Fiber 101

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by Eric Trexler, Ph.D.

The days of describing your macros as a set of three numbers are over. It’s time to give fiber the respect it deserves. To that end, this article will provide a comprehensive rundown of everything you need to know about the fourth-coolest macronutrient.

Key Points

1. Most people under-eat fiber. That’s a problem, because fiber intake is associated with lower risk for coronary heart disease, stroke, hypertension, diabetes, obesity, depression, gastrointestinal diseases, cardiovascular mortality, cancer mortality, and all-cause mortality.
2. Fiber is typically discussed in terms of two major categories: soluble and insoluble. However, knowledge of fiber-adjacent categories (such as FODMAPs, resistant starch, sugar alcohols, and gels/thickening agents) helps dieters leverage the full benefits of indigestible dietary ingredients with substantial health benefits.
3. There are defensible reasons to transiently reduce fiber intake, such as assessing fiber tolerance, elimination diets, and short-term weight cuts. However, the “default” health-promoting diet ought to contain plenty of fiber. At the very least, dieters should aim for at least 25 (female) to 38 (male) g/day, or 14+ grams per 1,000 kcal in the diet – whichever is higher.

If you ask someone what their current macros are, they’re almost certainly going to spit three numbers back at you. I can forgive them for omitting alcohol; it’s generally not a staple in your typical fitness enthusiast’s diet. I’ll give them a pass for water as well – it’s boring, it’s annoying to accurately track, it doesn’t directly impact energy balance, it can vary considerably based on day-to-day changes in environment or behavior, and our bodies are really good at making ends meet to maintain reasonably adequate hydration status. But fiber? It has taken a backseat for far too long. Fiber can tangibly impact key health metrics, energy balance, chronic disease risk, and how you feel on a given diet. As diets in industrialized economies become more and more ultraprocessed, there are growing concerns that inadequate fiber intake could be playing a major role in prevalent health issues ranging from obesity to early-onset cancer. In fact, some studies suggest that as few as 4% of Americans are regularly hitting the daily fiber intake recommendation (1). So, in this article, fiber is taking center stage under the spotlight. We’ll cover how much fiber to eat, which types of fiber to eat, key benefits of fiber consumption, and scenarios in which fiber restriction may be warranted.

Defining Fiber

Before we get too deep into the health effects of fiber, we need to establish some basics. First and foremost, fiber falls under the “carbohydrate” umbrella. But fiber is a unique type of carbohydrate, and the US Food and Drug Administration (FDA) has established criteria for what you can legally label as “fiber” on a food label. First, they clarify that fiber includes “certain naturally occurring fibers that are ‘intrinsic and intact’ in plants, and added isolated or synthetic non-digestible soluble and insoluble carbohydrates that FDA has determined have beneficial physiological effects to human health. These effects include lowering blood glucose and blood cholesterol, reducing calorie intake, and increasing the frequency of bowel movements.” They further define fiber as “non-digestible soluble and insoluble carbohydrates (with 3 or more monomeric units), and lignin that are intrinsic and intact in plants; isolated or synthetic non-digestible carbohydrates (with 3 or more monomeric units) determined by FDA to have physiological effects that are beneficial to human health.” According to the FDA website, examples of beneficial physiological effects include:

• Better glycemic control and/or insulin regulation
• Reduced fasting LDL-cholesterol
• Reduced blood pressure
• Increased frequency of bowel movements
• Increased absorption of dietary minerals
• Reduced energy intake

When they say “non-digestible,” they’re essentially talking about where absorption occurs – if it occurs at all. As shown in Figure 1, most of the macros we consume go through a pretty simple process. We eat them, they get broken down in the stomach, and they get absorbed completely (or almost completely) in the small intestine. But fiber is different – it resists digestion in the stomach and bypasses absorption in the small intestine. As a result, it reaches the large intestine (also known as the colon) intact. At that point, some types of fiber will be fermented, whereas others will pass through to the stool without ever being absorbed.

