Psychological Flexibility and Mindfulness Explain Intuitive Eating in Overweight Adults

Introduction

In the field of psychology, the study of eating behaviors and weight management largely has been a pathology-focused endeavor because it has explored and identified correlates and predictors of disordered rather than adaptive eating. As a result, the study of eating behaviors is disjointed, and much remains unknown about positive eating behaviors. It could be useful to understand more of adaptive eating behaviors and how they could be promoted in individuals with weight concerns in an obesogenic environment. One adaptive form of eating that has recently gained recognition is “intuitive eating,” defined as a style of eating that focuses on eating motivated by physical reasons, with an individual relying on his or her connection with and understanding of the body’s physical hunger and satiety cues rather than on emotional or environmental motivators (Avalos & Tylka, 2006; Tylka, 2006). Three central and interrelated components of intuitive eating have been identified: (a) unconditional permission to eat when hungry and what food is desired (i.e., lack of restriction in eating), (b) eating for physical rather than emotional reasons, and (c) reliance on internal hunger and satiety cues to determine when and how much to eat (Tylka, 2006).

Each of these three intuitive eating components has been found to be inversely related to eating disorder symptomatology and positively to physical and psychological well-being (Tylka, 2006). For example, intuitive eaters have been found to show greater unconditional self-regard and body satisfaction, as well as lower levels of both depression and disordered eating behavior (Bacon & Aphramor, 2011; Bacon, Stern, Van Loan, & Keim, 2005; Polivy & Herman, 1992; Smith & Hawks, 2006; Tylka, 2006; Tylka & Wilcox, 2006). Intuitive eating is associated with several markers of improved physiological health, including lower body mass index (BMI), cholesterol, and blood pressure, indicating lower cardiovascular risk (Augustus-Horvath & Tylka, 2011; Bacon & Aphramor, 2011; Bacon et al., 2005; Hawks, Madanat, Hawks, & Harris, 2005; Madden, Leong, Gray, & Horwath, 2012; Smith & Hawks, 2006; Tylka, 2006; Tylka & Wilcox, 2006). Despite the promising growth of research on this construct, research has been mainly conducted with normal weight samples (Avalos & Tylka, 2006; Denny, Loth, Eisenberg, & Neumark-Sztainer, 2013; Hawks et al., 2005; Smith & Hawks, 2006; Tylka, 2006) and only few studies have attempted to explain processes creating this adaptive eating behavior. It is important to study intuitive eating also in individuals with weight concerns and try to understand processes creating this adaptive eating behavior to examine its usefulness in weight loss and maintenance. Avalos and Tylka’s (2006) original acceptance model highlighted the significance of perceiving unconditional acceptance of one’s self and one’s body by external others for promoting an intuitive eating style. In comparison with this more interpersonal conceptualization of acceptance, Schoenefeld and Webb (2013) suggested that a self-compassionate orientation may help foster acceptance of internal unwanted events that would facilitate greater engagement in this adaptive eating style. Adopting a self-compassionate stance toward difficult internal experiences related to one’s body was related to eating more intuitively (Schoenefeld & Webb, 2013). Besides, psychological flexibility related to one’s body image (body image acceptance and action) accounted for a strong positive link between self-compassion and intuitive eating (Schoenefeld & Webb, 2013). Schoenefeld and Webb (2013) further suggested that intuitive eating could be viewed as acting in accordance with one’s values in the specific domain of food consumption even amid experiencing negative thoughts and feelings about one’s physical form.

Accordingly, the current study sought to provide a complementary perspective on the role of acceptance and flexibility in the context of this adaptive eating behavior by evaluating the role of mindfulness and psychological flexibility in intuitive eating. Psychological flexibility and mindfulness are often conceptualized as two related, yet distinct, adaptive regulation and coping processes that can be seen as opposites to experiential avoidance (Kashdan & Rottenberg, 2010). Psychological flexibility is defined as the ability to focus on the present moment and, depending on what the situation affords, to persist with or change one’s behavior in the pursuit of goals and values (Hayes, Luoma, Bond, Masuda, & Lillis, 2006; Hayes, Strosahl, & Wilson, 1999). It can be theorized as an overarching regulation process of experiencing whatever one is experiencing non-judgmentally, without defense or judgment (i.e., mindfulness), while engaging in value-directed activities (i.e., commitment to actions). Mindfulness, although its definition varies across researchers, can be construed as an adaptive regulation process of enhanced attention to and non-judgmental awareness of present-moment experiences (Brown & Ryan, 2003; Chambers, Gullone, & Allen, 2009). Although mindfulness can be cultivated through meditation and behavioral skill training (for a review, see Keng, Smoski, & Robins, 2011), mindfulness has also been conceptualized as a trait-like or dispositional characteristic that varies naturally in the general population, even without mindfulness training (Brown & Ryan, 2003). Baer, Smith, Hopkins, Krietemeyer, and Toney (2006) presented evidence that trait mindfulness has five facets: (a) non-reactivity (perceiving thoughts/feelings without reacting), (b) observing (paying attention to internal and external sensations), (c) acting with awareness (staying focused on present-moment experience and acting deliberately), (d) describing (describing/labeling thoughts/feelings with words), and (e) non-judging (accepting thoughts/feelings without evaluating them).

