Although this study has many strengths and contributes not only to extend the validity and reliability of MEQ, but also to better understand the construct of Mindful eating, which is still not well-known, ome limitations and types of bias may have affected the present results:
(a)This study used a convenience sample that was obtained from several clustering of participants. A potential selection bias in the recruitment of participants can not be excluded. In
addiction, estimates of association derived from such a complex sample may be less precise than that derived from a simple random sample.
(b)Despite the large sample size and the variety of specific subgroups, the whole sample cannot be considered representative of the broad educational and social diversity of the Italian population. In addition, although this study sample had a better male-female balance than the original study, female were still prevalent.
(c)The test-retest sample size could have been larger, although it was quite adequate from a statistical point of view. However, a total of 12 subjects withdrew at the second stage of test- retest, a relevant proportion (17%) in a relative small sample such as this (n = 60), and the reasons were not given.
(d)Bias from inaccurate measurement may have affected variables such as BMI, actual dietary practice and physical exercise, as they were self-reported; therefore, future studies should assess these variables more objectively.
(e)The cross-sectional nature of the study did not allow assessing mindful eating before and after a specific mindful eating intervention, and thus this might be the focus of future investigations.
5.5 CONCLUSION
Results from this study contribute to the empirical validation of the concept of mindful eating, supporting the use of the MEQ by clinicians and researchers to assess it in outcome research. These results would also add a better understanding of the interaction between BMI, diet, physical exercise and mindful eating, and would help choosing effective strategies for preventing or addressing overweight and obesity risk.
Chapther 6: STUDY 3
The roles of Mindfulness and Mindful eating as mediators and moderators between overeating and psychological distress
6.1 BACKGROUND
Recent reviews (O’ Really et al., 2014; Godfrey, et al., 2014; Godsey, 2013; Wander- Berghe et al., 2011; Katterman, et al., 2014) suggested a positive effect of mindfulness based interventions on disordered eating behaviours such as binge eating, emotional and external eating. However, many of the results of the discussed studies are limited due to the lack of a control group. Therefore, it is not clear whether or not mindfulness can be considered a causal factor in improving eating behaviours.
The associations between mindfulness and disordered eating behaviours have been explored in some studies both in clinical and non clinical populations. In student-based population studies, results showed positive association between mindfulness and eating pathology (Lavender, Lattimore, Fisher, & Malinowski, 2011; Lavender et al., 2009; Masuda, Price, Latzman, 2012). In women, dispositional mindfulness was found to be negatively associated with emotional and uncontrolled eating, but not with cognitive restraint. Ouwens et al. (2014) in a morbid obese sample, also found that independent of socio-demographics, BMI, and affective symptoms, dispositional mindfulness was negatively associated with emotional and external eating, and positively associated with restraint eating. Besides, in a study based on acollege students sample, mindfulness has been shown to moderate the association between disordered eating cognitions and disordered eating behaviors and under higher levels of mindfulness, the positive association between disordered eating cognitions and disordered eating symptoms is attenuated (Masuda, et al., 2012).
Moor, Masuda, Bradley, and Goodnight (2014) reported that body image flexibility moderates the association between disordered eating cognition and disordered eating behavior; for women with greater body image flexibility, disordered eating cognition was not positively associated with disordered eating behavior.
In another study, (Tylka, Russell & Neal, 2014) self-compassion (a component of mindfulness) buffered the links from media thinness-related pressure to disordered eating and thin-ideal internalization. Finally, mindfulness was found to be a partial moderator in reducing the disordered eating symptomatology in na intervention versus control group comparison (Bush, Rossy, Mintz & Schopp, 2014).
As reported in the literature (e.g., Baer et al, 2006; Brown & Ryan, 2003), in the association between mindfulness and eating behaviour patterns, psychological distress (anxious and depressive symptoms) have been found in relation to mindfulness and disordered eating behaviours, even though the direction of causality is still unclear. Another study (Coffey & Hartman, 2013) reported an inverse relationship between mindfulness and psychological distress.
Associations between affective states and eating behaviours have been found in women concerned with their weight (Ouwens et al., 2009) and in obese women with binge eating disorders (Schulz & Laessle, 2010). On the other hand, Owen et al. (2014), in a morbid obese sample, found that anxiety was associated only with emotional eating, but not with restrained or external eating, whereas depressive symptoms were not significantly associated with either of the eating behaviour styles.
Preliminary findings have also demonstrated that mindfulness and psychological flexibility moderate a variety of associations between harmful psychological factors and behavioral health outcomes (Andrew & Dulin 2007; Feltman et al.. 2009; Kashdan & Kane 2011; Kratz et al.. 2007; Saavedra et al.. 2010), so that a greater level of these variables attenuate the strenght of the association between psychological factors and outcomes. For instance, Masuda and Wendell (2010) found that mindfulness was inversely related to disordered eating cognitions and also to
general psychological ill-health and emotional distress in interpersonal contexts. Therefore, Mindfulness was found to partially mediate the relations between disordered eating-related cognitions and the two predicted variables.
Masuda and Latzman (2012) reported that, indipendently to demographic variables and BMI, both self-concealment and psychological flexibility were uniquely related to dieting. Only psychological flexibility was uniquely associated with bulimia/food preoccupation and none of them were uniquely associated with oral control. In addition, mindfulness was also reported to moderate the association between unavoidable distressing events and psychopathological symptoms/negative affect (Bergomi, Strole, Michalak, Funke, & Barking, 2013). Mindfulness and psychological flexibility resulted to be interrelated but not redundant constructs and they were negatively associated with somatization, depression, anxiety and general psychological distress (Masuda & Tully, 2011).
Lastly, mindfulness was negatively associated with neuroticism and positively associated with conscientiousness, while psychological inflexibility was the opposite. Further, conscientiousness evidenced the strongest contribution to mindfulness, and neuroticism to psychological inflexibility (Latzman & Masuda, 2013).
Taken as a whole, studies exploring the role of mindfulness as a mediator or moderator between different variables are only at an onset stage. Moreover, none of the previous studies has analyzed the potential role of mindfulness and mindful eating as mediators or moderators in the relationship between overeating behavior and psychological distress.
6.1.1 Objectives and hypothesis