This research was planned and conducted as a descriptive research study in order to determine the effect of mood states during the COVID-19 pandemic process on eating behavior disorders and Mediterranean diet adherence in individuals and the relationship between these factors. The sample of the study consisted of individuals between the ages of 18-65 living in Turkey. This study was conducted on a total of 491(190 male, 301 female) individuals. The study data were obtained online through a form including questions about the sociodemographic information of individuals, Mediterranean Diet Adherence Scale (MEDAS), COVID-19 Fear Scale (FCV-19S), Three-Factor Eating Scale (TFEQ-R21), and nutritional habits The data obtained as a result of the study were evaluated with the Statistical Package for the Social Sciences (SPSS) 25.0 package program in the Windows environment and p<0.05 was considered significant in all calculations. A statistically significant correlation was found between the participants' FCV-19S and MEDAS and TFEQ-R21 (p<0.05). A significant correlation was found between the participants' TFEQ-R21 sub-dimension cognitive restriction and MEDAS and FCV-19S (p<0.05). A significant correlation was found between the participants' TFEQ-R21 subdimension emotional eating and FCV-19S (p<0.05). A significant inverse relationship was found between the participants' TFEQ-R21 sub-dimension, uncontrolled eating, and MEDAS (p<0.05). A significant correlation was found between the participants' TFEQ-R21 sub-dimension, uncontrolled eating, and FCV-19S (p<0.05). As a result, it was found that increased fear of COVID-19 in adults increased TFEQ-R21 total score, emotional eating, cognitive restriction and uncontrolled eating behavior levels, increased uncontrolled eating decreased MEDAS compliance, and increased cognitive restriction tended to increase MEDAS compliance. Increased FCV-19S was found to be associated with increased MEDAS. It is thought that interdisciplinary studies will be beneficial to reduce the level of fear felt by adults during the pandemic and to increase MEDAS levels by positively affecting their eating behaviors.