Chalk lettering spelling FIBER on a board ringed by vegetables, fruit, legumes and grains

Fiber & Blood Sugar: Why It Matters and Easy Ways to Get More Each Day

Key Takeaways

If you want one dietary change that could improve your blood sugar control, start with fiber. It is not glamorous and it does not come in a trendy package. But the research on fiber and glucose management is among the most consistent in nutrition science.

Still, most people fall well short of their fiber goals. The Institute of Medicine sets 25 g (0.9 oz) a day for women and 38 g (1.3 oz) for men, and typical diets land far below that. These are US figures. In the UK, government advice is 30 g (1.1 oz) a day for adults.[3][4]

This article explains how fiber affects blood sugar, how soluble and insoluble fiber differ, which high-fiber foods have the strongest evidence for glucose management, and how to eat more without overhauling your diet. It pairs well with our guide to foods that keep blood sugar stable.

This guide is general education. If you use insulin or other glucose medicines, follow the plan your diabetes team gave you.

How does fiber affect blood sugar?

To understand why fiber matters for blood sugar, it helps to understand what happens when you eat carbohydrates without much fiber. Simple and refined carbohydrates are broken down quickly in the digestive tract. The resulting glucose floods into the bloodstream rapidly, causing a sharp spike in blood sugar. Your pancreas responds by releasing a large burst of insulin to shuttle that glucose into cells.

Fiber changes this process. Soluble fiber dissolves in water and forms a thick, viscous gel in your digestive tract. This gel physically slows the rate at which food moves from your stomach into your small intestine, a process called delayed gastric emptying.[1] It also creates a barrier along the intestinal wall that slows the absorption of glucose into the bloodstream.

The result is that fiber tends to blunt the rise in blood sugar after a meal, though how much varies from person to person and meal to meal. A trial published in the New England Journal of Medicine found that a high-fiber diet of 50 g (1.8 oz) per day improved glycemic control in patients with type 2 diabetes, reducing daily glucose levels by about 10% compared with the standard recommended diet.[10]

Fiber also slows the enzymatic breakdown of starches. By physically encasing carbohydrate molecules within the gel matrix, soluble fiber reduces the accessibility of digestive enzymes like alpha-amylase, meaning that carbohydrates take longer to be converted into glucose in the first place.[8]

Soluble vs. insoluble fiber: what is the difference?

Not all fiber works the same way for blood sugar. Knowing the two main types helps you choose better foods.

Soluble fiber

Soluble fiber dissolves in water to form a gel-like substance. This is the type most directly responsible for slowing glucose absorption and improving post-meal blood sugar levels. It also helps reduce LDL cholesterol by binding to bile acids in the gut.[2]

Good sources of soluble fiber include:

  • Oats and oat bran (beta-glucan is the key soluble fiber)
  • Beans, lentils, and chickpeas
  • Psyllium husk
  • Barley
  • Apples, citrus fruits, and berries (pectin)
  • Flaxseeds and chia seeds
  • Sweet potatoes and carrots

Insoluble fiber

Insoluble fiber does not dissolve in water. Instead, it adds bulk to stool and helps food pass through the digestive system more efficiently. While it has less direct impact on glucose absorption, insoluble fiber plays an important supporting role. It promotes satiety (the feeling of fullness), which can help you eat less at meals and reduce overall carbohydrate intake.[11]

Good sources of insoluble fiber include:

  • Whole wheat and wheat bran
  • Nuts and seeds
  • Cauliflower, green beans, and broccoli
  • Dark leafy greens
  • Potato skins

Most whole plant foods contain a mix of both types. For blood sugar, foods rich in soluble fiber give the most direct benefit. A diet with both types supports overall metabolic health.