Why all the effort toward constructing an extremely specific definition of fiber, you ask? Because food companies have tried to label things as “fiber” that aren’t actually fiber, which has a big impact on how consumers perceive the food product. They think they’re seeking out a low-calorie, low-net-carb food source with a broadly underconsumed nutrient, but they’ve been misled. The most famous example in the fitness industry was a syrup labeled as “isomalto-oligosaccharides” – the primary fiber source in the original Quest Bar formulation. As it turns out, this ingredient gets substantially absorbed in the small intestine and produces glycemic responses that aren’t terribly dissimilar to those of dextrose, a form of sugar (2). In sum, its characteristics (and total metabolizable energy yield) did not warrant designation as a type of fiber.

Types of Fiber

Different types of fiber have fundamentally different characteristics, which can impact the way they’re used in food products and the way they impact our bodies. The two major types are soluble and insoluble, and they can be leveraged for distinct health benefits. While fibers are easily dichotomized based on their solubility, this classification system overstates the degree to which solubility explains the totality of a fiber source’s properties (such as viscosity or health-related effects). I’ll paint with a broad brush when comparing and contrasting soluble and insoluble fibers in this article, but please remember that these are broad generalizations subject to plenty of exceptions.

Soluble

Soluble fiber dissolves in water, which is super convenient for supplementation purposes. When soluble fiber reaches the large intestine, it is readily fermented by gut bacteria. This process produces two major products: short-chain fatty acids and gas. The short-chain fatty acids are responsible for some of the benefits we associate with fiber, whereas the gas is responsible for some of the complaints we associate with fiber (namely flatulence). If you’ve seen food products or supplements hyping up their prebiotic content, this process is what they’re referring to – providing a dietary substrate (prebiotic) that “feeds” your gut bacteria, who produce short-chain fatty acids and gas as they feast. Since we’re fermenting soluble fiber into short-chain fatty acids (which have metabolizable energy content), most soluble fibers provide roughly 1.5 to 2 kcal per gram ingested – not nothing, but certainly not the 4 kcal/gram we derive from typical carbohydrates. 

Due to extensive fermentation in the large intestine, soluble fibers typically don’t have a huge impact on stool bulk or consistency, so they generally aren’t a top choice for alleviating constipation symptoms. There are, however, exceptions. Psyllium husk power (found in Metamucil) is mostly soluble, but has some unique properties. It forms a bulky gel that holds a lot of water and is fairly resistant to fermentation, so it passes through the gastrointestinal tract largely intact and can significantly modulate stool bulk and consistency. As a result, it has high utility for the management of constipation symptoms. The characteristics of psyllium fiber are totally distinct from those of wheat dextrin (a different soluble fiber found in Benefiber), which dissolves with zero gel formation and is fermented extensively.

Insoluble

Insoluble fiber doesn’t dissolve in water and undergoes little to no fermentation. As a result, it contributes substantially to fecal bulk and is quite helpful in alleviating constipation symptoms. On the other hand, it generally doesn’t “feed” the bacteria in your large intestine very much, which means (by extension) that it doesn’t get fermented to produce beneficial short-chain fatty acids. Since it typically doesn’t get fermented to a meaningful degree, insoluble fiber essentially contributes no metabolizable calories. A general comparison of soluble versus insoluble fiber is presented in Table 1. Please note that these are generalizations, as some specific types of fiber display atypical characteristics that violate these heuristics.

Other Fibers or Fiber-Adjacent Things

While soluble and insoluble are the two major types of fiber, there are other “fiber-adjacent things” that find their way into your diet. They are worth knowing, as they can be leveraged to impact a variety of health outcomes, gastrointestinal symptoms, and even performance outcomes.

