The moderating role of eating behaviour traits in the association between exposure to hot food takeaway outlets and body fatness

The obesogenic environment significantly contributes to the prevalence of overweight and obesity. One aspect is the easy access to hot food takeaway outlets, the prevalence of which has increased considerably. Previous research has shown a link between exposure to takeaway outlets and unhealthy dietary behaviors and higher body weight, although the evidence is inconclusive. This inconsistency might stem from neglecting individual psychological traits' interaction with food environments. Some individuals may be more susceptible to environmental food cues than others. Eating behaviour traits, such as those measured by the Three-Factor Eating Questionnaire (TFEQ-R18) – cognitive restraint, uncontrolled eating, and emotional eating – are stable characteristics influencing eating behavior. Higher uncontrolled and emotional eating scores have been linked to poorer diet quality and higher body weight, while the evidence for cognitive restraint is mixed. This study aimed to explore how these eating behaviour traits moderate the relationship between exposure to takeaway outlets and individual takeaway consumption and adiposity.

Studies examining the relationship between exposure to takeaway outlets and health outcomes have yielded mixed results. Some studies found a positive association between exposure to takeaway outlets and unhealthy dietary behaviour and greater body weight, while others found no significant association. The inconsistent findings might be due to a failure to consider how individual differences in psychological traits interact with food environments. Previous research has shown that some individuals are more susceptible to the influence of environmental cues, such as the presence of takeaway outlets, than others, depending on their psychological traits, particularly external eating. Eating behaviour traits, such as those measured by the TFEQ-R18 (cognitive restraint, uncontrolled eating, and emotional eating), have been linked to diet quality and body weight in previous studies, suggesting potential moderating roles in the relationship between food environment and health outcomes. However, few studies have directly investigated the interaction between these traits and food environment exposure.

This cross-sectional study utilized data from a subsample (n=4791) of the Fenland Study cohort in Cambridgeshire, UK. Takeaway outlet exposure was determined using participants' residential addresses and data from local authorities, categorized into quartiles based on the number of outlets within a 1-mile radius. Eating behaviour traits were assessed using the TFEQ-R18, measuring cognitive restraint, uncontrolled eating, and emotional eating. Primary outcomes included consumption of takeaway-like foods (from a food frequency questionnaire) and body fat percentage (measured using dual-energy X-ray absorptiometry, DEXA). Secondary outcomes were fat mass index (FMI) and BMI. Covariates included sex, age, education level, occupational social class, household income, and the number of supermarkets within a 1-mile radius. Multiple linear regression models were used to examine associations between takeaway outlet exposure, eating behaviour traits, and outcomes, adjusting for covariates. Effect modification was investigated using multiplicative interaction terms, with significance set at α=0.10 for interactions and α=0.05 for other analyses. Multivariate imputation by chained equations (MICE) was used to handle missing data.

The study included 4791 participants (mean age 51.0, 53.9% female). Higher exposure to takeaway outlets and higher eating behaviour trait scores were independently associated with greater takeaway consumption and body fat percentage. Uncontrolled eating did not moderate the associations between takeaway outlet exposure and either takeaway consumption or body fat percentage. However, cognitive restraint showed a moderating effect on the association between takeaway outlet exposure and takeaway consumption. The association was stronger for individuals with higher cognitive restraint scores. Emotional eating moderated the association between takeaway outlet exposure and body fat percentage, with the association being stronger for individuals with lower emotional eating scores. These moderating effects were relatively small. After adjusting for sociodemographic characteristics, participants in the highest two quartiles of takeaway outlet exposure consumed more takeaway foods and had a higher body fat percentage compared to those in the lowest quartile. Emotional eating and uncontrolled eating were positively associated with both takeaway consumption and body fat percentage, while cognitive restraint was negatively associated with takeaway consumption but positively associated with body fat percentage.

The findings align with previous studies showing a positive association between takeaway outlet exposure and unhealthy dietary habits and higher body weight. The observed moderating effects of cognitive restraint and emotional eating are noteworthy. The stronger association between takeaway outlet exposure and takeaway consumption among those with high cognitive restraint suggests that individuals actively trying to restrict their food intake may struggle more in environments with high takeaway outlet density. The stronger association between takeaway outlet exposure and body fat percentage among low emotional eaters suggests that the food environment's influence may be more pronounced for those less prone to emotional eating. These moderating effects, however, were relatively small, suggesting both individual and environmental factors are crucial in determining dietary habits and adiposity. The lack of moderating effect of uncontrolled eating is unexpected and deserves further investigation.

Both individual differences in eating behaviour traits and exposure to takeaway outlets were associated with increased takeaway consumption and adiposity. The evidence for increased susceptibility to takeaway outlets based on specific eating behaviour traits was weak, with the exception of small effects for cognitive restraint and emotional eating. This highlights the need for integrated strategies targeting both individual behaviour and the food environment to effectively combat obesity. Future research could explore other psychological factors and utilize longitudinal designs to better understand causal relationships.

The cross-sectional design limits causal inferences. The TFEQ-R18, while generally reliable and valid, may have limitations, particularly for emotional eating due to the limited number of items. The temporal mismatch between food outlet data (2011) and other data (2005-2015) could lead to misclassification. The sample might not be fully representative of the broader UK population, especially regarding ethnic diversity and age range (mostly older adults). The measure of takeaway consumption might have underestimated or overestimated actual intake due to the inclusion of some foods that are not exclusively from takeaways or the exclusion of some takeaway options.