Eating Oatmeal for Two Days Has Unexpected Impact on Heart Health, Study Suggests

German study finds eating oats for just two days can lower "bad" cholesterol by 10% and reduces diabetes risk in people with metabolic syndrome.

Published on Feb. 22, 2026

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A recent study from the University of Bonn in Germany found that eating oatmeal for just two days can have a significant impact on cholesterol levels and diabetes risk. The study involved 32 adults with metabolic syndrome, who consumed a calorie-reduced diet of almost exclusively oatmeal for two days. The results showed a 10% reduction in LDL or "bad" cholesterol levels, as well as an average weight loss of 2 kilos and a slight drop in blood pressure.

Why it matters

This study suggests that a short-term oat-based diet could be an effective and well-tolerated way to manage cholesterol levels and prevent diabetes, especially for those with metabolic syndrome. The findings highlight the potential health benefits of incorporating oats into one's diet, even for a brief period.

The details

Researchers had the 32 participants eat oatmeal, previously boiled in water, three times a day, for a total of 300 grams. They were only permitted to add fruits or vegetables to their meals and consumed around half of their normal caloric intake. A control group was put on a calorie-reduced diet that did not include oats. The study found that the cholesterol levels of those on the oat diet "improved significantly" and this effect "remained stable" after six weeks. The authors concluded that the diet influenced microorganisms in the gut, leading to the positive reaction.

  • The study was conducted by researchers from the University of Bonn in Germany.
  • The results were published in the journal Nature Communications.

The players

Marie-Christine Simon

Junior professor at the Institute of Nutritional and Food Science at the University of Bonn and the study's lead author.

Robin DeCicco

A certified holistic nutritionist who was not involved in the study but commented on the findings.

Megan Wroe

A registered dietitian at the Wellness Center at Providence St. Jude Medical Center in Orange County, California, who also commented on the study.

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What they’re saying

“That is a substantial reduction, although not entirely comparable to the effect of modern medications. They also lost two kilos in weight on average, and their blood pressure fell slightly.”

— Marie-Christine Simon, Junior professor at the Institute of Nutritional and Food Science at the University of Bonn (University of Bonn press release)

“The more beneficial gut bacteria you have in your stomach, in your environment, the more that can reduce or inhibit the production of LDL bad cholesterol.”

— Robin DeCicco, Certified holistic nutritionist (Fox News Digital)

“Knowing this, my recommendation is to eat oats as often as you like, choosing steel-cut or rolled oats, using fruit for sweetness, or a low-glycemic sweetener if needed, such as monk fruit.”

— Megan Wroe, Registered dietitian at the Wellness Center at Providence St. Jude Medical Center (Fox News Digital)

What’s next

As a next step, it can now be clarified whether an intensive oat-based diet repeated every six weeks actually has a permanently preventative effect, according to study author Marie-Christine Simon.

The takeaway

This study highlights the potential heart health benefits of incorporating oats into one's diet, even for a brief period of time. The findings suggest that a short-term oat-based diet could be an effective and well-tolerated way to manage cholesterol levels and prevent diabetes, especially for those with metabolic syndrome.