A six-month trial suggests that limiting eating window may improve blood glucose management for some adults with Type 1 diabetes, without immediate safety risks, prompting calls for larger studies.
A six-month randomised trial led by researchers at the University of Illinois Chicago suggests that time-restricted eating may help some adults with Type 1 diabetes improve blood-sugar control without adding obvious short-term safety risks, according to findings published in Diabetes Care. The study, led by Krista Varady, adds to a small but growing body of evidence that the timing of meals may matter as much as calorie intake for certain people living with the condition.
The trial enrolled 32 adults from the Chicago area who had Type 1 diabetes and obesity, and divided them into three groups. One group ate only between noon and 8 p.m. without counting calories, another reduced daily energy intake by 25%, and a third made no planned dietary changes. The aim was to see whether restricting the eating window could influence glucose control independently of deliberate calorie reduction.
After six months, the group following the eight-hour schedule recorded a larger fall in glycated haemoglobin, or HbA1c, than the calorie-restriction group. HbA1c reflects average blood sugar over roughly two to three months, making it a standard measure of diabetes management. In this trial, the average improvement was about 0.5 percentage points, a result that researchers said could be clinically meaningful if confirmed in larger studies.
The findings are notable because fasting can be more complicated in Type 1 diabetes than in Type 2, where the body still makes insulin. People who depend on insulin replacement must balance food intake, dosing and glucose monitoring carefully, since too little insulin can lead to diabetic ketoacidosis and too much can trigger dangerous hypoglycaemia. Within the limits of the study, the researchers reported no increase in either extreme high or low blood-sugar events in the time-restricted eating group, and no rise in diabetic ketoacidosis.
Previous research has hinted that fasting may be feasible in some people with Type 1 diabetes when monitoring is close and education is structured. A 2019 study in Frontiers in Endocrinology and a later 2021 paper in the same field both suggested that supervised fasting periods could be tolerated safely, while a 2024 review in Trends in Endocrinology & Metabolism said intermittent fasting may have potential for adults with obesity and Type 1 diabetes. Even so, the UIC trial remains early evidence: it was small, limited to adults from one area and did not test long-term effects on complications, nutrition or quality of life. The researchers say larger studies are needed, and clinicians advise anyone with Type 1 diabetes to seek medical guidance before changing meal timing.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
