A 10-hour eating window showed a modest short-term effect on nighttime glucose levels in adults with prediabetes, but the benefit was not sustained at 3 months. In an exploratory analysis from the RESET randomized controlled trial published in Diabetes Research and Clinical Practice, time-restricted eating (TRE) did not improve fasting glucose or glycosylated hemoglobin (HbA1c) versus control.

The analysis included 46 adults with prediabetes assigned to either a 10-hour TRE intervention (n=20) or a control group (n=26). Changes in continuous glucose monitoring outcomes, fasting glucose, and HbA1c were evaluated at 6 weeks and 3 months using a linear mixed-effects model.

No between-group differences were identified for fasting glucose or HbA1c at either time point. Nighttime average sensor glucose was lower with TRE than control after 6 weeks by 0.3 mmol/L (95% CI, -0.6 to -0.1), but this difference was not maintained after 3 months at 0.1 mmol/L (95% CI, -0.4 to 0.2). Within the TRE group, the 24-hour and daytime coefficient of variation declined at 6 weeks, although these changes were not present at 3 months.

The analysis suggests that TRE may provide a small early improvement in nighttime glucose in adults with prediabetes, while larger and longer studies are needed to clarify durable metabolic effects.