FODMAPs

The acronym “FODMAP” refers to a collection of structurally diverse dietary components: fermentable oligosaccharides, disaccharides, monosaccharides and polyols. Sugar alcohols fall under the “FODMAP” umbrella, as do some carbohydrates that fit the FDA definition of fiber. However, some FODMAPs are neither fibers nor sugar alcohols. What all FODMAPs share in common is they’re all short-chain carbohydrates that are poorly absorbed in the small intestine, osmotically active, and rapidly fermented by bacteria in the large intestine. As a result, it’s common to find FODMAPs in high-fiber foods, and they fall into the general category of carbs that are poorly absorbed in the small intestine (like all fiber) and get fermented in the large intestine (like soluble fiber). Some FODMAPs can contribute to uncomfortable gastrointestinal symptoms when ingested in high doses or by susceptible individuals; as such, low-FODMAP diets are commonly used to manage some chronic gastrointestinal conditions.

Sugar alcohols

Sugar alcohols are decidedly not fiber. However, they show up in places where fiber might be found. A great example is protein bars – somewhere along the line, manufacturers decided they wanted to load up protein bars with a bunch of novel fiber (or pseudo-fiber) ingredients and sugar alcohols. Together, they help give protein bars a sweet taste and enjoyable texture while limiting the sugar content of the bar. Sugar alcohols are particularly helpful because they provide substantial sweetness while contributing fewer calories per gram than regular sugar (most are around 2.0-2.5 kcal/gram, although they vary from almost zero to over 3 kcal/gram). But here’s the catch, which is also why we’re talking about them in a fiber article: the sugar alcohols with the lowest calorie values are typically the ones that are less absorbed in the small intestine. Whatever gets past the small intestine gets to the large intestine, where fermentation occurs (much like a soluble fiber). That’s why some sugar alcohols, particularly mannitol, sorbitol, and maltitol, are associated with significant flatulence and even osmotic diarrhea. Erythritol is a bit of an exception, because despite high absorption in the small intestine it contributes extremely low energy content (~0.2 kcal/gram). Erythritol is generally well-tolerated as a result, but this is subject to considerable variation from person to person. As a result, I implore you: if you’re in a scenario where extreme flatulence or diarrhea would be disastrous outcomes, please don’t experiment with ingestion of unfamiliar sugar alcohols or an abrupt increase in your consumption of familiar sugar alcohols. 

Resistant starch

Resistant starch is starch that escapes digestion in the small intestine and reaches the colon intact, where gut bacteria ferment it. There are five types of resistant starches (3), named “RS1” through “RS5,” which evade digestion via distinct mechanisms. RS1 is physically trapped inside intact plant cell walls or dense protein matrices, such as whole and coarsely cracked grains, seeds, and legumes. RS2 is contained inside raw starch granules whose crystalline structure blocks enzyme entry (including green banana and raw potato), but RS2 is generally lost to cooking as the granule gelatinizes. RS3 forms when gelatinized starch cools and amylose recrystallizes into tightly packed double helices (observed in chilled potatoes, rice, or pasta). RS4 is chemically modified starch, which includes starches engineered with structural modifications that do not occur in nature. RS5 consists of amylose-lipid complexes with fatty acids bound inside the helix. Once the fat is lodged inside, the starch chain is locked into a rigid coil, which makes it resistant to digestion.

Relative to other non-digestible carbohydrates, resistant starch qualifies as dietary fiber under the FDA definition. Like other types of fiber, it passes through the small intestine undigested and feeds bacteria in the large intestine. But it differs from fibers like cellulose and inulin, which resist digestion because we lack the enzymes to break their structural linkages. Resistant starch does not fall under the FODMAP umbrella, as that designation covers short-chain carbohydrates. Starch is a polysaccharide hundreds to thousands of units long, so it exerts almost no osmotic effect and ferments more slowly than FODMAPs. This slower fermentation generally makes resistant starch more tolerable, in terms of gastrointestinal symptoms, in comparison to FODMAPs. Nonetheless, resistant starch can still cause flatulence at high doses and is sometimes found within FODMAP-containing foods.