Soluble vs. insoluble fiber at a glance

Fiber type. What it does in the gut. Main blood sugar effect. Whole-food sources.
Soluble (viscous, gel-forming).[1][2] Dissolves in water to form a thick gel. Slows stomach emptying and enzyme breakdown of starch. Fermented by gut bacteria into short-chain fatty acids.[1][8][12] Directly blunts post-meal glucose spikes and reduces fasting glucose and HbA1c in clinical trials.[10][5][13] Oats and barley (beta-glucan), beans, lentils, chickpeas, psyllium husk, apples, berries, chia and flaxseeds.[1][6][13]
Insoluble.[11] Does not dissolve in water. Adds bulk to stool and supports regular digestion.[11] Less direct effect on post-meal glucose absorption, but supports fullness (satiety) and whole-diet quality.[11] Whole wheat bran, nuts, seeds, cauliflower, green beans, broccoli, leafy greens, potato skins.[4][11]

When reading food labels, look at "total dietary fiber" rather than trying to distinguish between soluble and insoluble. A food with 5 g (0.18 oz) or more of fiber per serving is considered "high fiber." If the label also lists soluble fiber separately, aim for foods where soluble fiber makes up at least 1 to 2 g (0.04 to 0.07 oz) of the total. Our guide to reading food labels explains how to spot hidden sugars alongside fiber.[4]

What does the research say about fiber and blood sugar?

The evidence is extensive and consistent across populations and study designs.

Large-scale observational evidence

A large series of meta-analyses published in The Lancet in 2019 analyzed data from 185 prospective studies and 58 clinical trials involving over 4,600 participants. The researchers found that people consuming the highest levels of dietary fiber had a 15 to 30% smaller risk of all-cause mortality, cardiovascular death, type 2 diabetes, and colorectal cancer compared to those consuming the least fiber.[14] Separate meta-analyses link higher fiber intake to smaller cardiovascular disease risk[15] and reduced mortality from cardiovascular disease and cancer.[7]

A separate meta-analysis focusing specifically on fiber and type 2 diabetes risk, which pooled 17 prospective cohort studies, found that people eating 30 to 35 g (1.1 to 1.2 oz) of fiber a day had a 24 to 34% smaller risk of type 2 diabetes. Each extra 2 g (0.07 oz) of cereal fiber a day was linked to a 6% smaller risk.[16] Higher fiber intake is also linked to improved insulin sensitivity, a key mechanism in preventing type 2 diabetes.[17]

Clinical trial evidence

In a randomized controlled trial published in the New England Journal of Medicine, researchers assigned 13 patients with type 2 diabetes to either a high-fiber diet of 50 g (1.8 oz) a day or a moderate-fiber diet of 24 g (0.85 oz) a day, consistent with ADA recommendations at the time. After 6 weeks, the high-fiber group showed significantly reduced daily glucose levels, reduced insulin levels, and reduced total cholesterol compared to the moderate-fiber group.[10]

A meta-analysis of fiber trials in type 2 diabetes reached the same conclusion. Adding fiber reduced both fasting blood glucose and HbA1c compared with placebo.[18]

Chandalia and colleagues concluded in the New England Journal of Medicine that eating soluble-rich dietary fiber above the standard level recommended by the ADA improved glycemic management, reduced hyperinsulinemia and reduced plasma lipid concentrations in people with type 2 diabetes.[10]

Does psyllium husk help with blood sugar?

Yes. Among fiber supplements, psyllium husk is the most studied for blood sugar management. Psyllium is a soluble fiber derived from the husks of seeds of the plant Plantago ovata. When mixed with water, it forms a thick, viscous gel that is particularly effective at slowing glucose absorption.

A meta-analysis of 35 randomized controlled trials found that psyllium supplementation significantly reduced fasting blood glucose, HbA1c, and HOMA-IR (a measure of insulin resistance) in patients with type 2 diabetes.[5] The meta-analysis was written by authors employed by Procter & Gamble, the maker of Metamucil, and the company funded it.[5] If you are not sure what that number measures, our guide to the HbA1c test explains it.

A separate study published in the European Journal of Clinical Nutrition found that 14 g (0.5 oz) of psyllium a day for six weeks reduced glucose absorption after a test breakfast by about 12% in 20 patients with type 2 diabetes.[19]

The most commonly studied dosing protocol is 5 to 10 g (0.18 to 0.35 oz) of psyllium taken with water immediately before meals. Starting with a smaller dose and increasing gradually helps minimize digestive discomfort. Adequate water intake is essential because psyllium absorbs many times its weight in water.