Mindfulness promotes the willingness to approach and experience emotions and is therefore likely to reduce avoidance-based coping, such as emotional eating (Cochrane, Brewerton, Wilson, & Hodges, 1992). Practicing mindfulness has been suggested to help individuals to “connect” with their inner experiences (such as hunger), thereby attenuating sensitivity to external or emotional cues to eat (Kristeller & Wolever, 2011). This is supported by results showing that mindfulness intervention diminishes both emotional and external eating (Alberts, Thewissen, & Raes, 2012). It has been proposed that, on a cognitive level, mindfulness reduces identifying with thoughts about food, body, and shape, thereby interrupting dysfunctional thinking patterns (Albers, 2011) that could predispose someone to emotional or restricted eating. People who are high in dispositional mindfulness tend to observe their thoughts and feelings without reacting to them in maladaptive ways and therefore are more able to behave constructively even when unpleasant thoughts and feelings are present (Hayes et al., 1999).

To this day, only a relatively small number of studies have addressed the meaning and effectiveness of mindfulness and psychological flexibility in the domain of eating behavior. So far, the findings are promising and suggest an inverse relationship between mindfulness and disordered eating behavior. Practicing mindfulness has been found to reduce body mass in overweight adults (Tapper et al., 2009) and food cravings (Alberts, Mulkens, Smeets, & Thewissen, 2010; Alberts et al., 2012; Forman et al., 2007), dichotomous thinking, body image concern, emotional eating, external eating (Alberts et al., 2012), and binge eating (Kristeller & Hallett, 1999). Moreover, higher levels of mindfulness seem to be negatively associated with disordered eating-related cognitions (Masuda & Wendell, 2010), and mindfulness has been found to partially mediate the link between disordered eating-related cognitions and psychological distress (Masuda, Price, Anderson, & Wendell, 2010; Masuda & Wendell, 2010) as well as moderating the association between disordered eating cognitions and disordered eating behaviors (Masuda, Price, & Latzman, 2012). However, different facets of mindfulness may be differently associated with eating behaviors. Whereas most subscales have been inversely related to psychological symptoms, observing has also found to predict more symptoms (Baer et al., 2006; Lavender, Gratz, & Tull, 2011). Lattimore, Fisher, and Malinowski (2011) found that observing was positively associated to uncontrolled eating and cognitive restraint of eating (Lattimore et al., 2011). Adams et al. (2012) found that describing and non-judging predicted lower symptoms of bulimia nervosa and lower body dissatisfaction, and acting with awareness was positively related to lower symptoms of anorexia nervosa and bulimia nervosa, whereas observing predicted higher anorexic symptoms. Besides, Lavender et al. (2011) found that non-reactivity, acting with awareness, and non-judging each uniquely predicted lower anorexic symptoms, whereas describing was related to higher symptoms (Lavender et al., 2011).

