Fiber and Healthcare Costs, Part 3: What’s Causing this Problem?
The following series of posts are from Mandy’s Capstone project for her MPH program, focused on how fiber intake could reduce the number of Americans with chronic conditions and reduce healthcare spending for all.
It’s clear that fiber intake is associated with reduced risk of chronic disease and positive health outcomes, but why do Americans consistently consume well below the daily recommended amounts of fiber? There is no one answer, but several contributing factors to the under-consumption of dietary fiber.
Misalignment of actual vs perceived intake
When surveyed, most Americans state they understand the health benefits associated with adequate fiber intake, and 67% of Americans surveyed by the International Food Information Council in 2013 believed they were meeting their daily recommended fiber targets, despite research demonstrating that only 5% of Americans hit their daily fiber target (12). There is clearly a large gap between actual fiber intake and perceived fiber intake for American adults. This may be driven, at least partially, by foods labeled as “whole grain”. Many Americans understand that whole grains are good sources of fiber, so they look at packages at the grocery store labeled as being a good source of whole grains in an effort to meet their daily fiber intake (12). However, observational studies suggest that only 15% of Americans look beyond the front label to the nutrition facts, so many people do not actually review the amount of fiber in the food they purchase, and thus overestimate the amount of fiber they consume in a day (12).
Walk down the cereal aisle at the grocery store, and you’ll notice many boxes labeled as good sources of whole grains, but with very little fiber due to the mixture of a small amount of whole grains with other ingredients. For example, Multi Grain Cheerios appear to be a good source of fiber simply based on “Multi Grain” being in the name; however, a serving (one and one third cups) has only 3g of fiber, or about 10% of your daily fiber needs (31). The front of the box of Multi Grain Cheerios also highlights “28g of whole grains”, which the average person may confuse for fiber, as many Americans think of whole grains and fiber interchangeably, even though they are not the same thing (31).
Popularity of gluten-free and low-carb diets
A gluten-free diet has become popular in recent years and has become almost synonymous with a “healthy diet”. People who follow a gluten-free diet avoid many whole grains, including wheat, barley, and rye (32). People with Celiac disease, who make up about 1% of the population, need to follow a gluten-free diet for health reasons, however nearly a third of Americans report either following a gluten-free or gluten-reduced diet, despite having no medical need to do so (32). Foods with whole grains have been found to be the largest source of fiber in the diets of American adults, at nearly 18% of all fiber, so limiting foods with whole grains by following a gluten-free diet or avoiding gluten, leads to lower overall fiber intake (8). In addition to gluten-free diets, low-carbohydrate diets have been popular in the US for years, including the ketogenic, Atkins, South Beach, paleo, and Whole30 diets, all of which limit foods that are naturally high in fiber, including whole grains, fruit, legumes, and in some cases even vegetables.
Understanding of what foods are high in fiber
A survey of American adults found that 78% believe whole grains are the best source of fiber and 85% of adults believe that foods labeled as “made from whole grains” or “whole grain ingredients” are good sources of fiber, even though the actual fiber content of foods with such labels can vary greatly (12). It has been found that over a third of items in the cereal aisle labeled as having whole grains are actually not a good source of fiber (12). Americans rely heavily on whole grains to meet their fiber needs, and as such rely on packaging labeled as whole grain to hit their fiber goal, but labels noted as whole grain do not necessarily indicate a good source of fiber. Americans also seem to understand that fruits and vegetables are good sources of fiber, but very few also rely on other sources of fiber like nuts, seeds, and legumes to meet their daily needs (8).
Food preference
The Health Eating and Lifestyle for Total Health (HEALTH) study was conducted among American adults and adolescents in order to determine barriers to healthy eating (33). The survey found that adults noted taste, other temptations, and having children who were picky eaters as major barriers to meeting recommended whole grain consumption (33). The amount of time needed to prepare whole grains and knowing how to cook whole grains were also noted as barriers to consumption (33). Barriers to vegetable consumption were similar, with respondents noting that they didn’t like the taste of vegetables, didn’t know how to prepare them, and didn’t want to argue with children in their house who don’t like vegetables (33). Perceived effects of eating too much fiber also come into play, as American adults have noted perceived gastrointestinal distress as a reason for not consuming enough fiber, despite evidence that there are no known adverse effects to consuming large amounts of fiber as long as fiber comes from a variety of sources throughout the day (8). There should not be any gastrointestinal issues if fiber is consumed from avariety of sources, which is supported by cultures who consume far more fiber than Americans (8).