Pro Tip

If you are new to psyllium, start with 2.5 g (0.09 oz), about half a tablespoon, before one meal per day. After a week, increase to 5 g (0.18 oz) before your largest meal. Over the following weeks, you can gradually work up to 5 g (0.18 oz) before two or three meals if tolerated. Mix each dose into a full glass (at least 8 fl oz, or 240 mL) of water and drink it right away. Psyllium taken without enough fluid can swell and cause choking. Take other medicines at least 2 hours before or after psyllium, because it can affect how they are absorbed. Check with your doctor or pharmacist before you start, especially if you take diabetes medication, since your blood sugar may drop.[5]

Are beans and lentils good for blood sugar?

Yes. If one food group stands above all others for fiber-based blood sugar management, it is beans and legumes. They combine high fiber content with substantial plant-based protein, resistant starch, and a low glycemic index, making them one of the most effective foods for glucose control.

A meta-analysis of 41 randomized controlled trials published in Diabetologia found that dietary pulse (bean, lentil, chickpea) consumption significantly improved markers of long-term glycemic control, including fasting blood glucose and fasting insulin levels.[6]

A randomized trial in the Archives of Internal Medicine followed 121 adults with type 2 diabetes for three months. One group ate a low glycemic index diet that asked them to add at least 1 cup of legumes a day. The other group added insoluble fiber from whole wheat products. HbA1c fell by 0.5 percentage points on the legume diet and by 0.3 points on the wheat fiber diet, so the legume diet came out 0.2 points ahead.[20] The legumes were part of a wider low glycemic index diet, so the result reflects the whole diet and not beans alone.

Fiber content of common legumes (per 1 cup cooked):

  • Navy beans: 19 g (0.67 oz)
  • Black beans: 15 g (0.53 oz)
  • Lentils: 16 g (0.56 oz)
  • Chickpeas: 12 g (0.42 oz)
  • Kidney beans: 13 g (0.46 oz)
  • Split peas: 16 g (0.56 oz)

Beyond their fiber content, legumes also contain resistant starch, a type of carbohydrate that resists digestion in the small intestine. Resistant starch acts similarly to fiber, reaching the colon intact where it feeds beneficial gut bacteria and further supports glucose regulation.[21] In humans, resistant starch intake reshapes the gut microbiota and has been shown to facilitate weight loss.[22]

Are whole grains good for blood sugar?

Whole grains help, but the form matters. They are an important source of dietary fiber, but not all grains are equal. The key distinction is between intact whole grains (where the grain kernel remains largely whole) and finely milled whole grain flour (where the grain has been ground into fine particles).

Intact whole grains like steel-cut oats, barley, quinoa, and bulgur retain their physical structure, which means they must be broken down more slowly during digestion. This structural integrity is a major reason why they produce a more gradual glucose response compared to refined grains.

An analysis of three large prospective cohorts published in The BMJ found that higher whole grain consumption was associated with a significantly smaller risk of type 2 diabetes.[23]

The beta-glucan in oats and barley is worth a closer look. This soluble fiber has been studied extensively. A meta-analysis found that consuming at least 4 g (0.14 oz) of beta-glucan from oats or barley per meal can significantly reduce post-meal glucose and insulin responses.[13] That is roughly the amount in one cup of cooked oatmeal.

Choosing the right grains

Strongest choices for blood sugar (intact or minimally processed):

  • Steel-cut or rolled oats (not instant)
  • Barley (pearled or hulled)
  • Quinoa
  • Bulgur wheat
  • Brown rice (a moderate choice that is smaller in glycemic impact than white rice but still significant)

Less ideal choices (finely milled, even if labeled "whole grain"):

  • Whole wheat bread (fine flour still digests quickly)
  • Whole wheat pasta (better than white but still relatively fast-digesting)
  • Instant oatmeal packets (often contain added sugars and highly processed oats)

How does fiber affect the gut microbiome and blood sugar?

