## 1 Introduction  
A healthy lifestyle can be defined as complex behavior patterns and routines that include healthy practices and exclude harmful habits. Healthy practices imply balanced nutrition and high consumption of fruits and vegetables, regular physical exercises and activities [1], rest, and restful sleep [2]. On the contrary, harmful habits involve poor eating [3], physical inactivity and sedentary behavior [4], sleep deficiency and deprivation [5], alcohol consumption [6], excessive smartphone use [7], and active, passive, and electronic smoking [8]. A healthy lifestyle has been associated with increased life expectancy [9], mental health [10], and psychological well-being [11], as well as beneficial effects on the hormonal [12], immune [13], and hematopoietic systems [14].  
Many people went through significant transformations in their healthy lifestyles throughout COVID-19. At the beginning of the pandemic, the average number of steps dropped from 10,000 to 4600 steps per day, sleep increased by 25-30 min per night, social time increased by more than half to less than 30 min, and screen time increased by more than double to more than 5 h per day [15]. Previous studies revealed unfavorable immediate and long-term impacts of the pandemic on self-reported physical activities and sedentary behaviors among people [16], including changes in eating habits [17], increased substance use [18], and problematic smartphone use [19]. These led to subsequent weight gain in more than a third of the people surveyed in France [20], Italy [21], Poland [22], UAE [23], and many other countries.  
Importantly, individuals with unhealthy lifestyle patterns have been reported to have more severe forms of COVID-19 [24]. The mechanisms that underpin these relations are not fully understood. They may include the activation of the immune and stress systems, as well as the detrimental influence of obesity on the course of the disease [11; 25; 26]. Unhealthy lifestyles can also lead to reduced immunity and organ injury, predisposing people to diseases, and their severity, commonly defined as 'communicable' such as SARS-CoV-2 [27].  
Lifestyle changes during lockdown occurred in both unfavorable and favorable directions. According to the results of the French NutriNet-Sante cohort study, 19.8% of the participants reported positive changes, such as increased consumption of fruits, vegetables, and fish [20], while increased physical activity, especially for bodyweight training, was reported by 38.3% of respondents from Italy [21]. In children and adolescents, the adverse effects of SARS-CoV-2 include an unbalanced diet with an increased risk of overweight or nutritional deficiencies, a sedentary lifestyle, lack of schooling, social isolation, and deteriorating mental health [28].  
Although a healthy lifestyle was critical during the COVID-19 pandemic, personality risk factors have not yet been investigated. In pre-pandemic studies, personality traits have been associated with health [29; 30; 31]. Physical activity and a vegetable diet were associated with increased extraversion, adherence to the Mediterranean diet, and lower alcohol and cigarette intake, and excessive use of screens and social networking sites was associated with greater conscientiousness. Lower fruit consumption, sleep issues, alcohol and tobacco consumption, smartphone use, and excessive use of the internet were all associated with increased neuroticism. Likewise, according to [PERSON] et al. (2021), greater perceived vulnerability, feeling stressed, apprehensive, and helpless during the pandemic was associated with more reports of positive lifestyle changes, including increased social/family support, increased awareness of mental health, and a positive lifestyle [32].  
Given the above, this study aimed to examine possible associations of the Big Five traits with a healthy lifestyle during the COVID-19 pandemic.