A new study compared three popular diet strategies—intermittent fasting, time-restricted eating, and continuous calorie-cutting—to see which worked best for people with type 2 diabetes and obesity.
While all three helped with weight loss and blood sugar, the twice-a-week fasting plan (also known as the 5:2 diet) delivered the strongest improvements in blood sugar levels and insulin response. It also had the highest success rate for sticking with the plan. The findings suggest that skipping meals just two days a week might be a powerful, manageable way to improve health.
Comparing Three Diet Strategies for Diabetes
A recent study presented at ENDO 2025, the Endocrine Society’s annual meeting in San Francisco, California, found that three popular dietary approaches—intermittent energy restriction, time-restricted eating, and continuous energy restriction—can all help lower blood sugar levels and support weight loss in people with obesity and type 2 diabetes.
“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.
All three groups showed improvement in long-term blood sugar control (HbA1c), and side effects were similar across the board. However, participants following the IER plan experienced more notable benefits, including better fasting blood sugar levels, enhanced insulin sensitivity, lower triglycerides, and stronger adherence to the diet.
“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.
Trial Details and Participant Profile
Zhang and colleagues performed a single-center, randomized, parallel-controlled trial at the First Affiliated Hospital of Zhengzhou University from November 19, 2021, to November 7, 2024.
Ninety patients were randomly assigned in a 1:1:1 ratio to the IER, TRE or CER group, with consistent weekly caloric intake across all groups. A team of nutritionists supervised the 16-week intervention.
Of those enrolled, 63 completed the study. There were 18 females and 45 males, with an average age of 36.8 years, a mean diabetes duration of 1.5 years, a baseline BMI of 31.7 kg/m2, and an HbA1c of 7.42%.
Results Favor Intermittent Energy Restriction
At the end of the study, there were no significant differences in HbA1c reduction and weight loss between the IER, TRE, and CER groups. However, the absolute decrease in HbA1c and body weight was greatest in the IER group.
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.
Two patients in the IER group and the TRE group, and three patients in the CER group, experienced mild hypoglycemia.
Adherence and Clinical Implications
The IER 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.
Zhang said these findings highlight the feasibility and effectiveness of dietary interventions for people who have obesity and type 2 diabetes.
Meeting: ENDO 2025
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11 Comments
The only sustainable diet that can completely reverse insulin resistance ( which can only reliably measured clinically with an Oral Glucose Tolerance test and not HbA1c ) hence Type 2 diabetes, which has been shown and known for almost 100 years to be due to saturated fat in the diet, in 100% of cases is a very low fat ( less than 15% of Calories by fat ) whole plant starch based diet as shown by the late Dr John Mcdougall international icon of the whole plant based movement.
Dr. Arrizza, as a now 81 year old bald headed, chubby, lay American male who’s been battling mostly mild (now) FDA instigated chronic illnesses since early 1981 with no blood glucose problems until very recently and mostly untreated (bad side effects) high blood pressure since 1992, who still ingests animal food products and is still free of any regular prescription treatments, I just searched Dr. John Mcdougall and found he died in his sleep last year at age 77. It appears he was doing something wrong. Like myself in 1980 and like you presently (it seems), he probably was unaware of a (my) kind of nearly subclinical non-IgE-mediated food allergies (e.g., Dr. Arthur F. Coca, by 1935) aggravated (or not) with FDA approved food poisoning (e.g., soy [late 1960s], TBHQ [1972] and MSG [1980], minimally, the US diabetes epidemic presented by 1994, CDC data). Your photo suggests to me if you want to continue to extend your retirement, indefinitely, then you still need to learn of your own sub-acute allergies and wean yourself off of any toxic prescription meds you are taking. Not a healthcare professional of any kind, I find that the three most ‘obvious’ common symptoms of my kind of allergies (long-term, months to decades, highly individual) are 1) obesity, 2) so-called “male-pattern-baldness” and 3) eyeglasses for myopia. More details: https://odysee.com/@charlesgshaver:d?view=about
Dr Mcdougall had a major stroke at the age of 18 due to the toxic high fat diet he ate at the time. Unlike many people who are debilitated and who often live short lives after such an event he went on to live another 60 years in good health, became a respected internationally recognized physician who discovered the underlying cause and solution to up to 80% of all preventable chronic medical conditions, many of the same ones you’ve outlined, and helped tens of thousands of individuals get back their health. As for me at 69 I’ve never been healthier, am on no medications, have no medical conditions, am in the best shape of my life and am playing intermediate level pickleball and beating players less than half my age. I attribute this largely to Dr Mcdougall’s recommendations, which I’ve followed for at least a decade and which helped me reverse several conditions myself. Thanks for your input and be well!
Thank you for the kind and informative reply. A little searching informed me that prior to retiring you were a doctor of some renown too. I’m not much inclined to argue with success except for my rare (if not unique) experiences with my kind of allergies, at-home experiments and lay findings, with little publication. If you are still active, at all, I may be able to add to your expertise with a few discoveries of my own. I can be reached through my ad-free video channel (https://odysee.com/@charlesgshaver:d?view=about). Likewise, be safe; be well.
Thanks for the link Charles and congratulations on your insight on the MSG issue! Yes, I agree, a major toxin worth avoiding and the reason I avoid all processed foods. You may be interested in checking out Dr Peter Rogers’s YT site, a protege of Dr Mcdougall. He covers this as well as many other neuro and mitochondrial toxins that I think you’ll find enlightening. Be well!
With regards to my previous statement on MSG I wish to amend it by saying that some people seem to experience sensitivity to it and that others less so. Apparently rigorous studies “proving” its toxicity have been recommended but still need to be done. Dr Peter Rogers is a more reliable source of information on this matter than I. Thanks!
An 18 year old does not have a stroke from his diet, especially a diet 60 years ago. Our food supply was not tainted like it is now.
That’s exactly what I was thinking when I read it!
Mr. Charles and Dr. Nick,
I enjoyed reading your comments. It would be great if more people would go back and forth with each other in such a respectable and informed fashion!
Thank you Suzi; agreed. And, I have begun to check out Dr. Rogers on MSG as “Dr. Nick” suggested. I find that undiagnosed sub-acute food allergies are what makes the sensitivity difference.
“Hello, Doctor Nick!” Riviera, I presume?