Research increasingly shows that fiber helps blood sugar beyond its mechanical effects in the digestive tract. Fiber is the primary fuel source for the beneficial bacteria that live in your large intestine, your gut microbiome.[24][25]

When gut bacteria ferment fiber, they produce short-chain fatty acids (SCFAs), primarily acetate, propionate, and butyrate. These SCFAs have several important effects on glucose metabolism:

A study published in Science found that promoting a select group of SCFA-producing gut bacteria through a high-fiber diet improved HbA1c levels in patients with type 2 diabetes compared to a standard dietary approach.[26]

How much fiber do you need?

General recommendations vary by organization, but most agree on a range:

The Lancet authors noted that intakes above 25 to 29 g (0.9 to 1.0 oz) a day could bring further benefit, and the trials above used up to 50 g (1.8 oz) a day.[14] Individual tolerance varies. The key is to increase gradually. Adding too much fiber too quickly can cause bloating, gas, and abdominal discomfort.

A practical fiber-building schedule

Week 1 to 2: Add an extra 5 g (0.18 oz) a day (e.g., swap white rice for a cup of lentils, or add 2 tablespoons of chia seeds to your morning smoothie)

Week 3 to 4: Add another 5 g (0.18 oz) (e.g., include a serving of beans at lunch or snack on an apple with the skin)

Week 5 to 6: Add another 5 g (0.18 oz) (e.g., switch to oatmeal for breakfast, add broccoli or artichoke to dinner)

Ongoing: Continue building until you reach 30 to 40 g (1.1 to 1.4 oz) per day or your personal comfort level

Increase your water intake alongside your fiber intake. Fiber absorbs water as it moves through the digestive tract. Insufficient hydration can lead to constipation, which defeats the purpose. Aim for at least 8 glasses of water per day, and more if you are eating 35 g (1.2 oz) or more of fiber.

Practical tips to increase your daily fiber intake

The biggest barrier to eating more fiber is habit, not knowledge. Here are practical strategies that do not require you to overhaul your diet:

  1. Start your day with intact whole grains and seeds: swap refined cereal or white toast for steel-cut or rolled oats topped with berries and 1 oz (28 g) of chia seeds (10 g, or 0.35 oz, of fiber) or ground flaxseed (8 g, or 0.28 oz, of fiber).[4][13]
  2. Add beans, lentils or chickpeas to one meal a day: one cooked cup adds 12 to 19 g (0.42 to 0.67 oz) of fiber plus resistant starch; start with half a cup if you are new to legumes.[6][20]
  3. Eat whole fruits and unpeeled vegetables instead of drinking juice: an apple with its skin provides about 4.5 g (0.16 oz) of fiber (compared with 2.1 g, or 0.07 oz, peeled and almost none in juice), and raw vegetables with hummus make a 7 g (0.25 oz) fiber snack.[4][28]
  4. Use the "fiber first" meal order: eat non-starchy vegetables and protein before carbohydrates at main meals to reduce the post-meal glucose rise.[29]
  5. Build up by no more than 5 g (0.18 oz) a week and drink plenty of water so your gut adjusts comfortably.[4][14]

Fiber supplements: when food is not enough

Whole foods should always be the foundation of your fiber intake because they provide a matrix of nutrients, phytochemicals, and both fiber types together. Fiber supplements can still help when food falls short. Choose one that stays viscous through digestion to get a clinically meaningful benefit. That advice comes from a 2015 review written by an employee of Procter & Gamble, the maker of Metamucil.[30]

The most evidence-based fiber supplements for blood sugar management include:

When using supplements, keep these principles in mind:

  • Take them before or with meals, not on an empty stomach hours before eating
  • Start low, go slow to minimize digestive side effects
  • Drink plenty of water with every dose
  • Separate from medications by at least 2 hours because fiber can reduce the absorption of some drugs
  • Consult your healthcare provider before starting any supplement, especially if you take diabetes medications. The combination may cause blood sugar to drop more than expected

