Validation of the Yale Food Addiction Scale 2.0 and estimation of the population prevalence of food addiction.

BACKGROUND & AIMS: Food addiction (FA) is likely to contribute to the global obesity epidemic. Most studies of FA have been conducted within clinical and/or highly selected populations, suggesting that prevalence estimates of FA may be biased. This is problematic as valid estimates of the population prevalence of FA is a requirement for informing and designing public health initiatives focusing on this phenotype. Therefore, we aimed to estimate the weighted prevalence of food addiction in the adult general population of Denmark.

METHODS

A random sample of 5000 individuals aged 18 to 62 from the Danish population was invited to participate in a survey, which included the Yale Food Addiction Scale (YFAS 2.0) and several rating scales measuring eating pathology and other psychopathology. Health, demographic and socioeconomic data from the Danish registers were linked to all invitees to allow for attrition analysis. The analysis had three steps: I) Psychometric validation of the Danish version of YFAS 2.0 II) Attrition analysis to examine selection bias, and III) Estimation of the weighted prevalence of FA taking attrition into account.

RESULTS

The confirmatory factor analysis of the YFAS 2.0 supported a one-factor model, and the scale had good internal consistency. The YFAS 2.0 score correlated with eating pathology including binge eating frequency, impulsivity and body mass index (BMI). The survey response rate was 34.0% (n = 1699) with a slight overrepresentation of respondents with higher socioeconomic status. The crude prevalence of FA was 9.0%. When taking attrition into account, the weighted prevalence of FA was 9.4% CI 95% [7.9-10.9].

CONCLUSIONS

The psychometric properties of the Danish version of the YFAS 2.0 were good. The weighted prevalence of FA was very similar to the crude prevalence estimate. This suggests that attrition may not be a large problem when estimating the prevalence of FA with the YFAS 2.0.