## 4 Consumers' Behavior, Market Opportunities and Trends  
Two of the major 21 st century food policy challenges are the reduction of diet-related diseases and the improvement of environmental sustainability. Mediterranean dietary ingredients contain more energy, fiber, and nutrients per liter of water used; therefore, a shift towards the MD could reduce the consumptive water footprint by about 750 L/capita/day [225]. Consumers' perceptions about sustainability and food consumption has a highly significant effect on attitudes and personal and social norms related to waste reduction [226]. The most important drivers of food consumption are price, taste, convenience, and social and cultural factors and habits, in addition to the ethical aspects related to food [227]. The MD, as a plant-oriented dietary approach, appears to be an appropriate choice for humans and environmental sustainability because it reduces the environmental impact associated with the food value chain [228]. Moreover, the trend of decreasing adherence to the MD necessitates cross-disciplinary studies regarding its environmental, socioeconomic, cultural, and sustainability aspects, to preserve and transfer this sustainable dietary pattern to the next generations [229]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of Study** & **Country** & **No. of People** & **Health Effects** & **Reference** \\ \hline Observational study & - & - & Menopausal diseases & [195] \\ Observational study & Chile & 4348 & Chronic disease risk & [196] \\ Meta-analysis & - & - & Metabolic syndrome & [197] \\ Cohort study & Spain & 9408 men & Hypertension & [198] \\ Cohort study & Italy & 13,597 & Hypertension & [199] \\ Meta-analysis & - & 7000 & Hypertension & [200] \\ Randomized control & - & 296 & Atherosclerosis & [201] \\ analysis (RCA) & Spain & 187 & Atherosclerosis & [202] \\ RCA & 10 European & 373,803 & Obesity & [203] \\ Cohort study & countries & 15,798 & Type 2 diabetes & [204] \\ Cohort study & - & - & Breast cancer & [205] \\ Cohort study & United States & 51,529 & Prostate cancer & [206] \\ Population study & Greece & 22,043 & Mortality & [207] \\ Cohort study & - & 51,529 & Cognitive decline & [208] \\ Cohort study & United Kingdom & 74,886 & Stroke & [209] \\ RCA & 5 European & 1294 & Osteoporosis & [210] \\ \multirow{2}{*}{Observational studies} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{Depression} & \multirow{2}{*}{[211]} \\  & & & & \\ \multirow{2}{*}{Cohort study} & \multirow{2}{*}{Spain} & \multirow{2}{*}{22,786} & Obesity, cardiovascular & \\  & & & & disease, type 2 diabetes & [212] \\ Observational study & Greece & 1,865 & Dementia & [213] \\ Observational study & Italy & 480 & Osteoporosis & [214] \\ RCA & Spain & 288 & Cardiovascular events & [215] \\ Meta-analysis & - & 72 studies & Degenerative diseases & [216] \\ Longitudinal study & - & 3,316,633 & Kidney stones & [217] \\ Randomized control trial & Iran & 40 & Parkinson’s disease & [155] \\ Cross-sectional analysis & Germany & 340 & Cognitive performance & [218] \\ Cross-sectional analysis & United Kingdom & 511 & Cognitive function & [219] \\ Systematic review and & - & 41,963 & Cognitive function & [200] \\ meta-analysis & - & 34,168 & Cognitive function & [221] \\ Cohort study & Italy & 1936 & Sleep behavior & [222] \\ Cohort study & Italy & 185 & Sleep behavior & [223] \\ Cohort study & Italy & 1596 & Sleep behavior & [224] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Representation of different types of studies involving humans, in which positive effects of the consumption of the Mediterranean diet were found. Some references focus on various published studies and thus the number of people and countries where the study was carried out are not stated. The MD may represent an ideal example of a sustainable diet and a part of a sustainability-oriented lifestyle; however, its adherence is significantly affected by consumers' income and education, and other socio-economic drivers [225].