Polish Adaptation and Validation of the Intuitive (IES-2) and Mindful (MES) Eating Scales-The Relationship of the Concepts with Healthy and Unhealthy Food Intake (a Cross-Sectional Study)

Intuitive (IE) and mindful (ME) eating share internally focused eating, yet previous studies have shown that these concepts are not strongly correlated, which suggests that they might be differently related to food intake. The study aimed to adapt the original Intuitive (IES-2) and Mindful (MES) Eating Scales to the Polish language, to test their psychometric parameters and, further, to examine associations of IE and ME with an intake of selected food groups, i.e., healthy foods (fresh and processed vegetables, fresh fruit) and unhealthy foods (sweets, salty snacks). A cross-sectional study was conducted in 2020 in a group of 1000 Polish adults (500 women and 500 men) aged 18-65 (mean age = 41.3 +/- 13.6 years). The factor structure was assessed with exploratory (EFA) and confirmatory (CFA) factor analysis as well as structural equation modeling (SEM). Measurement invariance across gender was assessed with multiple-group analysis. Internal consistency and discriminant validity of the two scales was tested. Spearman's correlation coefficient was used to examine the correlation between IES-2 and MES subscales with food intake. A 4-factor, 16-item structure was confirmed for IES-2, while EFA and CFA revealed a 3-factor, 17-item structure of MES. Both scales demonstrated adequate internal consistency and discriminant validity. Full metric and partial scalar invariance were found for IES-2, while MES proved partial invariances. "Awareness" (MES) and "Body-Food Choice Congruence" (IES-2) positively correlated with intake of healthy foods and negatively with the intake of unhealthy ones. "Eating For Physical Rather Than Emotional Reasons" (IES-2) and "Act with awareness" (MES) favored lower intake of unhealthy foods, whereas "Unconditional Permission to Eat" and "Reliance on Hunger and Satiety Cues" (IES-2) showed an inverse relationship. A greater score in "Acceptance" (MES) was conducive to lower intake of all foods except sweets. The results confirmed that adapted versions of the IES-2 and MES are valid and reliable measures to assess IE and ME among Polish adults. Different IE and ME domains may similarly explain intake of healthy and unhealthy foods, yet within a single eating style, individual domains might have the opposite effect. Future studies should confirm our findings with the inclusion of mediating factors, such as other eating styles, childhood experiences, dieting, etc.