Correspondingly, psychological flexibility has been found to be inversely associated with disordered eating cognitions (Masuda et al., 2010) and disordered eating symptoms (Rawal, Park, & Williams, 2010). Several studies have also found evidence supporting the effectiveness of acceptance-based interventions that improve both psychological flexibility and mindfulness skills, reporting their usefulness in managing weight and improving eating behaviors (Forman, Butryn, Hoffman, & Herbert, 2009; Forman et al., 2013; Gregg, Callaghan, Hayes, & Glenn-Lawson, 2007; Lillis, Hayes, Bunting, & Masuda, 2009; Tapper et al., 2009). In the study by Lillis et al. (2009), 3 months after a 1-day workshop, weight losers exposed to a 6-hr acceptance and commitment therapy condition improved significantly more than those on a waitlist on obesity-related stigma, quality of life, psychological distress, and body mass, as well as in distress tolerance, and both general and weight-specific acceptance and psychological flexibility. Mediational analyses indicated that changes in weight-specific psychological flexibility mediated changes in outcomes. Thus, both mindfulness and psychological flexibility seem to be associated with eating behavior. However, as pointed out earlier, different facets of mindfulness may be differently associated with eating behaviors. As a consequence, it could be argued that although mindfulness and psychological flexibility are closely related phenomenon, there could be some distinct factors that are associated with eating behaviors. Previous research has also suggested that psychological flexibility specific to weight concerns and general psychological flexibility may be related but distinct processes affecting eating behaviors (Lillis & Hayes, 2008; Lillis et al., 2009). On the basis of this, more studies investigating simultaneously both general and weight-specific psychological flexibility in relation to eating behavior (e.g., intuitive eating) are needed.

The objective of the present study was to investigate the relationships between psychological flexibility, mindfulness, and intuitive eating among overweight persons experiencing health concerns. Although psychological flexibility and mindfulness are often theorized to be similar but distinct processes, evidence supporting this conceptual position is still limited. We were interested in whether mindfulness and psychological flexibility (general and weight-specific) uniquely and separately account for intuitive eating or perhaps uniquely and separately account for variance in some forms of eating behavior but not others.

In line with this reasoning, the following research questions were posed and hypotheses formed:

Research Question 1: How are mindfulness skills, psychological flexibility, intuitive eating, and BMI related to each other?

Method

Measurements

Participants completed an Internet-based survey that included the requested self-report measures. Body weight and height were measured at a laboratory visit, at the three local research centers in Jyväskylä, Kuopio, and Helsinki. Body weight was measured using the same type of calibrated electronic scale at each of the research centers. A height gauge was used for height measurement. The BMI was calculated based on the collected height and weight data.

Intuitive eating

The Intuitive Eating Scale (IES; Tylka, 2006) is a 21-item instrument containing three subscales that assess the components of intuitive eating: (a) unconditional permission to eat (nine items; for example, “If I am craving a certain food, I allow myself to have it”); (b) eating for physical rather than emotional reasons (six items; for example, “I stop eating when I feel full [not overly stuffed]”), and (c) reliance on internal hunger and satiety cues (six items; for example, “I trust my body to tell me how much to eat”). Participants rated items on a 5-point scale ranging from 1 (strongly disagree) to 5 (strongly agree). Subscale items were averaged, with higher scores indicating higher levels of intuitive eating.

Mindfulness

The Five Facet Mindfulness Questionnaire (FFMQ; Baer et al., 2006) is a 39-item measure of the general tendency of being mindful in daily life. This measure was derived from an exploratory factor analysis of several previously developed mindfulness questionnaires (Baer et al., 2006) and measures the following five elements of mindfulness: (a) observing—includes noticing or attending to internal and external experiences, such as sensations, cognitions, emotions, sights, sounds, and smells; (b) describing—involves labeling internal experiences with words; (c) acting with awareness—represents attending to one’s activities of the moment and can be contrasted with behaving mechanically or automatically while attention is focused elsewhere (often called automatic pilot); (d) non-judgment of inner experiences—represents taking a non-evaluative stance toward feelings and thoughts; (e) non-reactivity to inner experiences—is the tendency to allow thoughts and feelings to come and go without getting carried away by or caught up in them. The items were rated on a 5-point Likert-type scale ranging from 1 (never or very rarely true) to 5 (very often or always true), with higher scores indicating higher levels of mindfulness. These five facets have been shown to be internally consistent and correlated in expected directions with numerous other constructs in several samples. To a large extent, regression, mediation, and confirmatory factor analyses have supported the construct validity of FFMQ scores (Baer et al., 2006; Baer et al., 2008). Exceptions have been seen with respect to the observing scale, which has shown differential relationships with other variables in meditating and non-meditating sample populations. In student samples, observing has shown either positive or non-significant correlations with psychological symptoms, suggesting that people without meditation experience may tend to observe their internal experiences in a judgmental or reactive way that is not consistent with mindfulness (Baer et al., 2008).

