The Mediterranean diet, but not time-restricted eating, mediates the effects of nesfatin on beta cell function among overweight, metabolically healthy individuals.

Nesfatin concentrations are positively correlated with beta cell function. However, it is unclear whether diet composition mediates this relationship. We recruited 27 overweight individuals who practiced Orthodox fasting (OF), a subset of the Mediterranean diet (MedDiet), for 7 weeks. Fourteen overweight people who practiced 16:8 time-restricted eating served as control group. Anthropometric parameters, biochemical data and adipokine levels were evaluated at baseline and after the end of the diet period (7 weeks from baseline). Subsequently, participants were asked to return to their usual eating plans, and an additional evaluation was performed 5 weeks after the end of the research diets (12 weeks from baseline). We observed a significant and negative correlation between HOMA-B and nesfatin values at 12 weeks, only in the OF group ( r = -0.455, p  = 0.01). In conclusion, returning to normal eating habits after 7 weeks of strict adherence to MedDiet affects the homeostatic balance between insulin secretion and nesfatin.