Weird gel stuff

There’s a final subcategory to address, which I’ll elegantly call “weird gel stuff.” There are all sorts of ingestible ingredients which either 1) serve as thickening agents for food products, or 2) thicken so much that they form a gel. Some of these have absolutely nothing to do with fiber, such as gelatin. Others have characteristics so similar to fiber that there have been scientific reviews to determine if they meet the FDA’s definition. In one example (xanthan gum), it was denied entry into the club. Another example is carboxymethylcellulose – we previously revieweda study using carboxymethylcellulose capsules to curb appetite by expanding to form a bulky gel within the stomach. There are also some gel-like food ingredients that are formally recognized as fiber, such as alginate. This ingredient, derived from brown seaweed, is used in a few popular sports nutrition applications. A fairly novel sodium bicarbonate product embeds little sodium bicarbonate “minitablets” within an alginate-based gel or slurry, with the intention of altering digestion and absorption rates to exploit ergogenic effects while minimizing gastrointestinal upset (4). Similarly, a relatively novel carbohydrate delivery system uses an alginate-based gel to alter carbohydrate absorption kinetics, with the goal of delivering larger doses of carbohydrate without gastrointestinal distress. It was previously common for endurance athletes to gap their carb intake at roughly 60 grams per hour, but with novel strategies (gut training, specific glucose:fructose ratios, and gel-based delivery systems), some studies are reporting high tolerance of carb intakes as high as 120 grams per hour (5).

Fiber Benefits

Fiber has a tremendous amount of research strongly supporting widespread health benefits impacting a huge range of outcomes. I’ve concisely summarized the benefits of fiber previously in MASS, so I’ll briefly restate those benefits instead of trying to reinvent the wheel. As reviewed by Anderson et al (6), high fiber intake is associated with lower risk for coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases. In a separate review paper, Barber et al (7) point out that fiber is inversely associated with all-cause mortality, along with mortality from cardiovascular disease and all cancers. There are also several plausible mechanisms by which fiber could impact outcomes related to cardiometabolic health, cancer, and gastrointestinal function. For example, fiber improves glycemic control and blood lipid profiles, and it also increases fecal mass while reducing transit time through the gastrointestinal tract. Fiber intake has even been associated with less obvious outcomes, such as better immune function, lower chronic inflammation levels, and lower risk of depression (7). These benefits haven’t changed since I reported them back in Volume 6, but they have arguably become more salient. Fiber intakes are shockingly low in modern diets containing plenty of ultraprocessed foods (1), and some papers suggest that gastrointestinal cancer rates are increasing among young adults (8) – a trend which may be attenuated by increasing fiber intake (9). The health benefits of fiber are summarized in Figure 2.

When Increasing Fiber Intake Makes sense

Based on its multifaceted health benefits, I frankly view a high-fiber diet as the default approach to a health-promoting diet. So, when does it make sense to increase your fiber intake? If you have soft stool texture or a lower-than-normal frequency of bowel movements, increasing fiber (and particularly insoluble fiber) is an intuitive idea. If you have reason to believe you’re experiencing gut dysbiosis (disruption of the balance of bacteria in your gut), increasing soluble fiber or other fermentable carbohydrates would make sense. If you routinely struggle with satiety during meals or hunger between meals, fiber is a great tool for facilitating better appetite regulation by increasing the energy density of your meals. Some research suggests that the relationship between energy density of a meal and energy intake is fairly linear (10). However, other research implies a more nuanced, threshold-based relationship in which food volume is the key satiation signal when meal energy density is below ~1.75 kcal/g, while calorie content is the key satiation signal when meal energy density is above ~1.75 kcal/g (11). This proposed relationship is displayed in Figure 3. If such a relationship holds, then adding a fiber source to reduce the energy density of a meal from 4.0 to 3.0 would be expected to have minimal impact. In contrast, a similar food swap dropping the energy density of a meal from 2.5 to 1.5 would be expected to switch the predominant satiation signal from calorie content to food volume, thus having a large impact on energy intake.

