-conscious people using social media.<\/p>\n \u201cThis 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.\u201d\u00a0<\/p>\nWhole 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\u2019s evidence-based messaging may grow interest in understanding how diet affects health, empowering them to make informed choices.<\/p>\n
Otago researchers say recognizing dietary fiber as an essential nutrient could reshape global nutrition policy and health messaging.\u201cIn 2026, I saw \u2018high fiber eating\u2019 on most of the food trends and prediction lists for the coming year \u2014 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 \u2014 e.g., Oatzempic for those who can\u2019t afford Ozempic \u2014 but the expected focus on fiber this year is truly unique.\u201d<\/p>\n