If you use insulin or a sulfonylurea such as gliclazide or glimepiride, adding a viscous fiber supplement like psyllium or glucomannan, or replacing refined carbohydrates with high-fiber legumes, can make your blood glucose fall too low unless your medicine plan is reviewed.[5][33] Low blood sugar usually means below 4 mmol/L (72 mg/dL) in the UK or below 70 mg/dL (3.9 mmol/L) in the US.[33][34] Our guide to low blood sugar covers the warning signs. In the UK, the NHS says to call 999 if someone may have very low blood sugar and is not responding normally or is unconscious, and a glucagon injection is not available or you do not know how to use it, or they have not recovered within 10 minutes of a glucagon injection, or they have been drinking alcohol.[33] In the US, the ADA says to call 911 right away if someone is unconscious and glucagon is not available or no one knows how to use it.[34]

What is the fiber "second meal effect"?

The second meal effect is one of the more interesting findings in fiber research. A high-fiber meal can improve your glucose response at that meal and at the next meal you eat, even hours later.

Research has shown that eating a high-fiber dinner (particularly one rich in legumes or barley) can reduce the glucose spike at breakfast the following morning.[35] This effect is thought to be mediated by the short-chain fatty acids produced when gut bacteria ferment the fiber overnight, which improve insulin sensitivity for the next meal.[36]

This matters in practice. Even if you cannot eat a perfectly balanced meal every time, a fiber-rich dinner can give you a metabolic buffer that carries into the next day.

Common mistakes when increasing fiber

Adding fiber is almost always a good move. A few pitfalls are worth avoiding:

  • Too much, too fast. Rapidly increasing fiber intake is the primary cause of bloating, gas, and cramping. Your gut bacteria need time to adjust. Increase by 5 g (0.18 oz) per week at most.
  • Not drinking enough water. Fiber without adequate hydration can cause constipation and abdominal discomfort. Increase water intake proportionally.
  • Relying on "fiber-enriched" processed foods. Products with added inulin, chicory root fiber or polydextrose can list a high fiber number. These isolated fibers dissolve in water but do not form a thick gel, and the post-meal glucose benefit comes mainly from viscous, gel-forming fibers like psyllium, beta-glucan and guar gum. So the fiber on the label may not give the same glycemic benefit as fiber from whole foods.[37][30]
  • Ignoring total carbohydrate content. A "high fiber" granola bar that also contains 30 g (1.1 oz) of sugar is not going to help your blood sugar. Look at the complete nutritional picture.
  • Forgetting about timing. Eating fiber alongside or before carbohydrates is more effective than eating it separately. The mechanical gel-forming effect requires the fiber and glucose-producing foods to be in the digestive tract at the same time.[29]

Fiber is not a quick fix. It works most reliably when you keep at it over time. The benefits build as your gut microbiome adapts, your eating habits shift and your baseline glucose control improves week by week.

Questions to ask your diabetes team

  • How many grams of fiber a day should I aim for, and how quickly should I build up?[3][4][27]
  • Can I take psyllium husk or another viscous fiber supplement, and how many hours apart from my prescribed tablets should I take it?[5][30]
  • If I add more beans, oats or a fiber supplement to my meals, do any of my insulin or sulfonylurea doses need to change to prevent hypos?[5][18][33]
  • Are there any reasons I should avoid a high-fiber diet, such as gastroparesis (delayed stomach emptying) or bowel narrowing?[1][27]

Frequently asked questions

Which type of fiber has the most direct effect on blood sugar?

Soluble, gel-forming fiber has the most direct effect. It mixes with water in the gut to slow stomach emptying and carbohydrate breakdown, which helps blunt the glucose rise after meals.[1][8]

How much fiber should I eat a day for blood sugar?

In the UK, the NHS advises 30 g (1.1 oz) a day for adults. In the US, the Institute of Medicine recommends 25 g (0.9 oz) for women and 38 g (1.3 oz) for men, and the ADA advises at least 14 g (0.5 oz) per 1,000 calories.[4][3][27]

Can I take psyllium husk with metformin or other diabetes medicines?