Another application of fiber-related ingredients involves “cheating the system” to reduce the number of calories consumed or absorbed from the diet. In its simplest form, this involves straightforward substitution. When a food displaces regular sugar with sugar alcohols, the total energy yield of that food decreases. But if you’re going that route, please proceed with caution. You can google a subgenre of humorous but harrowing Amazon product reviews featuring unsuspecting Haribo sugar-free gummy bear consumers who fell into this gastrointestinally catastrophic trap – as noted previously, large doses of maltitol essentially function as a highly effective laxative, especially if unaccustomed to maltitol consumption. But beyond calorie replacement, fiber and other digestion-resistant food ingredients can reduce the amount of metabolizable energy absorbed from a meal. As previously discussed in MASS, increasing the fiber and resistant starch content of a diet can reduce daily energy absorption by up to 100-150 kcal/day without substantial gastrointestinal symptoms (12). Dr. Helms crunched the numbers – a “metabolic advantage diet” that simultaneously leverages the advantages of high protein, fiber, and resistant starch intake can reduce energy balance by up to ~260 kcal/day compared to a typical “Western Diet” with the same labeled number of calories per day (Table 2).

Assessing individual-level tolerance

Before increasing fiber intake, it’s important to take stock of your current gastrointestinal comfort level. If you’re already eating plenty of fiber and you regularly feel full, bloated, and gassy, it’s possible that you’re already maxed out the upper limit of your tolerable daily fiber intake. However, it’s worth exploring alternative explanations before reaching that conclusion. As noted above, there are all sorts of dietary components (such as resistant starches, sugar alcohols, and other FODMAPs) that can contribute to flatulence and the bloated feeling that accompanies excessive gas production via fermentation in the large intestine. You may also notice that you are uniquely sensitive to certain dietary ingredients. For example, there are certain sugar alcohols I can tolerate in large doses, and others that I very much cannot. Similarly, there are certain FODMAP-containing foods that may trigger or exacerbate individualized sensitivities. In my case, apples reliably induce gastrointestinal discomfort, despite the fact that I tolerate most FODMAPs without issue. If you believe you’d benefit from higher fiber intake but are already experiencing gas and bloating, I would suggest experimenting with your intakes of fiber, resistant starches, sugar alcohols, and other FODMAPs before determining that total fiber intake is the root cause. Another important reminder is that you have the option to toggle between soluble and insoluble fiber sources. If you’re looking for more fecal bulk without gas and bloating, insoluble fiber is the focus. If you’re looking for benefits related to feeding beneficial bacteria in the large intestine, you want to shift your focus to soluble fiber (with full knowledge that more fermentation often means more gas – especially for indigestible ingredients that ferment quickly when they hit the large intestine). 

When Reducing Fiber Intake Makes sense

As noted above, more is not always better when it comes to fiber. We all have a limit on how much fiber our gut can handle, although it’s a nuanced limit. For example, your exact fiber types and sources can make a difference with regards to gastrointestinal symptoms and tolerability. In addition, I can say with confidence that your gut can acclimate to higher fiber intakes – abruptly jumping from 30 g/day to 70 g/day may cause symptoms, whereas a gradual process of increasing 5-10 g/day at a time may allow someone to gradually work up to 70+ g/day without issue. Anecdotally, I’ve found that most people feel best with a high-but-not-too-high intake, often in the ballpark of 40-70 g/day. Obviously this is a rough heuristic, not a rule, and the “right” amount of daily fiber will ultimately vary from person to person. Beyond the obvious reductions aimed at attenuating symptoms of excessive fiber intake, there are a couple other scenarios where reducing fiber intake makes sense (temporarily).

