Effect of Time-Restricted Eating Versus Daily Calorie Restriction on Mood and Quality of Life in Adults with Type 2 Diabetes

Background/Objectives: This secondary analysis aimed to compare the effects of time-restricted eating (TRE) versus calorie restriction (CR) and controls on mood and quality of life in adults with type 2 diabetes (T2D). Methods: Adults with T2D (n = 69) were randomly assigned to one of three interventions for 6 months: 8 h TRE (eating only between 12 and 8 pm daily); CR (25% energy restriction daily); or a no-intervention control group. At baseline and 6 months, mood was assessed using the Beck Depression Inventory-II (BDI-II) and the Profile of Mood States (POMS) questionnaires, while quality of life was assessed using the Rand 36-Item Short Form (SF-36). Results: Body weight significantly decreased in the TRE group (−3.38%; 95% CI, −6.04 to −0.71%, p = 0.008), but not in the CR group (−1.80%, 95% CI, −4.50 to 0.91%, p = 0.32) versus controls by month 6. Fat mass, lean mass, and visceral fat mass remained unchanged in TRE and CR groups, versus controls, from baseline to month 6. No changes were observed in depression scores (BDI-II), total mood disturbance, or any POMS subscales (tension, depression, anger, fatigue, confusion, or vigor) in either the TRE or CR groups compared to controls. Similarly, there were no significant changes in the quality-of-life SF-36 constructs of vitality, bodily pain, mental health, and general physical health in the TRE or CR group versus controls. By month 6, there were no associations between changes in body weight, quality of life, and mood outcomes in any group. Conclusions: In conclusion, our findings suggest that TRE and CR do not have any effect on mood or quality of life in adults with T2D, relative to controls. However, the participants’ baseline mood and quality of life were generally within healthy ranges, and only minimal weight loss was achieved (3.5%, TRE only), which may explain the lack of observed effects.