Effect of a Mediterranean Dietary Pattern Providing Higher or Lower Carbohydrate Intake on Physical Performance and Biochemical Markers in Non-professional Athletes

Objectives: Mediterranean diet (MD) is a healthy diet with a favourable impact also on physical fitness. However, the impact of MD on physical performance was not adequately investigated and often dietary regimes with low carbohydrate intake are selected by subjects with high physical activity. The aim of the study is to evaluate the effect of MD providing different amounts of carbohydrates on physical performance in a group of non-professional sport athletes. Methods: Subjects engaged in both strength and endurance activities are enrolled to participate in a randomised, controlled, crossover study. Dietary interventions consist of a traditional MD characterized by 55-60% of daily energy derived from carbohydrates (HCMD) or a MD moderate in Carbohydrates (MCMD) with 40-45% of daily energy provided by carbohydrates. The protocol involves an acute and long-term evaluation and personalized recommendations. For the acute study, a higher carbohydrate versus lower carbohydrate meal is tested before the performance tests. For the long-term study, each intervention lasts 8-week and is separated by a 6-week washout period. Before and after the interventions, anthropometrics, body composition, haematochemical parameters, oxidative stress and inflammatory markers and physical performance are investigated. Results: While the study is still ongoing, thirteen subjects engaged in strength activity completed the whole intervention. ANOVA did not show a significant time x treatment interaction for the variables under study both in the acute and long-term protocol apart from elbow flexors Maximum Voluntary Contraction (MCV) and arm circumference. After 8-week intervention, considering intragroup data, a significant decrease overtime in strength (and arm circumference) was found following the MCMD (P< 0.05) while no differences after HCMD intervention. No significant changes were found in other muscles MCV and in the haematological profile. Conclusions: Overall, LCMD did not improve physical performance and other parameters with respect to HCMD. These results can contribute to promote awareness of the adequacy of a balanced MD in non-professional strength trained athletes. Funding Sources: The study was supported by Barilla G. e R. Fratelli S.p.a.