Short-term (medically supervised) elimination diet

As I explained in a previous MASS article, “elimination diets” are a valid medical intervention aimed at addressing persistent gastrointestinal symptoms. This intervention involves having a qualified professional, such as a registered dietitian, oversee a process of removing potential trigger foods until gastrointestinal symptoms subside, followed by a systematic and gradual reintroduction of potential trigger foods. In the earliest stages of an elimination diet, it’s common for fiber intake to plummet as foods containing FODMAPs and common allergens are abruptly removed. In some cases, this may end up looking a lot like a carnivore diet. But once symptoms subside, the medical professional helps the patient reintroduce foods in a systematic manner so they can carefully monitor which foods or nutrients are reliably triggering symptoms. The goal is to restrict food choices for a short period of time so the patient can subsequently build a library of suitable food options. Ultimately, the goal should be to work back toward a medically advisable daily fiber intake by utilizing tolerable food sources.

Short-term low-residue diet

If anyone has ever told you you’re “full of shit,” you may or may not be dishonest. In either case, they had a point. At any point in time, you’re carrying multiple pounds of bulk material working its way through various levels of your gastrointestinal tract. As reviewed in a previous MASS article, “low-residue diets” involve transiently reducing fiber intake to reduce the mass of this material, with the goal of temporarily reducing body weight. The most obvious application of this strategy is short-term weight cuts, completed in conjunction with carb restriction and a water cut. It generally takes food about two days to work its way through your system, although this can range from 10-96 hours (13). As such, low-residue diets are generally adopted for no more than a few days at a time. The combination of fiber restriction, carb restriction, water loading, and (within safe ranges) some degree of modest fluid restriction and sweat induction, can be used to transiently lose up to 3-5% of one’s initial body mass. Dropping fiber in a low-residue diet lasting 2-3 days should provide the bulk of the weight reduction benefits while minimizing unpleasant side effects, such as increased hunger, reduced stool frequency, and changes in stool softness. Extending this to 4-5 days could lead to slightly more weight loss, but also increase the likelihood of experiencing unpleasant effects (13). In any case, this is a short-term strategy – the general approach should be to adhere to a high-fiber diet with only transient breaks for weight reduction (as required by one’s competition schedule).

Intentional weight gain

I’ll be brief, because this section is very simple. I previously mentioned that fiber can increase satiety and support hunger management. There is, of course, a flip side of that coin. If you’re someone who struggles to eat enough calories to gain weight, a diet with tons of extra fiber certainly won’t help. When a client is struggling with lack of appetite, fiber reduction isn’t my first move – I prefer to explore other ways to incorporate palatable sources of extra calories that are relatively easy to ingest in high quantities. However, there may be cases in which someone trying to gain weight with a heavily suppressed appetite on a very high fiber diet would benefit from a targeted reduction in fiber intake.

Conclusions and Practical Applications

There is ample research suggesting that fiber confers a wide range of tremendous health benefits. As such, I think it’s fair to view a high fiber diet as the default starting point when formulating a health-promoting diet. When I say “high fiber,” I mean a diet that meets or exceeds common fiber recommendations. The adequate intake for fiber is 14 grams of fiber per every 1,000 kcal in the diet (14). When stratified by age and sex, recommended daily intakes for fiber generally range from 25-38 g/day among adults (14); these values are presented in Table 3. 

Aiming for such a diet will tend to check a lot of boxes when it comes to the Healthy Diet Indicator criteria (15) – plenty of fruits, vegetables, legumes, nuts, seeds, and whole grains, ideally at the expense of things like added sugars and processed meats. Some dieters will inevitably conclude that high fiber diets cause them gastrointestinal symptoms or distress. In such cases, I recommend troubleshooting the issue with some nuances in mind, making dietary adjustments that consider the wide range of fiber types (soluble versus insoluble), fiber-adjacent ingredients (FODMAPs, sugar alcohols, and resistant starches), and specific fiber sources that may be impacting their symptoms, rather than automatically attributing the discomfort to total fiber intake per se. When starting from scratch with a brand new client, I generally advocate for setting an initial daily fiber target no lower than the adequate intake (14 grams per 1,000 kcal) or age- and sex-dependent dietary reference intake (from Table 3) – whichever is higher. Even when someone is struggling to gain weight due to low appetite, I prefer not to go below this initial target. From there, I generally encourage clients to slowly increase their fiber intake until we find their “sweet spot” – the highest tolerable fiber intake that facilitates goal-appropriate appetite regulation without inducing gastrointestinal symptoms. 