Ask your doctor or pharmacist first. Because psyllium forms a thick gel, take other medicines at least 2 hours before or after psyllium so it does not slow their absorption, and monitor for low blood sugar if you use insulin or other glucose medicines.[5]

Do fiber-enriched snack bars work the same as beans or oats?

Often, no. Many processed bars add non-viscous fibers such as inulin or chicory root, which do not form the thick gel needed to slow glucose absorption after a meal.[37][30]

Where to go next

For more on everyday food swaps, reading packet labels and checking your numbers, see:

Note: If you are pregnant, breastfeeding, or considering giving any supplement or herbal product to a child, consult your healthcare provider before making any changes to your diet, supplement routine, or prescribed medications.

Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Talk to your doctor before changing your diet, your activity or your medicines, and before starting any supplement.

Sources & References

  1. Dikeman CL, Fahey GC (2006). Viscosity as related to dietary fiber: a review. Critical Reviews in Food Science and Nutrition, 46(8):649-663. PMID: 17092830. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/17092830
  2. Jenkins DJ, Kendall CW, Axelsen M, Augustin LS, Vuksan V (2000). Viscous and nonviscous fibres, nonabsorbable and low glycaemic index carbohydrates, blood lipids and coronary heart disease. Current Opinion in Lipidology, 11(1):49-56. PMID: 10750694. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/10750694
  3. Trumbo P, Schlicker S, Yates AA, Poos M (2002). Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. Journal of the American Dietetic Association, 102(11):1621-1630. PMID: 12449285. Report of the US Institute of Medicine Food and Nutrition Board. pubmed.ncbi.nlm.nih.gov/12449285
  4. NHS (reviewed 13 July 2022). How to get more fibre into your diet. Checked 25 October 2026. nhs.uk
  5. Gibb RD, McRorie JW Jr, Russell DA, Hasselblad V, D'Alessio DA (2015). Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus. American Journal of Clinical Nutrition, 102(6):1604-1614. PMID: 26561625. Funded by Procter & Gamble; three authors were employees of Procter & Gamble (maker of Metamucil) and two reported consulting fees from P&G. pubmed.ncbi.nlm.nih.gov/26561625
  6. Sievenpiper JL, Kendall CW, Esfahani A, et al. (2009). Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia, 52(8):1479-1495. PMID: 19526214. Supported by Pulse Canada and the Canadian Institutes of Health Research; one author reported grants from food and nut industry boards. pubmed.ncbi.nlm.nih.gov/19526214
  7. Kim Y, Je Y (2016). Dietary fibre intake and mortality from cardiovascular disease and all cancers: a meta-analysis of prospective cohort studies. Archives of Cardiovascular Diseases, 109(1):39-54. PMID: 26711548. Supported by a National Research Foundation of Korea grant; the authors declared no conflict of interest. pubmed.ncbi.nlm.nih.gov/26711548
  8. Lattimer JM, Haub MD (2010). Effects of dietary fiber and its components on metabolic health. Nutrients, 2(12):1266-1289. PMID: 22254008. No external funding reported; the authors declared no conflict of interest (PMC full text). pubmed.ncbi.nlm.nih.gov/22254008
  9. Weickert MO, Pfeiffer AF (2008). Metabolic effects of dietary fiber consumption and prevention of diabetes. Journal of Nutrition, 138(3):439-442. PMID: 18287346. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/18287346
  10. Chandalia M, Garg A, Lutjohann D, von Bergmann K, Grundy SM, Brinkley LJ (2000). Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus. New England Journal of Medicine, 342(19):1392-1398. PMID: 10805824. Supported by US National Institutes of Health grants. Conflicts of interest not stated in the PubMed record. pubmed.ncbi.nlm.nih.gov/10805824
