A small University of Illinois Chicago trial indicates that limiting eating to an eight-hour window may help some adults with type 1 diabetes improve blood glucose management safely, sparking cautious optimism for wider application.
A small clinical trial from the University of Illinois Chicago suggests that limiting eating to an eight-hour window may help some adults with type 1 diabetes improve blood sugar control without adding short-term safety risks.
The findings, published in Diabetes Care and also presented at the American Diabetes Association’s 2026 meeting, come from a six-month study of 32 adults with type 1 diabetes and obesity. Participants were randomly assigned to time-restricted eating, a daily calorie-cutting plan or their usual routine. In the time-restricted group, eating was confined to noon to 8 p.m., with no calorie counting required.
Researchers led by Krista Varady, a University of Illinois Chicago professor who has long studied intermittent fasting, measured glycaemic control using HbA1c, the standard blood test that estimates average blood sugar over roughly two to three months. The time-restricted group recorded a drop of about 0.5 percentage points in HbA1c, outperforming the calorie-restriction group. The study also found no meaningful rise in dangerous highs or lows in blood sugar, or in diabetic ketoacidosis, a serious complication that can occur when insulin is too low.
The research matters because fasting-style approaches have been viewed cautiously in type 1 diabetes, where insulin must be matched carefully with food intake, exercise and other factors. While the study suggests the strategy may be a practical alternative to constant calorie counting for some patients, it did not show clear weight-loss benefits. That limits how broadly the results can be applied, especially since all participants had obesity and the sample was small.
Varady and her colleagues say the trial is best seen as an early signal rather than a green light for widespread use. The researchers and the journal report that larger, multi-centre studies will be needed to determine whether the approach works across more varied patients, whether benefits last, and how people can safely fit an eight-hour eating window into everyday life over the long term.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
