Intermittent Fasting Can Help People with Type 2 Diabetes Lose Weight and Control Their Blood Sugar Levels

Today, 1 in 10 U.S. residents has diabetes, and that number is expected to rise to 1 in 3 by 2050 if current trends continue, the researchers explain. Finding more options for controlling weight and blood sugar levels for these patients, therefore, is crucial.

Time-restricted eating, also known as intermittent fasting, can help people with Type 2 diabetes lose weight and control their blood sugar levels, according to a new study published in JAMA Network Open from researchers at the University of Illinois Chicago.

Participants who ate only during an eight-hour window between noon and 8 p.m. each day actually lost more weight over six months than participants who were instructed to reduce their calorie intake by 25%. Both groups had similar reductions in long-term blood sugar levels, as measured by a test of hemoglobin A1C, which shows blood sugar levels over the past three months.

The study enrolled 75 participants into three groups: those who followed the time-restricted eating rules, those who reduced calories and a control group. 

“Our study shows that time-restricted eating might be an effective alternative to traditional dieting for people who can’t do the traditional diet or are burned out on it,” said Varady, a professor of kinesiology and nutrition. “For many people trying to lose weight, counting time is easier than counting calories.”

There were no serious adverse events reported during the six-month study. 

Just over half the participants in the study were Black and another 40% were Hispanic. This is notable as diabetes is particularly prevalent among those groups, so having studies that document the success of time-restricted eating for them is particularly useful, the researchers said.

The study was small and should be followed up by larger ones, said Varady, who is also a member of the University of Illinois Cancer Center. While it acts as a proof of concept to show that time-restricted eating is safe for those with Type 2 diabetes, Varady said people with diabetes should consult their doctors before starting this sort of diet.


Vasiliki Pavlou, Sofia Cienfuegos, Shuhao Lin, Mark Ezpeleta, Kathleen Ready, Sarah Corapi, Jackie Wu, Jason Lopez, Kelsey Gabel, Lisa Tussing-Humphreys, Vanessa M. Oddo, Shaina J. Alexandria, Julienne Sanchez, Terry Unterman, Lisa S. Chow, Alaina P. Vidmar, Krista A. Varady. Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes. JAMA Network Open, 2023; 6 (10): e2339337 DOI: 10.1001/jamanetworkopen.2023.39337

University of Illinois Chicago. “Intermittent fasting is safe, effective for those with Type 2 diabetes, study suggests.” ScienceDaily. ScienceDaily, 27 October 2023. <>.

Materials provided by University of Illinois Chicago. Original written by Emily Stone. Note: Content may be edited for style and length.

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Photo by Tim Wildsmith