Psychological flexibility

Psychological flexibility was assessed using the general Acceptance and Action Questionnaire (AAQ-II; Bond et al., 2011) and the Acceptance and Action Questionnaire for Weight (AAQW; Lillis & Hayes, 2008). The AAQ-II (Bond et al., 2011) is a 7-item Likert-type questionnaire that assesses the ability to accept aversive internal experiences and to pursue goals in the presence of these experiences. Some items target emotional acceptance or avoidance whereas others address the tendency to become entangled in thoughts, to take them literally, or, conversely, to see them simply as thoughts; still others ask about the ability to take value-based actions in the presence of difficult thoughts, or about the tendency to become behaviorally inactive or avoidant. The questions of the AAQ-II are based on statements such as “I worry about not being able to control my worries and feelings” and “My thoughts and feelings do not get in the way of how I want to live my life.” The items were rated on a 7-point Likert-type scale ranging from 1 (never true) to 7 (always true), with higher scores indicating lower levels of psychological flexibility, that is, higher levels of experiential avoidance.

In previous research, it has been found that the mediation of specific acceptance and commitment therapy (ACT) protocols by ACT processes is better assessed by modifying the general AAQ to target the specific area (e.g., Gifford et al., 2004; Gregg et al., 2007). For that reason, the present study also used a targeted measure adapted from the original AAQ. The AAQW (Lillis & Hayes, 2008) is a 22-item, Likert-type scale that measures acceptance levels of weight-related thoughts and feelings and the degree to which they interfere with valued actions (e.g., “I try hard to avoid feeling bad about my weight or how I look”). The items were rated on a 7-point Likert-type scale ranging from 1 (never true/not at all believable) to 7 (always true/completely believable), with higher scores indicating lower levels of psychological flexibility, that is, higher levels of experiential avoidance.

The measures were written in Finnish. The IES was translated and back translated by experts in nutrition and eating behavior. The other scales were translated by a group of researchers with long experience in acceptance-, mindfulness-, and value-based interventions. The internal consistency of all the applied measures was high (Cronbach’s α = .70-.94, Table 1).

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Table 1.

Means, Standard Deviations, Coefficient Alphas, and Correlations Between Mindfulness Facets, Psychological Flexibility, Psychological Flexibility for Weight, Intuitive Eating Factors, and BMI.

	1	2	3	4	5	6	7	8	9	10	11	12
1. FFMQ	—
2. Observe	.47***	—
3. Describe	.73***	.32***	—
4. ActAware	.72***	.26**	.30***	—
5. Non-judge	.68***	−.18*	.37***	.36***	—
6. Non-react	.80***	.30***	.45***	.46***	.51***	—
7. AAQ-II	−.67***	−.07	−.43***	−.41***	−.71***	−.66***	—
8. AAQW	−.52***	−.07	−.29***	−.33***	−.60***	−.48***	.60***	—
9. IES: Permission	.23**	−.15	.14*	.17*	.41***	.18*	−.26***	−.61***	—
10. IES: Reasons	.28***	.07	.12*	.21**	.31***	.22***	−.29***	−.56***	.61***	—
11. IES: Cues	.32***	.19*	.16*	.25***	.19**	.32***	−.16*	−.44***	.21**	.29***	—
12. BMI	.00	.03	−.01	.082	−.034	−.036	.020	.261***	−.19**	−.14*	−.20**	—
M	132.4	26.1	29.5	26.0	28.5	22.3	20.2	86.4	3.1	2.5	3.2	31.3
SD	19.0	5.2	6.7	5.9	6.7	5.0	8.8	21.1	0.6	0.8	0.6	3.0
α	.91	.72	.94	.89	.90	.84	.91	.90	.70	.86	.76

Note. Means, standard deviations, and correlations are calculated using Mplus software with full information maximum likelihood estimates for the parameters. BMI = body mass index; FFMQ = Five Facet Mindfulness Questionnaire; AAQ-II = Acceptance and Action Questionnaire; AAQW = Acceptance and Action Questionnaire for Weight; IES = Intuitive Eating Scale; permission = unconditional permission to eat; reasons = eating for physical reasons; cues = reliance on hunger/satiety cues.

*

p < .05. **p < .01. ***p < .001.

Results

Explaining Variance in Intuitive Eating

The models provided either a good or reasonable fit with the data (data not shown).

