• carbohydrate
• diabetes
• diet
• nutrition

Early time-restricted feeding (eTRF) is a form of intermittent fasting that involves restricting food consumption early in the day to align with the circadian rhythm and promote ketosis. We hypothesized that restricting carbohydrate-rich food in the morning may provide the same cardiometabolic benefits of eTRF while not requiring an absolute daily fast of 16-18 hours, which is often unfeasible and poorly accepted. In this proof-of-concept study, we examined the efficacy of early time-restricted carbohydrate consumption (eTRC) on weight loss, glucose homeostasis, and beta-cell function in subjects with type 2 diabetes (T2D).
In this parallel-arm, randomized clinical trial, 27 patients with T2D were randomized to a 12-week eTCR diet or a Mediterranean-style control diet with matched calorie restriction and macronutrient distribution. Body composition, continuous glucose monitoring (CGM), and food diary analysis were performed every 4 weeks. Mixed meal tests (MMT) and routine biochemical analyses were performed at baseline and at 12 weeks.
12 patients in the eTCR arm and 11 patients in the control arm completed the study. The two groups experienced significant and comparable reductions in body weight, fat mass, fasting plasma glucose, and HbA1c , as well as similar improvements in free-living glucose excursions assessed by CGM and MMT-derived glucose tolerance, insulin resistance.
Furthermore, the two study groups experienced similar improvements in triglyceride levels, alanine transaminase (ALT), and gamma-glutamyl transferase (GGT), and numerical reductions in LDL cholesterol and TSH, without significant changes in HDL cholesterol, systolic and diastolic blood pressure, heart rate, creatinine, urea, uric acid, aspartate transaminase (AST), and erythrocyte sedimentation rate. Diet-induced changes in body weight and cardiometabolic parameters were not related to the self-reported percent carbohydrate intake after lunch.
The proposed eTRC diet provides a feasible and effective option for weight loss and glucose control in patients with T2D, without additional metabolic benefits compared with a standard-of-care dietary regimen.