Oversaturation of ultra-processed foods
The food content of American grocery stores has shifted in recent decades, with more and more items being processed and ultra-processed foods rather than minimally processed foods or foods in their whole state. Survey data of American adults indicates that as of 2017-2018, 57% of daily calories come from ultra-processed foods, most of which contain little to no fiber, as the fiber has been stripped out in the processing (34). This is an increase from the same survey conducted ten years prior in 2007 - 2008, which indicated that 55.3% of daily calories came from ultra-processed foods (34). As ultra-processed food consumption continues to increase, it becomes more and more difficult for Americans to meet daily fiber requirements. Fast-food chains and restaurants are also abundant in the US, with over 201,000 fast food restaurants as of 2023, many of which sell ultra-processed foods and foods that are high in fat and sugar, but low in fiber (35). There is an inverse relationship between ultra-processed foods and fiber intake, with fiber intake decreasing and the percentage of calories from ultra-processed foods increases (36).
Access to fiber rich foods
Access to foods that are high in fiber is also an issue for many Americans. As noted above, ultra-processed foods are readily available to many Americans, which decreases availability of whole or minimally processed foods that are high in fiber. The HEALTH study described above also found that participants noted availability of fresh fruit and ability to afford fresh fruit as major barriers to fruit consumption, another good source of fiber (33). The number one response when asked about how to eliminate barriers to fruit consumption was around improving availability and affordability (33). One of the top responses for barriers to vegetable consumption was the convenience of fast food, suggesting that fast food is more readily available than vegetables (33). There are neighborhoods and areas of the US where grocery stores may not be available and residents have to rely heavily on corner markets or convenience stores, which may not have fresh fruits and vegetables, or even have whole grains available, making it difficult for lower income Americans to meet fiber goals when ultra-processed foods and fast foods are their primary options. In areas where there is access to fresh produce and whole grains, local residents may not be able to afford to purchase these items and instead look to processed foods for cheap meals. Beans and legumes are also great sources of fiber and can be inexpensive and easy to prepare, however, many Americans don’t include them in their diets regularly and may not know they are good sources of fiber or how to prepare them.
References
(31) “Multi Grain Cheerios: Whole Grain Oat Cereal.” Cheerios, https://www.cheerios.com/products/multi-grain-cheerios.
(32) Diez-Sampedro, Ana, et al. “A Gluten-Free Diet, Not an Appropriate Choice Without a Medical Diagnosis.” Journal of Nutrition and Metabolism, vol. 2019, Hindawi Limited, July 2019, pp. 1–5. https://doi.org/10.1155/2019/2438934.
(33) Nicklas, Theresa A., et al. “Barriers and Facilitators for Consumer Adherence to the Dietary Guidelines for Americans: The HEALTH Study.” Journal of the Academy of Nutrition and Dietetics, vol. 113, no. 10, Elsevier BV, Oct. 2013, pp. 1317–31. https://doi.org/10.1016/j.jand.2013.05.004.
(34) Juul, Filippa, et al. “Ultra-processed Food Consumption Among US Adults From 2001 to 2018.” The American Journal of Clinical Nutrition, vol. 115, no. 1, Elsevier BV, Jan. 2022, pp. 211–21. https://doi.org/10.1093/ajcn/nqab305.
(35) IBISWorld - Industry Market Research, Reports, and Statistics. www.ibisworld.com/industry-statistics/number-of-businesses/fast-food-restaurants-united-states.
(36) Rauber, Fernanda, et al. “Ultra-Processed Food Consumption and Chronic Non-Communicable Diseases-Related Dietary Nutrient Profile in the UK (2008–2014).” Nutrients, vol. 10, no. 5, MDPI AG, May 2018, p. 587. https://doi.org/10.3390/nu10050587.
