The sample was recruited, for convenience, through social media between June and July 2023. Sample size calculation was conducted according to Pasquali’s recommendations [18]. It was considered to include 15 respondents per each of the 8 items that constitute ESEBS-BR, increasing by 20% for possible missing data. This resulted in a minimum size of 144 participants in order to get reliable results from the parametric tests. Data were collected from a total of 241 participants. However, 13 individuals who completed the questionnaires incorrectly or incompletely were excluded from the study, bringing to 228 participants finally included in the study and analysis.
Ethical procedures
The study was conducted in accordance with the Declaration of Helsinki and approved by the Research Ethics Committee of the Pontifical Catholic University (CAAE: 64659222.0.0000.5336). Participants were invited to voluntarily take part in the study without any form of compensation. They completed the forms and questionnaires only after confirming their understanding and agreeing to the Informed Consent Form
Stage 1 - Transcultural adaptation
The transcultural adaptation process followed the model proposed by Beaton et al. (2007) [19] consisting of six stages. It began with translation, where two translators fluent in Italian and with Portuguese as their native language, one specialized in the field and the other without knowledge of the theme, independently translated the original version into Portuguese, generating versions T1 and T2. The T1 and T2 versions were compared and synthesized by an impartial researcher, mediating discussions on translation differences resulting in a common translation (T-12). The T-12 version was back-translated into Italian by two translators, unaware of the tool's purpose, ensuring correspondence with the original version and generating versions RT1 and RT2.
Two committees were formed; the first unified all versions into a pre-final version in Portuguese, and the second, composed of specialists from different regions of Brazil, analyzed equivalences in four levels: semantic, idiomatic, experiential/cultural, and conceptual. The scale was pre-tested on a sample of 30 participants, following Beaton et al.'s (2007) [19] recommendations. Participants responded to sociodemographic questionnaires and the pre-final version of the ESEBS-BR, providing feedback on clarity and understanding of the items.
All produced documents were reviewed by the responsible researchers, and the adapted version was sent to the original authors for approval. The analysis of content validity was based on experts' responses regarding semantic, idiomatic, experiential, and conceptual equivalences. The content validity index (CVI) was calculated based on a minimum agreement of 0.80 among judges, verifying the scale's validity [20,21].
Stage 2 - ESEBS-BR Validation and Psychometric Analyses Questionnaires
Participants completed the questionnaires online on the QualtricsXM platform. The survey included the transcultural version of ESEBS adapted for Brazilian Portuguese (ESEBS-BR), other validated measures of eating behavior, and sociodemographic and anthropometric information. The following instruments were used for this stage:
(a) Sociodemographic and anthropometric data: A brief survey was created specifically for this research and contained questions on age, gender, weight, height, education level, marital status, living situation and monthly family income. BMI was calculated as follows: weight in kilograms (kg) divided by height in meters (m) squared (kg/m2).
(b) ESEBS-BR, 8 items, Brazilian version: This tool is a self-report scale consisting of 8 items that aim to measure how easy it would be to resist the urge to eat in two different situations on a 6-point Likert response scale ranging from 0 “not easy at all” to 5 “completely easy” [17]. The original version of the scale consists of two subscales, namely social and emotional: the former measures the ability to regulate eating in social contexts (e.g., "How easy would it be for you to resist the urge to eat when eating out with friends"), and the latter, the ability to resist in situations of emotional activation (e.g., "How easy would it be for you to resist the urge to eat when you are worried about work/study reasons”). Cronbach’s alphas from the original study revealed good reliabilities, namely being 0.820 for the Emotional scale and 0.786 for the Social scale.
(c) Binge Eating Scale (BES): In this tool participants are required to choose, for each item, the statement that most accurately reflects their response. Each statement is associated with a score ranging from 0 to 3, covering the spectrum from absence ('0') to maximum severity ('3') of the BED. The cumulative score is determined by summing the points assigned to each item [22,23]. Following the instructions given by Marcus et al. (1985) [24], individuals are categorized based on the following scores: those with a score equal to or less than 17 are considered without BED; those with scores between 18 and 26 are classified as having moderate BED; and those with a score equal to or greater than 27 are identified as having severe BED. In the present study, Cronbach's alpha was 0.89.
(d) The Three Factor Eating Questionnaire (TFEQ-21): To determine the degrees of cognitive restriction, emotional eating and lack of eating control, the classification instructions provided by the team that developed the questionnaire [25] were used. A 4-point response format was used for items 1 to 20, and an 8-point numerical rating scale was used for question 21 [25]. The Cronbach's statistics in our sample were for the Emotional scale 0.93, Cognitive Restriction 0.75, and Lack of Control 0.84.
Data analyses
Data were analysed with JASP version 0.14.1.0.
To assess the normality of the distribution, skewness and kurtosis values were considered, accepting a distribution with skewness and kurtosis lower than the absolute value of 1 as normal [26].
A Confirmatory Factor Analysis (CFA) was performed to test the internal structure of the ESEBS-BR. In accordance with the original study [17], a model with two correlated factors was tested. The model fit was evaluated using the ML Chi-square test statistic, Comparative Fit Index (CFI), Tucker Lewis Index (TLI), Standardized Root Mean Square Residual (SRMR), and Root Mean Square Error of Approximation (RMSEA). By convention, a CFI and TLI > 0.900 indicate an adequate model fit, and a CFI and TLI>0.950 indicate a good fit. An SRMR < 0.08 is considered a good fit. RMSEA values < 0.050 represent a close fit, while values between 0.050 and 0.080 represent a reasonably close fit, and values > 0.080 represent an unacceptable fit [27]. Reliability was measured by applying Cronbach's alpha and McDonald's omega tests with 95% confidence intervals. Values are considered adequate when ≥0.70 [28] Pearson’s correlation test was used to assess the convergent validity between ESEBS-BR, TFEQ and BES..
Six subgroups were formed based on participants’ BMI using WHO norms: underweight participants, BMI<18.5; normal weight participants, BMI between 18.5 and 24.9 kg/m²; participants with overweight, BMI between 25.0 and 29.9 kg/m²; participants with first class obesity, BMI between 30.0 and 34.9 kg/m²; second class obesity, BMI between 35.0 and 39.9 kg/m²; and third class obesity BMI >40.0 kg/m². Emotional and social ESEBS scale scores were used to compare groups through a one-way analysis of variance (ANOVA). The results were interpreted with a 95% confidence interval.