## 4 Discussion  
According to our current knowledge, this is the first study in which body composition changes were monitored over a period of about 8 months including the pre-season sport training session, the entire competitive championship, as well as the play-off in 11 athletes of the volleyball team. It is worth underlining that all players had an optimal adherence to the MD, which was maintained over the entire study period, likely contributing to the improvement in their body composition. These findings are in accordance with previous studies in which a personalized Mediterranean dietary plan that included monthly changes and adjustments in elite athletes lead to optimal eating habits and health status [26, 27]. Conversely, [PERSON] et al. [6] showed that the adult population had an average adherence to the MD in the same Mediterranean area, thus underlining that the general population is less compliant to the MD pattern compared to elite athletes. However, regarding the assessment on the MD adherence among professional athletes, data are different especially if the attention is focused on the differences between female and male athletes, as well as if different types of sports are compared. Moreover, adherence to the MD is not always correlated with body composition and, consequently, to athletic performance [28, 29]. [PERSON] et al. [30] in a cross-sectional study indicated that monitoring the body composition and the adherence to the MD could help to optimize the sports performance of professional players. [PERSON] et al. [31] showed that appropriate nutrition is essential for athletes, and diet should be adequate in both quality and quantity to avoid deficiencies, limit fatigue, and replenish energy reserves, as well as to store energy substrates useful for power muscle contraction, particularly for elite athletes. Furthermore, the MD potentially assures an optimal supply of antioxidants, such as tocopherols, carotenoids, and polyphenols [32] that improve antioxidant defense and counteract oxidative stress induced by intense and prolonged physical exercise [33]. Therefore, providing athletes with a nutritional education about the beneficial effects of MD, along with a training plan and the monitoring body composition and hydration status may be a useful strategy to improve athletes' health and physical performance. In our volleyball athletes, with optimal adherence to the MD, we obtained an improvement of body composition parameters that were correlated to their performance. This suggested that the MD model could be properly considered a healthy dietary pattern in sport nutrition. The positive correlation between physical activity and the MD [34] could explain how athletes would strive towards this dietary model to improve both health and sport results [35]. According to data from the studies [36, 37], we recommended the combination of training programs other than with a specific dietary protocol, also with the conscious use of supplements, which allowed the athletes to improve the bioelectrical and body composition parameters over the entire competitive season. Our data revealed that lean mass was preserved and increased in all volleyball players, emphasizing, along with physical activity, the role of adequate nutritional intake to improve recovery, ameliorate muscle damage, and maintain muscle mass, as previously reported [38]. Importantly, measuring and monitoring body composition through the BIVA provides essential information on the needs of volleyball players over the entire championship. The generation of BIVA reference data for male competitive volleyball athletes allows differentiation of the athletic population from the general healthy population. Using the tolerance ellipses for volleyball players provided by [PERSON] et al. [25], we showed that our sample fits perfectly with the volleyball population.