To study the extent to which psychological flexibility and mindfulness accounted for unique variances in intuitive eating, we conducted a hierarchical regression analysis involving Cholesky decomposition. First, we examined whether mindfulness skills explain intuitive eating (IES factors) when controlling for psychological flexibility (AAQ-II and AAQW). The first row in Table 2 shows to what extent the AAQ-II explains the variance between the IES factors. The second row shows how the AAQW explains the variance between IES factors when the AAQ-II was controlled for. Finally, the third row shows how particular mindfulness skills explain the variance between IES factors when both the AAQ-II and AAQW were controlled for. The coefficient of determination (R²) is the sum of the squares of the standardized regression coefficients and indicates to what extent these variables jointly explain the variance between the intuitive eating factors. For example, the AAQ-II, AAQW, and the component acting with awareness explain 39.4% of the variance between the measure unconditional permission to eat, of which the AAQ-II explains 7.1% and the AAQW 32.3%.

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Table 2.

Standardized Regression Coefficients of Hierarchical Modeling Between IES Factors and Independent Factors in Examining Whether Mindfulness Facets Explain Intuitive Eating Factors When Controlling for Psychological Flexibility.

Model	IES: Unconditional permission to eat	IES: Eating for physical reasons	IES: Reliance on hunger/satiety cues
1. AAQ-II	−.266***	−.296***	−.167*
2. AAQW	−.568***	−.476***	−.424***
3. ActAware	−.001	.044	.150*
R 2	.394	.316	.231
1. AAQ-II	−.263***	−.294***	−.166*
2. AAQW	−.570***	−.478***	−.424***
3. Observe	−.178**	.038	.169*
R 2	.426	.316	.236
1. AAQ-II	−.271***	−.299***	−.169*
2. AAQW	−.566***	−.474***	−.423***
3. Describe	.001	−.016	.096
R 2	.393	.314	.217
1. AAQ-II	−.270***	−.300***	−.171*
2. AAQW	−.565***	−.473***	−.423***
3. Non-react	−.093	−.035	.222**
R 2	.401	.316	.257
1. AAQ-II	−.269***	−.296***	−.167*
2. AAQW	−.566***	−.476***	−.424***
3. Non-judge	.123	−.009	−.015
R 2	.408	.314	.208

Note. IES = Intuitive Eating Scale; AAQ-II = Acceptance and Action Questionnaire; AAQW = Acceptance and Action Questionnaire for Weight.

*

p < .05. **p < .01. ***p < .001.

These results indicate that even though mindfulness skills seem to be related to all of the IES factors, mindfulness skills accounted for mainly the same variance as psychological flexibility in regard to eating for physical reasons and unconditional permission to eat. Only observing shared some additional variance with unconditional permission to eat. When the levels of psychological flexibility (AAQ-II and AAQW) were controlled for, observing showed an inverse relation to unconditional permission to eat, indicating that persons who observe their internal and external experiences more have less unconditional permission to eat. Acting with awareness, observing, and non-reacting explained reliance on hunger/satiety cues when psychological flexibility and psychological flexibility for weight were controlled for, indicating that these mindfulness skills involve features explaining intuitive eating that are not shared with psychological flexibility.

Second, it was examined whether psychological flexibility explains intuitive eating (IES factors) when controlling for mindfulness skills. This model was formed by setting all five mindfulness facets first, followed by the items of the AAQ-II and AAQW (Table 3). In Table 3, row 6 indicates that when all five mindfulness skills were controlled for, the general psychological flexibility did not explain intuitive eating; but, as seen in row 7, the AAQW explained all intuitive eating factors independently of mindfulness skills and the AAQ-II.

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Table 3.

Standardized Regression Coefficients of Hierarchical Modeling Between IES Factors and Independent Factors in Examining Whether Psychological Flexibility Explains Intuitive Eating Factors When Controlling for All Mindfulness Facets.

Model	IES: Unconditional permission to eat	IES: Eating for physical reasons	IES: Reliance on hunger/satiety cues
1. ActAware	.167*	.210**	.249***
2. Observe	−.184*	.033	.143
3. Describe	.144*	.062	.071
4. Non-react	.283***	.266***	.151*
5. Non-judge	−.016	.009	.148*
6. AAQ-II	−.011	−.088	.110
7. AAQW	−.520***	−.441***	−.363***
R 2	.433	.322	.276

Note. IES = Intuitive Eating Scale; AAQ-II = Acceptance and Action Questionnaire; AAQW = Acceptance and Action Questionnaire for Weight.

*

p < .05. **p < .01. ***p < .001.

