Kerry: Optimizing fibermaxxing for gut health with fiber diversity and smart reformulation

Social media is bringing gut health to the forefront, with the “fibermaxxing” trend shaping the younger generation’s approach to food. Kerry notes that while protein’s claim to the limelight has prevented other nutrients from shining, the diet has gone viral online, where trends emerge quickly. 

Nutrition Insight speaks with a senior nutrition scientist at Kerry, who discusses the risks of fiber overconsumption, the importance of fiber diversity, and reformulation solutions. 

Fibermaxxing trends have much potential to close the fiber gap — where the company’s research shows many people, especially in the West, are not meeting recommended levels. However, there may also be a risk of overconsuming this nutrient amid the hype.

Kerry points out the online trends encourage healthy fiber intake, but some “gamify” it to “max out.” Here, the health messaging takes a turn as “overmaxxing” the nutrient interferes with micronutrient absorption.

Registered nutritionist and chartered scientist Dr. Aisling Aherne says: “Scientific evidence strongly associates optimal fiber intake with reduced risks of cardiovascular disease and several cancers, especially colorectal cancer, as well as improved metabolic and gut health. Dietary fiber intake of around 25–40 g/day in adults is well-tolerated.”

“From a scientific perspective, side effects can begin when fiber intake exceeds the gut’s physiological tolerance (up to 50 g/day), especially when intakes are highly concentrated and/or rapidly increased.”

She adds that when fiber intake is low, gradually increasing consumption is better to avoid experiencing gut issues such as bloating, cramping, constipation, and diarrhea. Additionally, people should be careful when taking fiber supplements, as they could easily consume too much.

“Conversations about fiber intakes shouldn’t distract from the fact that achieving greater than 40 g of dietary fiber per day is challenging, and most people are not getting enough dietary fiber in the first place, which needs to be addressed.”

Fiber diversity

Discussions should not just focus on fiber quantity, as fiber diversity is also important for achieving different health benefits, says Aherne. 

Dr. Aisling Aherne, senior Nutrition Scientist at Kerry.Kerry notes that some fiber “maxxers” take supplements to meet recommended fiber levels. However, supplements alone do not bring the benefits compared to increasing fiber diversity.

“The term ‘dietary fiber’ refers to a large group of complex structures that deliver a wide range of functions, such as for heart, metabolic, gut, and/or potentially mental health,” explains Aherne.

“For instance, fibers from wheat bran promote good bowel function, and oat beta-glucan fibers reduce LDL cholesterol, often called “bad” cholesterol, whereas certain fibers also act as a food source for the gut microbiota, which produce metabolites that can be beneficial to health.”

Soluble fiber helps slow digestion, control blood sugar, and lower cholesterol, and is found in foods like oats, nuts, beans, and apples. 

Meanwhile, insoluble fiber remains unchanged when digested, preventing constipation, and is found in whole-wheat flour, nuts, seeds, and vegetable skins. This fiber binds water in the large intestine, meaning more fluid is required for the fiber to work properly.

Kerry suggests that counting fiber initially can be beneficial, but in the long term, forming habits is better. The company adds that social media posts should go beyond sharing messages of regular bowel movements and instead inspire tasty recipes to help dispel the myth that fiber is bland and boring.

Previous research on TikTok’s impact on younger consumers’ diets and food habits found that visually appealing, dynamic food content has a stronger influence on young users’ diets.

Recently, experts urged recognition of fiber as an essential nutrient for reducing chronic disease risk.

Reformulation considerations

Many high-fiber products rely on fiber to reduce sugar or calories. Aherne explains that, for formulation, manufacturers should factor in regulations concerning fiber alongside allergen information.

Diverse fibers — from oats to beans — unlock gut, heart, and metabolic benefits beyond simple quantity goals.“Additionally, when adding fiber to foods, manufacturers should consider the overall nutritional profile, as consumers increasingly question products that offer a health claim but contain high levels of sugars, saturated fat, and/or salt.” 

“Therefore, manufacturers aiming to make fiber claims should assess whether broader reformulation of sugars, saturated fat, salt, or portion size adjustment is needed to maintain consumer credibility,” she explains.

Kerry suggests that fiber can be used to replace sugar or fat or to improve food structure in gluten-free products at 2 kcal/g, depending on local regulations. Fiber can also reduce energy value when substituting carbohydrates (4 kcal/g) or fat (9 kcal/g).

According to this year’s nutrition innovation trends, protein and fiber are set to dominate, driven by consumer demand for multifunctional, convenient products that support gut health and satiety. Nutrition Insight previously spoke with FrieslandCampina Ingredients and Lonza Capsugel about opportunities for fiber formulation.

Meanwhile, a recent study linked processed foods that lacked fiber with greater cognitive decline in aged brains.

Additionally, Aherne says that manufacturers should aim to balance their formulations’ efficacy with consumer experience targets. She notes that if they add a small and well-tolerated amount of fiber, they can achieve a “source of fiber” claim. However, if they add enough to qualify for a “high in fiber” claim, it may increase the risk of digestive discomfort.

“In many cases, combining multiple fiber types can improve both tolerance and functional performance. Clear communication of recommended serving sizes also supports a positive consumer experience,” she concludes.