References

1. Miketinas DC, Tucker WJ, Douglas CC, et al. Usual dietary fibre intake according to diabetes status in USA adults – NHANES 2013-2018. Br J Nutr. 2023;130(6):1056–1064. 
2. Gourineni V, Stewart ML, Icoz D, et al. Gastrointestinal Tolerance and Glycemic Response of Isomaltooligosaccharides in Healthy Adults. Nutrients. 2018;10(3):301. 
3. Baptista NT, Dessalles R, Illner A-K, et al. Harnessing the power of resistant starch: a narrative review of its health impact and processing challenges. Front Nutr. 2024;11:1369950. 
4. Gough LA, Sparks SA. The Effects of a Novel Sodium Bicarbonate Ingestion System on Repeated 4 km Cycling Time Trial Performance in Well-Trained Male Cyclists. Sports Med. 2024;54(12):3199–3210. 
5. Morton JP, Fell JM, Gonzalez JT, et al. From Metabolism to Medals: Contemporary Perspectives and Revisiting Carbohydrate Guidelines for Fueling Endurance Athletes during Exercise. The Journal of Nutrition. 2026;156(5):101442. 
6. Anderson JW, Baird P, Davis RH, et al. Health benefits of dietary fiber. Nutr Rev. 2009;67(4):188–205. 
7. Barber TM, Kabisch S, Pfeiffer AFH, et al. The Health Benefits of Dietary Fibre. Nutrients. 2020;12(10):E3209. 
8. Danpanichkul P, Suparan K, Auttapracha T, et al. Early-Onset Gastrointestinal Cancers and Metabolic Risk Factors: Global Trends From the Global Burden of Disease Study 2021. Mayo Clin Proc. 2025;100(7):1159–1171. 
9. Cui G, Jing K, Li Y, et al. Improving dietary fiber intake is associated with a declining burden of early-onset colorectal cancer: a three-decade comparative analysis in China and globally. Int J Colorectal Dis. 2026;41(1):33. 
10. Finlay AH, Boyland EJ, Jones A, et al. Passive overconsumption? Limited evidence of compensation in meal size when consuming foods high in energy density: Two randomised crossover experiments. Appetite. 2024;200:107533. 
11. Flynn AN, Hall KD, Courville AB, et al. Time to revisit the passive overconsumption hypothesis? Humans show sensitivity to calories in energy-rich meals. The American Journal of Clinical Nutrition. 2022;116(2):581–588. 
12. Corbin KD, Carnero EA, Dirks B, et al. Host-diet-gut microbiome interactions influence human energy balance: a randomized clinical trial. Nat Commun. 2023;14(1):3161. 
13. Foo WL, Harrison JD, Mhizha FT, Langan-Evans C, Morton JP, Pugh JN, Areta JL. A Short-Term Low-Fiber Diet Reduces Body Mass in Healthy Young Men: Implications for Weight-Sensitive Sports. Int J Sport Nutr Exerc Metab. 2022 Mar 21;32(4):256-264. 
14. Quagliani D, Felt-Gunderson P. Closing America’s Fiber Intake Gap: Communication Strategies From a Food and Fiber Summit. Am J Lifestyle Med. 2017;11(1):80–85. 
15. Herforth AW, Wiesmann D, Martínez-Steele E, et al. Introducing a Suite of Low-Burden Diet Quality Indicators That Reflect Healthy Diet Patterns at Population Level. Curr Dev Nutr. 2020;4(12):nzaa168.