Third, it was examined whether psychological flexibility explains intuitive eating (IES factors) when controlling for particular mindfulness skills (Table 4). In these models, row 2 shows how the AAQ-II explained the IES factors when particular mindfulness skills were controlled for, while row 3 shows how the AAQW explained IES factors when both particular mindfulness skills and the AAQ-II were controlled for. General psychological flexibility explained unconditional permission to eat and eating for physical reasons independently from single mindfulness facets, apart from non-judgment, indicating that connections between general psychological flexibility and unconditional permission to eat as well as eating for physical reasons overlap with non-judgment. General psychological flexibility shared additional variance with reliance on hunger/satiety cues only after observing was controlled for, indicating that psychological flexibility (AAQ-II) did not explain reliance on hunger/satiety cues when any other mindfulness skill was controlled for.

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Table 4.

Standardized Regression Coefficients of Hierarchical Modeling Between IES Factors and Independent Factors in Examining Whether Psychological Flexibility Explains Intuitive Eating Factors When Controlling for Individual Mindfulness Facets.

Model	IES: Unconditional permission to eat	IES: Eating for physical reasons	IES: Reliance on hunger/satiety cues
1. ActAware	.167*	.210**	.249***
2. AAQ-II	−.217**	−.217**	−.072
3. AAQW	−.565***	−.468***	−.405***
R 2	.394	.316	.231
1. Observe	−.146	.069	.191*
2. AAQ-II	−.271***	−.290***	−.157*
3. AAQW	−.575***	−.476***	−.418***
R 2	.426	.316	.236
1. Describe	.137*	.129*	.175**
2. AAQ-II	−.235***	−.270***	−.106
3. AAQW	−.565***	−.474***	−.418***
R 2	.393	.314	.217
1. Non-react	.168*	.221***	.323***
2. AAQ-II	−.212**	−.206**	.055
3. AAQW	−.573***	−.474***	−.387***
R 2	.401	.316	.257
1. Non-judge	.396***	.306***	.200**
2. AAQ-II	.014	−.113	−.037
3. AAQW	−.500***	−.456***	−.408***
R 2	.408	.314	.208

Note. IES = Intuitive Eating Scale; AAQ-II = Acceptance and Action Questionnaire; AAQW = Acceptance and Action Questionnaire for Weight.

*

p < .05. **p < .01. ***p < .001.

Discussion

The purpose of the present study was to provide a complementary understanding of the processes creating intuitive eating by investigating the relationships between psychological flexibility, mindfulness, and intuitive eating within overweight individuals with health concerns. Consistent with our hypotheses, better psychological flexibility was related to better mindfulness skills, and higher levels of psychological flexibility and mindfulness were related to higher levels of intuitive eating. An exception to this was the mindfulness facet observe, which did not correlate on its own with any study variables other than reliance on hunger and satiety cues, showing that persons who attend more to their internal and external experiences rely more on their body’s hunger and satiety cues. BMI correlated with the AAQW (but not with the general psychological flexibility, AAQ-II) and all intuitive eating factors, indicating that persons who had a lower BMI had higher acceptance of weight-related thoughts and feelings and they practiced more intuitive eating, which is in accordance with previous research in female college students (Hawks et al., 2005; Smith & Hawks, 2006), early and mid-age women (Augustus-Horvath & Tylka, 2011; Tylka, 2006), and young adults in both genders (Denny et al., 2013).

The current study contributes to the existing understanding of regulation processes underlying eating behavior by suggesting that mindfulness and psychological flexibility are related constructs that account for some of the same variance in intuitive eating, as well as accounting for significant unique variances in this type of eating behavior—especially when psychological flexibility is assessed with a targeted measure of weight-related thoughts and feelings.

The present results show that general psychological flexibility explains unconditional permission to eat and eating for physical reasons separately from single mindfulness skills, apart from non-judgment. This indicates that non-judgment can explain the relationship between general psychological flexibility and unconditional permission to eat as well as eating for physical reasons. Obviously, as the name Acceptance and Action Questionnaire indicates, acceptance (i.e., non-judgment) is an essential process of psychological flexibility. Anyhow, our findings suggest that the ability to take a non-evaluative stance toward feelings and thoughts is associated with a more flexible and accepting relationship with food and lower emotional eating.