  11. Wanders AJ, van den Borne JJ, de Graaf C, et al. (2011). Effects of dietary fibre on subjective appetite, energy intake and body weight: a systematic review of randomized controlled trials. Obesity Reviews, 12(9):724-739. PMID: 21676152. Funded by Top Institute Food and Nutrition (Wageningen, Netherlands); one author was employed by Unilever R&D. pubmed.ncbi.nlm.nih.gov/21676152
  12. Canfora EE, Jocken JW, Blaak EE (2015). Short-chain fatty acids in control of body weight and insulin sensitivity. Nature Reviews Endocrinology, 11(10):577-591. PMID: 26260141. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/26260141
  13. Tosh SM (2013). Review of human studies investigating the post-prandial blood-glucose lowering ability of oat and barley food products. European Journal of Clinical Nutrition, 67(4):310-317. PMID: 23422921. Supported by Agriculture and Agri-Food Canada; the author declared no conflict of interest. pubmed.ncbi.nlm.nih.gov/23422921
  14. Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 393(10170):434-445. PMID: 30638909. Funded by the World Health Organization, Riddet Centre of Research Excellence and Health Research Council of New Zealand. The authors declared no competing interests. pubmed.ncbi.nlm.nih.gov/30638909
  15. Threapleton DE, Greenwood DC, Evans CE, et al. (2013). Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ, 347:f6879. PMID: 24355537. Funded by the UK Department of Health; the authors declared no competing interests (PMC full text). pubmed.ncbi.nlm.nih.gov/24355537
  16. Yao B, Fang H, Xu W, et al. (2014). Dietary fiber intake and risk of type 2 diabetes: a dose-response analysis of prospective studies. European Journal of Epidemiology, 29(2):79-88. PMID: 24389767. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/24389767
  17. Weickert MO, Pfeiffer AFH (2018). Impact of dietary fiber consumption on insulin resistance and the prevention of type 2 diabetes. Journal of Nutrition, 148(1):7-12. PMID: 29378044. Supported by the German Center for Diabetes Research (DZD); the authors declared no conflicts of interest. pubmed.ncbi.nlm.nih.gov/29378044
  18. Post RE, Mainous AG 3rd, King DE, Simpson KN (2012). Dietary fiber for the treatment of type 2 diabetes mellitus: a meta-analysis. Journal of the American Board of Family Medicine, 25(1):16-23. PMID: 22218620. The authors declared no conflicts of interest and no external funding. pubmed.ncbi.nlm.nih.gov/22218620
  19. Sierra M, Garcƭa JJ, FernƔndez N, Diez MJ, Calle AP (2002). Therapeutic effects of psyllium in type 2 diabetic patients. European Journal of Clinical Nutrition, 56(9):830-842. PMID: 12209371. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/12209371
  20. Jenkins DJ, Kendall CW, Augustin LS, et al. (2012). Effect of legumes as part of a low glycemic index diet on glycemic control and cardiovascular risk factors in type 2 diabetes mellitus: a randomized controlled trial. Archives of Internal Medicine, 172(21):1653-1660. PMID: 23089999. Funded by Saskatchewan Pulse Growers and the Canadian Institutes of Health Research; several authors reported grants from food and nut boards. pubmed.ncbi.nlm.nih.gov/23089999
  21. Higgins JA (2004). Resistant starch: metabolic effects and potential health benefits. Journal of AOAC International, 87(3):761-768. PMID: 15287677. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/15287677
  22. Li H, Zhang L, Li J, et al. (2024). Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota. Nature Metabolism, 6(3):578-597. PMID: 38409604. Funded by the National Natural Science Foundation of China and Chinese public science grants; the authors declared no competing interests (PMC full text). pubmed.ncbi.nlm.nih.gov/38409604
  23. Hu Y, Ding M, Sampson L, Willett WC, Manson JE, Wang M, Rosner B, Hu FB, Sun Q (2020). Intake of whole grain foods and risk of type 2 diabetes: results from three prospective cohort studies. BMJ, 370:m2206. PMID: 32641435. Funded by US National Institutes of Health grants; the authors declared no competing interests (PMC full text). pubmed.ncbi.nlm.nih.gov/32641435
