This article originally appeared on Medical News Today
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Dietary changes are a crucial component of managing type 2 diabetes and can even help achieve remission of the disease.
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Fasting diets, which involve calorie restriction during specific hours or days, have been shown to be effective in alleviating symptoms of type 2 diabetes.
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A previous randomized controlled trial demonstrated that a monthly cycle of a fasting-mimicking diet that limits calorie intake during five consecutive days can lower blood sugar levels and reduce reliance on medications.
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Data from a recent study provides real-world evidence to support the effectiveness of a 5-day fasting-mimicking diet, beyond the controlled conditions of a clinical trial.
About 11% of the American population had diabetes in 2021, with type 2 diabetes accounting for 90% to 95% of these cases.
Fasting diets, which involve alternating periods of fasting and eating, are effective in alleviating the symptoms of type 2 diabetes and can be easier to follow than reducing daily calorie intake over a long time.
A new study, conducted using real-world evidence, shows that individuals with type 2 diabetes who follow a fasting diet involving restricted energy intake for 5 consecutive days per month exhibit improvements in blood glucose (sugar) levels, weight loss, and a reduced reliance on diabetes medications.
This fasting program has been patented by L-Nutra, a nutrient technology company. One of the study authors, William Hsu, MD, an endocrinologist and Chief Medical Officer at L-Nutra, told Medical News Today that:
“This study demonstrates how the fasting-mimicking diet (FMD), when combined with physician oversight and registered dietitian (RD) coaching, can be safely and effectively implemented in real-world clinical settings to manage type 2 diabetes.”
The researchers presented these results at the American Diabetes Association’s 85th Scientific Sessions on June 20, 2025. The findings are yet to appear in a peer-reviewed journal.
How do fasting diets work?
The treatment for type 2 diabetes typically involves a combination of lifestyle modifications and medications. Lifestyle modifications, including dietary changes and increased physical activity, help lower blood glucose levels and facilitate weight loss.
While medications such as metformin and GLP-1 agonists facilitate the management of diabetes symptoms, only lifestyle changes, such as dietary modifications, can lead to disease remission.
Studies have shown that restricting daily calorie intake is effective in managing blood sugar levels and reducing weight in individuals with type 2 diabetes. However, adhering to such a diet over the long term is challenging.
Additionally, the body adapts to long-term calorie restriction, resulting in a slower metabolism, which makes sustained weight loss more challenging.
Instead, various forms of fasting diets, involving alternating periods of fasting and unrestricted food intake, have been suggested to be easier to adhere to while alleviating diabetes symptoms.
Fasting triggers a stress response in cells and the body, promoting healthy aging by reducing inflammation and oxidative damage, while enhancing metabolism.
Fasting diets may involve either restricting calorie intake during certain hours of the day, known as intermittent fasting, or during specific days of the week or month, referred to as periodic fasting.
The fasting-mimicking diet is a form of periodic fasting that involves restricted calorie intake for 4 to 7 consecutive days per month.
Researchers have developed the fasting mimicking diet to simulate the beneficial health effects of water-only fasting, which involves only water intake during a 24 to 72-hour period. In contrast to water-only fasting, a fasting-mimicking diet allows for limited calorie intake during the fasting period, making adherence less challenging.
Blood sugar control: How is a 5-day fasting approach better?
The authors of the current study have developed a patented low-calorie, plant-based diet that is low in sugar and protein, but rich in healthy unsaturated fats and fiber.
A previous study demonstrated that a 5-day fasting-mimicking diet also leads to a decrease in blood sugar and insulin levels, while increasing the levels of ketone bodies.
Moreover, a recent randomized controlled trial demonstrated that a 5-day fasting mimicking diet combined with medications was more effective than medications alone in improving blood glucose control and reducing medication reliance.
These results were observed under highly controlled conditions in a clinical trial, including strict criteria for patient inclusion and exclusion. This makes it essential to evaluate the real-world efficacy of this intervention.
Real-world impact of a fasting-mimicking diet
In the present study, researchers evaluated the real-world benefits of integrating a fasting-mimicking diet into routine care for individuals with type 2 diabetes.
The present study included data from patients enrolled in a diabetes management program that involved following a monthly 5-day fasting-mimicking diet under the supervision of physicians and registered dietitians.
Patients were enrolled in the study on a rolling basis, and data were collected from those who had completed at least 3 or 6 months of the program.
At the end of 3 and 6 months, the fasting-mimicking diet was effective in facilitating weight loss and reducing glycated hemoglobin levels, a marker of blood glucose levels. The fasting-mimicking diet also helped a greater percentage of participants achieve blood glucose control at these time points than at the time of enrolment.
The fasting-mimicking diet also reduced reliance on medications for blood glucose control, while still resulting in high levels of engagement in the program.
In addition, Hsu noted:
“Most participants are able to integrate the fasting-mimicking diet into their daily lives without significant disruption. Because it’s a 5-day monthly intervention rather than a daily regimen, many find it feasible to complete even with work and family obligations, especially with RD support to tailor practical strategies for adherence and personalization.”
While the fasting-mimicking diet can be safely undertaken by most individuals with type 2 diabetes, patients should consult a physician before starting such a diet.
Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian and heart health expert at Entirely Nourished, not involved in this study, expressed some caution about the findings.
“While the positive effects of the FMD program on weight and HbA1c [a marker of blood sugar] are promising, it is important to note that the intervention was associated with common signs of energy deficit — including fatigue, headache, dizziness, and nausea — in a substantial number of participants during the 5-day fasting period,“ Routhenstein told MNT.
“Although these symptoms resolved between cycles, they may pose risks for certain individuals, especially those with coexisting health conditions or frailty,“ she pointed out.
Hsu also cautioned that: “While the program accommodates most individuals with type 2 diabetes or metabolic syndrome, certain conditions are exclusionary, such as recent cardiovascular events, end-stage diabetes complications, frailty, a BMI under 18, or allergies to FMD ingredients. The program is designed to prioritize safety while expanding access to innovative nutrition-based care for metabolic health.”
Finally, Routhenstein advised that “the inclusion of lifestyle advice with the option to consult a dietitian may have influenced some of the study findings.”
View the original article on Medical News Today