The relationship between general psychological flexibility (AAQ-II) and reliance on hunger/satiety cues was overlapping with all other mindfulness skills except observing, indicating that general psychological flexibility does not explain reliance on hunger/satiety cues when any other mindfulness skill is controlled for. Instead, mindfulness skills—acting with awareness, observing, and non-reacting—explained reliance on hunger/satiety cues independently from psychological flexibility (AAQ-II and AAQW). In other words, regardless of the level of psychological flexibility, the ability to attend to internal and external experiences (observe), the ability to attend to one’s activities in the moment (acting with awareness), and the tendency to allow thoughts and feelings to freely come and go (non-reacting), were related to reliance on internal hunger and satiety cues to determine when and how much to eat. Seen together, these results suggest that acceptance is an important process that explains unconditional permission to eat and eating for physical reasons, whereas acting with awareness, observing and non-reacting better explain reliance on hunger and satiety cues. Thus, mindfulness skills seem to be especially relevant for intuitive eating based on sensing bodily cues and relying on them to determine when and how much to eat. This is in line with previous results showing that the individual degree of accurately perceiving one’s interoceptive signals (e.g., heartbeat) predicted the total IES score and especially the results of the subscales associated with the awareness of hunger and satiety cues and the willingness to eat to satisfy hunger rather than to eat for external and emotional reasons (Herbert, Blechert, Hautzinger, Matthias, & Herbert, 2013).

Moreover, when psychological flexibility (AAQ-II and AAQW) was controlled for, the observe item was inversely associated with unconditional permission to eat, indicating that persons who observe their internal and external experiences more tend to show greater eating restraint. These results regarding the observe item (the positive correlation to reliance on hunger and satiety cues and the negative correlation to unconditional permission to eat) suggest that individuals who notice their present-moment experience more also notice when they are hungry or full, but might have stricter rules that guide their eating and consequently make them feel guilty about eating “bad” foods. These findings, together with the notion that observing was not related to psychological flexibility, are consistent with previous findings showing that although most aspects of mindfulness predict better psychological outcomes, observing does not (Baer et al., 2006; Lavender et al., 2011). Lattimore et al. (2011) also found that observing was positively associated to uncontrolled eating and cognitive restraint of eating (Lattimore et al., 2011). Adams et al. (2012) found that describing and non-judging predicted lower symptoms of bulimia nervosa and lower body dissatisfaction, and acting with awareness was positively related to lower symptoms of anorexia nervosa and bulimia nervosa, whereas observing predicted higher anorexic symptoms. Seen together, these results suggest that simply observing one’s present-moment experience is not necessarily beneficial to healthy eating behavior unless it is combined with other aspects of mindfulness (i.e., a non-judgmental, non-reactive stance toward those experiences).

Although general psychological flexibility (AAQ-II) seems to overlap with mindfulness skills in relation to intuitive eating, psychological flexibility for weight (AAQW) seems to involve features explaining intuitive eating that are not shared with mindfulness skills and general psychological flexibility. This targeted measure of flexibility could explain eating behavior when controlling for more general processes (AAQ-II and FFMQ). This observation supports the idea of modifying the general AAQ-II to target this specific area (Lillis & Hayes, 2008). In the context of the present study, the acceptance of weight-related thoughts and feelings and the degree to which these interfere with valued actions is probably a more valid issue than the aspect of struggling with aversive internal experiences in general. However, it is interesting that the general regulation processes of psychological flexibility and mindfulness also explain eating behavior.

Clinically, the present study suggests that mindfulness and psychological flexibility play a role in promoting healthy eating behavior and considering this role can contribute to treating disordered eating behavior. The present findings suggest that interventions should not only target eating behavior but that it would be useful to also target potential underlying processes, such as psychological flexibility and mindfulness skills. Thus, the findings imply that further studies of interventions that target both mindfulness and psychological flexibility might be fruitful. Studies of this nature are essential to understanding the mechanisms by which mindfulness and psychological flexibility may promote more adaptive eating behavior in an obesogenic environment. According to the present findings, the tendency to be conscious of one’s internal and external experiences (observing) and attend to one’s activities in the moment (acting with awareness), as well as allowing thoughts and feelings to come and go without getting carried away by or caught up in them (non-reacting), are related to the sensing of one’s bodily cues and relying on them to know when, what, and how much to eat. In contrast, our findings indicate that the ability to accept aversive internal experiences is related to unrestricted eating and eating for physical reasons instead of emotional reasons. These clinical implications are consistent with recent studies showing that intuitive eating (Tylka, 2006), mindfulness, and psychological flexibility (Lavender, Jardin, & Anderson, 2009; Rawal et al., 2010) are inversely related to disordered eating behavior.