A study presented at ENDO 2025 comparing three popular diets (intermittent fasting, time-restricted eating, and continuous calorie cutting) suggests that they all can help those with type 2 diabetes lower blood sugar levels and lose weight.
However, the 5:2 intermittent fasting plan was found to stand out among the three plans, leading to better results in fasting blood sugar levels and insulin response among those adhering to the plan. (The 5:2 plan involves eating normally for 5 days a week and restricting caloric intake for 2 days.)
“This study is the first to compare the effects of three different dietary interventions: intermittent energy restriction (IER), time-restricted eating (TRE) and continuous energy restriction (CER) in managing type 2 diabetes with obesity,” said Haohao Zhang, Ph.D., chief physician at The First Affiliated Hospital of Zhengzhou University in Zhengzhou, China.
Examining dietary interventions against type 2 diabetes
For this study, a single-center, randomized, parallel-controlled trial was conducted at the First Affiliated Hospital of Zhengzhou University from November 19, 2021, to November 7, 2024. A team of nutritionists supervised the 16-week intervention. 90 participants were randomly assigned in a 1:1:1 ratio to the IER, TRE, or CER group, with consistent weekly caloric intake across all groups.
The intermittent fasting group had the highest adherence rate (85%), followed by the CER group at 84% and the TRE group at 78%. Both the IER and CER groups showed statistically significant differences compared with the TRE group.
Of the 90 participants enrolled, 63 completed the study with an average age of 36.8 years old, a mean diabetes duration of 1.5 years, a baseline BMI of 31.7 kg/m², and an HbA1c of 7.42%. Compared to TRE and CER, IER significantly reduced fasting blood glucose and triglycerides and increased the Matsuda index, a measure of whole-body insulin sensitivity. Uric acid and liver enzyme levels exhibited no statistically significant changes from baseline in any study group.
While improved HbA1c levels and adverse events were found to be similar across the three groups, the intermittent fasting group showed greater advantages in reducing fasting blood glucose, improving insulin sensitivity, lowering triglycerides, body weight, and strengthening adherence to the dietary interventions, according to the researchers.
“The research fills a gap in directly comparing 5:2 intermittent energy restriction with a 10-hour time-restricted eating in patients with obesity and type 2 diabetes. The findings provide scientific evidence for clinicians to choose appropriate dietary strategies when treating such patients,” Zhang said.
The researchers believe that these findings demonstrate the feasibility and effectiveness of dietary interventions for those with obesity and type 2 diabetes, particularly the 5:2 intermittent fasting plan.
Obesity and type 2 diabetes at a glance
According to the Centers for Disease Control and Prevention (CDC), as of 2021, an estimated 38.4 million adults in the United States (11.6%) had been diagnosed with diabetes. Of these, approximately 90-95% (34.6-36.5 million) had type 2 diabetes.
Globally, the International Diabetes Federation (IDF) estimates that over 537 million adults aged 20-79 years had diabetes in 2021. This number is projected to increase to 643 million by 2030 and 783 million by 2045.
It’s important to note that these figures may underestimate the actual number of people with type 2 diabetes, as many cases go undiagnosed.
According to the Centers for Disease Control and Prevention (CDC), as of 2023, approximately 40.3% of adults in the United States have obesity. This translates to over 100 million people.
Globally, the World Health Organization (WHO) estimates that over 1 billion people are obese, and this number is expected to increase to reach over 2 billion by 2030. Women are more likely to be obese than men, and the prevalence of obesity is highest among adults aged 40-59. Racial and ethnic minorities have higher rates of obesity than White Americans. Children and adolescents are also increasingly affected by obesity, with an estimated 1 in 5 children being overweight or obese.
As with anything you read on the internet, this article should not be construed as medical advice; please talk to your doctor or primary care provider before changing your wellness routine. WHN does not agree or disagree with any of the materials posted. This article is not intended to provide a medical diagnosis, recommendation, treatment, or endorsement. Additionally, it is not intended to malign any religion, ethnic group, club, organization, company, individual, or anyone or anything. These statements have not been evaluated by the Food and Drug Administration.
