We used a 35-item Yale Food Addiction scale 2.0 [13], a well-known food dependency assessment, to determine food addiction symptoms over 12 months ago. These symptoms include tolerance, reversal, overdose, persistent tendency or an unsuccessful attempt to reduce it, spending too much time or recycling, and continued use despite being aware of the consequences and activities due to abandoned materials. The scale also assesses clinical disorders or discomfort resulting from addictive eating habits. The YFAS 2.0 are an eight-point Likert scale that varies from “never” (= 0) to “every day.” (= 7). A question is considered positive if its score is equal to or higher than the threshold, depending on whether the point is higher or lower than that threshold. Cronbach’s alpha coefficient of 0.87 indicates an adequate internal coefficient [17].

The Depression, Anxiety, and Stress Scale-21 (DASS-21) was applied to assess the anxiety and stress scale. Lovibond and Lovibond developed the 21-item scale in 1995 to measure stress, anxiety, and depression. Each item’s scoring method rose from zero (it does not apply to me or never) to 3 (often applied to me). The sub-scales and related items were as follows: anxiety (items 2, 4, 7, 9, 15, 19, 20), stress (items 1, 6, 8, 11, 12, 14, 18), and depression (items 3, 5, 10, 13, 16, 17, 21). Brown, Chorpita, Korotitsch, and Barlow [18] also reported validity of 0.77 for the scale. Each component contained seven items, whose final score could be obtained by summing the items’ scores. Thus, the score could range between 0 and 21 per subscale. In Iran, the reliability of the DASS-21 has been reported at 0.82 via Cronbach’s alpha method [19].

It was designed and developed by Cepeda-Benito et al. [20] to measure adult food-trait cravings. This questionnaire contains 15 items. Answers were recorded on a Likert scale from one (never not applicable or not applicable) to six (always).

An ethical committee approved the study procedure of Ferdowsi University of Mashhad (IR/09/11/1398), and informed consent was obtained from the participants. All methods have been carried out under relevant guidelines and regulations.

This research was divided into two phases: the instrument's translation, its psychometric properties analysis, and its validity verification. The YFAS 2.0 was translated into Farsi (Persian) using the back-translation technique in the first phase. In this technique, one translation team translates the scale into Persian, and then the second team translates it back into the original language. The translation accuracy was judged by closely matching the second team’s original version. However, as Hambleton et al. [21] pointed out, this commonly used technique has shortcomings. They suggested that translators be proficient in both languages and familiar with both cultures. The quality of the translation has been assessed as to how it fits the initial text. Accordingly, two translators were contacted to help with the study. The translators worked independently, and no significant differences were found in the translation and expression of the items. The authors subsequently reached a consensus with the translators on both versions. Finally, some items were revised by a professor of English and other psychologists to make them more understandable and comprehensible to the target audience. Care was taken to ensure that the length of the items corresponded to the original scale. The authors then achieved agreements with the translators for the final version.

In the first stage, the outliers were checked by z—scores and box plots (values + 3 standard deviations from the mean indicate univariate outliers). A visual check, skewness, and Kurtosis values demonstrated normally distributed data (see Table 1). In the second place, descriptive statistics, including mean, Standard Deviation (SD), and range, were calculated for Yale Food Addiction Scale Version 2.0 (YFAS 2.0). Third, Confirmatory factorial analysis (CFA) for ordinal data was used to investigate the internal structure of the YFAS 2.0. Maximum Likelihood was used for the estimation method, and Fitness indexes were evaluated with a 90 percent confidence interval for Model fitness, including Root Mean Square Error of Approximation (RMSEA), Parsimony Normed Fit Index (PNFI), Comparative Fit Index (CFI), Incremental Fit Index (IFI), Relative Fit Index (RFI), Standardized Root Mean Square Residual (SRMR) and Normed Fit Index (NFI). For a good fit model, CFI, IFI, RFI, NFI should be greater than 0.90, AGFI greater than 0.80, PNFI greater than 0.50, RMSEA less than 0.08, and SRMR less than 0.09. Fourth, Cronbach’s alpha coefficient of the YFAS 2.0 was estimated. Furthermore, in fifth place, Pearson’s correlation between the YFAS 2.0 with FCQ-T-r’s subscales and DASS-21 was investigated to obtain evidence of validity with other variables. For the data analysis, the SPSS-26 and LISREL 8.8 statistical programs were used.

Preliminary tests, such as data loss analysis, discarded data, and normality of the data were performed before the CFA. Discarded data were assessed by the Mahalanobis distance square with a significance level of 0.001 in AMOS software, and no discarded pieces of data were identified. Skewness (0.154–0.181) and Kurtosis (0.35–2.15) were used to test the normality assumption of the items. The normality of the data is met when the values range between ± 2 for skewness and ± 3 for Kurtosis [22]; the results showed the normal distribution of the data.