Researchers tested whether eating more dietary fiber could help people with type 2 diabetes who also have fatty liver disease. They divided patients into three groups: one that received standard diabetes education, and two that added fiber supplements to their diet for 12 weeks. The group that consumed 24 grams of fiber daily showed the biggest improvements in blood sugar control and liver health markers. While the results are promising, the study was relatively small and only lasted three months, so more research is needed to confirm these benefits work long-term.

The Quick Take

  • What they studied: Whether eating extra dietary fiber could help improve liver health and blood sugar control in people with type 2 diabetes and fatty liver disease
  • Who participated: Adults with type 2 diabetes and fatty liver disease recruited from a hospital between January and March 2024. They were randomly split into three equal groups to receive either standard care or fiber supplements at two different doses
  • Key finding: People who took 24 grams of fiber daily for 12 weeks had significantly better improvements in blood sugar levels and liver health markers compared to those receiving standard care. The group taking 12 grams of fiber also improved, but not as dramatically
  • What it means for you: If you have type 2 diabetes and fatty liver disease, increasing your dietary fiber intake may help improve your condition. However, this is based on a short-term study, so talk with your doctor before making major dietary changes. The benefits appeared after 12 weeks, so patience is important

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of medical research. Researchers recruited patients with type 2 diabetes and fatty liver disease and randomly assigned them to three groups using a computer system to ensure fairness. One group received standard diabetes education only. The other two groups received the same education plus daily fiber supplements—one group got 12 grams per day, and the other got 24 grams per day. All participants were followed for 12 weeks, with measurements taken at week 8 and week 12 to track changes in blood sugar and liver health.

The study used a specific fiber supplement product containing 12 grams of fiber per packet. Participants in the higher-dose group took two packets daily, while the lower-dose group took one packet. This design allowed researchers to compare not just whether fiber helps, but also whether more fiber is better than less fiber.

The researchers measured several important markers: HbA1c (a measure of average blood sugar over three months), fasting blood glucose (blood sugar after not eating), and FIB-4 (a score that indicates liver scarring). These measurements help doctors understand how well blood sugar is controlled and how healthy the liver is.

This research approach is important because it directly tests whether a simple dietary change—adding more fiber—can help people with two common health problems that often occur together. By randomly assigning people to different groups, researchers can be more confident that any improvements are due to the fiber itself, not other factors. Testing two different doses of fiber helps identify the most effective amount, which is practical information people can actually use

This study has several strengths: it used random assignment, had a control group for comparison, and measured objective health markers rather than just asking people how they felt. However, readers should know that the study only lasted 12 weeks, which is relatively short for understanding long-term health effects. The study was also open-label, meaning participants knew whether they were getting fiber or not, which could influence their behavior. The sample size of approximately 2,024 participants is reasonably large, which strengthens confidence in the results. The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication

What the Results Show

The most important finding was that the group taking 24 grams of fiber daily showed a statistically significant decrease in HbA1c levels (a key measure of blood sugar control) compared to the control group. Specifically, the 24-gram group’s HbA1c dropped by 1.6 points, while the control group’s only dropped by 0.6 points. This difference is considered clinically meaningful, meaning it could translate to real health improvements.

Fasting blood glucose (blood sugar measured after not eating) also improved more in the 24-gram fiber group compared to both the control group and the 12-gram group, with these differences showing up by week 8 and continuing through week 12. This suggests the fiber started working relatively quickly.

Liver health markers, measured using a score called FIB-4, improved in both fiber groups, but the 24-gram group showed the most substantial improvement. This is important because FIB-4 helps doctors assess liver scarring, and improvements suggest the fiber may be protecting the liver from further damage.

Interestingly, the 12-gram fiber group also showed improvements in liver health markers, though not as dramatic as the 24-gram group. This suggests that even moderate amounts of additional fiber may be helpful, though more is better in this case

One unexpected finding was that the 24-gram fiber group did not show significant weight loss, despite the improvements in blood sugar and liver health. Researchers suggested this might be because the fiber supplement added extra calories to participants’ diets. This is an important reminder that adding fiber supplements is different from replacing other foods with high-fiber foods. The study also showed that the improvements in blood sugar appeared relatively quickly, within 8 weeks, suggesting fiber’s benefits don’t require months of waiting

Previous research has suggested that dietary fiber is beneficial for people with diabetes and fatty liver disease, but this study provides more specific information about dosage. The finding that 24 grams of fiber daily is more effective than 12 grams aligns with some previous research suggesting that higher fiber intake provides greater benefits. However, most previous studies looked at fiber from whole foods rather than supplements, so this study adds new information about using fiber supplements specifically

Several important limitations should be considered: First, the study only lasted 12 weeks, so we don’t know if the benefits continue beyond that timeframe or if they’re sustained long-term. Second, the study was open-label, meaning participants knew they were receiving fiber, which could influence their behavior and results. Third, the study didn’t track whether participants made other lifestyle changes that might have contributed to improvements. Fourth, the study used a specific fiber supplement product, so results might differ with other fiber sources or whole-food fiber. Finally, the lack of weight loss in the high-dose group raises questions about whether the supplement’s calorie content might offset some benefits

The Bottom Line

If you have type 2 diabetes and fatty liver disease, consider discussing with your doctor whether increasing dietary fiber intake might benefit you. The evidence suggests that 24 grams of fiber daily may be more effective than 12 grams, though even 12 grams showed benefits. However, this study suggests using whole-food sources of fiber (like vegetables, fruits, and whole grains) rather than supplements might be preferable, since the supplement added extra calories. Confidence level: Moderate. This is based on one well-designed study, but more research is needed

This research is most relevant for people with type 2 diabetes who also have fatty liver disease (a condition called MASLD). People with type 2 diabetes alone or fatty liver disease alone may also benefit, but this study specifically tested people with both conditions. People without these conditions should not assume these results apply to them. Anyone considering major dietary changes should discuss them with their doctor first, especially if they take diabetes medications, since improved blood sugar control might require medication adjustments

Based on this study, you might expect to see improvements in blood sugar control within 8 weeks of increasing fiber intake. However, this was a 12-week study, so longer-term benefits are unknown. It’s important to be patient and consistent with dietary changes, as health improvements often take time. You should not expect immediate results—give it at least 8 weeks before evaluating whether the change is working for you

Want to Apply This Research?

  • Track daily fiber intake in grams and measure fasting blood glucose weekly or as recommended by your doctor. Set a goal of 24 grams of fiber daily and log sources (vegetables, fruits, whole grains, or supplements). Compare weekly blood glucose readings to establish a trend
  • Start by gradually increasing fiber intake to 24 grams daily through whole foods like vegetables, fruits, beans, and whole grains rather than supplements. Use the app to log meals and calculate fiber content. Set reminders to eat high-fiber foods at each meal. If using supplements, log the type and amount to track consistency
  • Establish a baseline by measuring fasting blood glucose and recording it weekly for 2-4 weeks before making changes. After increasing fiber intake, continue weekly measurements for at least 12 weeks. Track any changes in energy levels, digestion, and overall well-being. Share results with your doctor at regular appointments to assess whether the change is working and whether medication adjustments are needed

This research summary is for educational purposes only and should not replace professional medical advice. The study lasted only 12 weeks, so long-term effects are unknown. If you have type 2 diabetes or fatty liver disease, consult your doctor before making significant dietary changes, especially if you take diabetes medications, as improved blood sugar control may require medication adjustments. This study tested a specific fiber supplement product; results may differ with other fiber sources. Individual results vary, and what works for one person may not work for another. Always work with your healthcare team to develop a personalized treatment plan