  24. Zhao L (2013). The gut microbiota and obesity: from correlation to causality. Nature Reviews Microbiology, 11(9):639-647. PMID: 23912213. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/23912213
  25. Sonnenburg JL, BƤckhed F (2016). Diet-microbiota interactions as moderators of human metabolism. Nature, 535(7610):56-64. PMID: 27383980. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/27383980
  26. Zhao L, Zhang F, Ding X, et al. (2018). Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes. Science, 359(6380):1151-1156. PMID: 29590046. Funded by the National Natural Science Foundation of China; one author is a co-founder of Notitia Biotechnologies. pubmed.ncbi.nlm.nih.gov/29590046
  27. Evert AB, Dennison M, Gardner CD, et al. (2019). Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report. Diabetes Care, 42(5):731-754. PMID: 31000505. Supported by the American Diabetes Association; authors reported disclosures at the end of the report. pubmed.ncbi.nlm.nih.gov/31000505
  28. Muraki I, Imamura F, Manson JE, et al. (2013). Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies. BMJ, 347:f5001. PMID: 23990623. Supported by US National Institutes of Health grants; one author reported grants from the California Strawberry Commission and the California Walnut Commission outside the submitted work. pubmed.ncbi.nlm.nih.gov/23990623
  29. Shukla AP, Iliescu RG, Thomas CE, Aronne LJ (2015). Food order has a significant impact on postprandial glucose and insulin levels. Diabetes Care, 38(7):e98-e99. PMID: 26106234. Supported by the Clinical and Translational Science Center at Weill Cornell Medical College; one author reported consulting fees and equity in weight-management and pharmaceutical companies. pubmed.ncbi.nlm.nih.gov/26106234
  30. McRorie JW Jr (2015). Evidence-based approach to fiber supplements and clinically meaningful health benefits, part 1: what to look for and how to recommend an effective fiber therapy. Nutrition Today, 50(2):82-89. PMID: 25972618. Funded by Procter & Gamble; the author was an employee of Procter & Gamble (maker of Metamucil). pubmed.ncbi.nlm.nih.gov/25972618
  31. Sood N, Baker WL, Coleman CI (2008). Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. American Journal of Clinical Nutrition, 88(4):1167-1175. PMID: 18842808. No external funding reported; the authors declared no conflict of interest. pubmed.ncbi.nlm.nih.gov/18842808
  32. Groop PH, Aro A, Stenman S, Groop L (1993). Long-term effects of guar gum in subjects with non-insulin-dependent diabetes mellitus. American Journal of Clinical Nutrition, 58(4):513-518. PMID: 8397484. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/8397484
  33. NHS (reviewed 3 August 2023). Low blood sugar (hypoglycaemia). Checked 25 October 2026. nhs.uk
  34. American Diabetes Association. Hypoglycemia (Low Blood Glucose). Checked 25 October 2026. diabetes.org
  35. Brighenti F, Benini L, Del Rio D, et al. (2006). Colonic fermentation of indigestible carbohydrates contributes to the second-meal effect. American Journal of Clinical Nutrition, 83(4):817-822. PMID: 16600933. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/16600933
  36. Nilsson AC, Ostman EM, Holst JJ, Bjƶrck IM (2008). Including indigestible carbohydrates in the evening meal of healthy subjects improves glucose tolerance, lowers inflammatory markers, and increases satiety after a subsequent standardized breakfast. Journal of Nutrition, 138(4):732-739. PMID: 18356328. Funding and conflicts of interest not stated in the PubMed record; full text not checked. pubmed.ncbi.nlm.nih.gov/18356328
  37. Stephen AM, Champ MM, Cloran SJ, et al. (2017). Dietary fibre in Europe: current state of knowledge on definitions, sources, recommendations, intakes and relationships to health. Nutrition Research Reviews, 30(2):149-190. PMID: 28676135. Commissioned by ILSI Europe Dietary Carbohydrates Task Force (industry-supported); several authors reported grants or consulting ties to food companies. pubmed.ncbi.nlm.nih.gov/28676135
Back to blog