The impact of intermittent fasting and Mediterranean diet on older adults' physical health and quality of life: A randomized clinical trial.

Background and aims: Non-communicable chronic diseases are on the rise globally, and diet plays a crucial role. Intermittent fasting (IF), particularly time-restricted eating (TRE), has emerged as a potential strategy to manage these conditions. Research suggests that TRE, combined with healthy diets like the Mediterranean diet, may benefit populations, including older adults.

Methods and results: Seventeen adults over 60 years of age were randomly assigned to the TRE + MED group (n = 8), following a 12-h fast with the Mediterranean diet, or the MED-DIET group (n = 9), following the diet without fasting. Over three months, changes in anthropometric, biochemical, and quality of life measures were assessed. The TRE + MED group showed significant reductions in BMI (p = 0.040), waist circumference (p < 0.001), hip circumference (p = 0.025), waist-to-hip ratio (p = 0.023), and systolic blood pressure (SBP) (p = 0.020), along with changes in fasting glucose. In the MED-DIET group, only SBP decreased significantly (p = 0.022). Between-group comparisons showed greater improvements in waist circumference (p = 0.001) and waist-to-hip ratio (WHR; p = 0.036) in the TRE + MED group. Conversely, gamma-glutamyl transferase (GGT) levels improved more in the MED-DIET group (p = 0.020). However, in the between-group comparison, only the reduction in waist circumference, WHR, and GGT levels reached statistical significance. Both groups improved Mediterranean diet adherence, quality of life, and stool regularity, but only 20 % of the TRE + MED group was willing to continue fasting, compared to 100 % in the MED-DIET group.

Conclusion: TRE combined with the Mediterranean diet offers superior health benefits compared to the Mediterranean diet alone. In addition, adhering to a consistent meal schedule and regulating meal timing appear to be more challenging for the studied population.