Purpose. To investigate a cohort of young Italian nurses to identify whether the body mass index (BMI) and eating flexibility differed and were associated according to the basic characteristics of sex, smoking behavior, or shift activity, the levels of neutrophils, lymphocytes, or platelets in blood, and the psychological conditions of anxiety, depression, stress, or insomnia. Materials and Methods. The data include sex, BMI, smoking behavior, shift activity, neutrophil, lymphocyte, and platelet levels, eating flexibility [measured using the eating disorder flexibility index (EDFLIX) and the subdimensions EDFLIX-GF for general flexibility, EDFLIX-FoEx for food and exercise flexibility, and EDFLIX-WeSh for weight and shape flexibility], and mental health [assessed using the depression, anxiety, and stress scale (DASS-21) and the insomnia severity index (ISI)]. Results. Differences in BMI with shift work (P=0.042) and anxiety with total EDFLIX (P<0.001), EDFLIX-GF (P<0.001), and EDFLIX-WeSh (P=0.044) scores were significant. Having depression was associated with significant differences in total EDFLIX (P<0.001), EDFLIX-GF (P=0.005), and EDFLIX-WeSh (P<0.001) scores. Nurses with moderate stress reported high total EDFLIX (P<0.001), EDGLIX-FoEx (P<0.001), and EDFLIX-WeSh (P=0.013) scores. Nurses with mild stress reported high EDFLIX-GF scores (P<0.001). Nurses without insomnia symptoms reported significantly high EDFLIX- FoEx scores (P<0.001). Associations between lymphocyte levels and EDFLIX-FoEx (β=-0.264; P=0.003), stress and EDFLIX-total (β=-0.436; P<0.001), EDFLIX-GF (β=-0.466; P<0.001) and EDFLIX-WeSh (P=0.022), and also between insomnia and EDFLIX-FoEx (β=-0.245; P<0.001) were significant. Conclusions. Nurses, from the beginning of their careers, should be monitored and encouraged to avoid adverse health practices that negatively influence their quality of life.