Adolescents' self-determination to regulate eating behaviors : adaptation and validation of a self-report measure

The aim of this study was to adapt a measure of eating behavior regulation developed for use with adult females, the Regulation of Eating Behavior Scale (REBS), for use with mixed-gender, adolescents. The study aimed to evaluate the psychometric properties of the adapted measure and to evaluate how responses differed across races/ethnicities and genders. Responses were examined in a sample of 261 adolescents across the United States. The factor structure was examined using exploratory (n=150) and confirmatory factor analyses (n=100). A two-factor model was identified as the best fit for the data in both analyses and using multiple fit indices. The revised measure demonstrated good internal consistency and validity. Subscale scores did not differ across gender or ethnicity for more intrinsic forms of eating behavior regulation, but they were significantly different across extrinsic forms of eating behavior regulation. The measure can be applied for use in future research to better understand properties of adolescent eating behavior regulation. Conclusions, implications, and future directions are discussed. ASSESSMENT OF EATING BEHAVIOR REGULATION IN ADOLESCENCE 41 Assessment of Eating Behavior Regulation in Adolescence In the fall of 2018, Huffington Post journalist Michael Hobbes published an article entitled “Everything You Know about Obesity is Wrong.” The article was debated widely in subsequent opinion-editorial articles and on social media in weeks and months following (e.g., Markey, 2018). One of the most prominently displayed quotes in the article speaks to Hobbes’ (2018) experience in writing the piece: I have never written a story where so many of my sources cried during interviews, where they shook with anger, describing their interactions with doctors and strangers and their own families (para. 7). Hobbes’ quote highlights the need for enhancing researchers’ and clinicians’ capacity to more effectively support the social and emotional processes that are associated with eating and weight regulation. Longitudinal assessments suggested that the majority of adolescents had experience in one more of the following areas at some point by the time they reached adulthood,: Employing unhealthy weight control mechanisms; high levels of body dissatisfaction; or classification according to medical standards as being overweight (Neumark-Sztainer, Wall, Chen, Larson, Christoph, & Sherwood, 2018). Eating disorders and body dissatisfaction have generally been regarded as areas of research and intervention that are separate from the study of excess weight; however, these findings highlight the potential benefits of efforts that marry these (Irving & Neumark-Sztainer, 2002). In light of these findings, the assessment of affective and motivational processes that govern eating behavior regulation may better support researchers in accounting for internal, affective processes that support health-promoting behaviors. Eating behavior regulation (EBR) can be characterized as the adjustment or influence of nutrient consumption patterns by engaging in processes of self-observation, self-judgment, and self-reaction (Schunk, 2008). Understanding ASSESSMENT OF EATING BEHAVIOR REGULATION IN ADOLESCENCE 42 the factors that influence EBR may better equip researcher and clinicians to address conditions that can both positively and negatively impact the biopsychosocial functioning of adolescents. Unification of weight and eating disorder efforts will require that researchers develop novel definitions that encompass notions across both bodies of research. Thus, for the purposes of this work, healthy eating is conceptualized as dietary practices that promote or enhance an individual’s biopsychosocial wellness, and are consistent with their unique cognitive, psychological, physiological needs and support sociocultural standards for nourishment and daily living (Levine et al., 2016; Taylor, Evers, & McKenna, 2005; World Health Organization, 2018). In addition, classification of healthy weight status may also require reconsideration. Rodgers (2016) suggests that formerly biomedical classifications of a “Healthy Weight” have resulted in a sociocultural internalization of attitudes and beliefs about body size, which can be accompanied with problematic body image and eating disorder concerns. For the purposes of this study, a healthy weight is considered a self-determined construct—the body mass at which a person is able to achieve a maximal level of physiological and psychological health and at a level of functioning consistent with their individual and sociocultural functioning. Self-Determination Theory, Motivation, and Adolescent Eating Behavior Regulation An understanding of the regulatory patterns proposed by self-determination theory (Deci & Ryan, 1985, 2002; Ryan & Deci, 2000) has relevance to the study of adolescent EBR. Selfdetermination, as conceptualized by Deci and Ryan (1985) is “the capacity to choose and to have those choices, rather than reinforcement contingencies, drives, or any other forces or pressures, be the determinants of one’s actions” (p. 38). In this regard, higher levels of self-determination are regarded as more intrinsic, autonomously driven behaviors (Deci & Ryan, 1985; 2002; Ryan & Deci, 2000). By contrast, controlled regulation involves management of behaviors, that are ASSESSMENT OF EATING BEHAVIOR REGULATION IN ADOLESCENCE 43 not perceived as being selected or chosen by an individual, through the use of external consequences, pressure/influence, or contingencies (Deci & Ryan, 2002; Ryan & 2000; Pelletier, Dion, Slovenic-D’Angelo, & Reid, 2004). In prior studies, level of self-determination to modify eating behaviors was assessed among adult Canadian individuals, identified as at-risk for coronary artery disease and enrolled in a weight reduction intervention program (Pelletier et al., 2004). At the conclusion of the 26week intervention, higher levels of self-determination to change eating behaviors were associated with a greater reduction in saturated fat/total fat consumption, body weight (among individuals for whom this was an identified goal) and reductions in blood lipid parameters (Pelletier et al., 2004). Pelletier et al. (2004) observed similar relationships between self-determination and numerous constructs within adult Canadian undergraduate women; for example, participants with higher self-determination to regulate their eating were more likely to care about the quality of their food (r=.43) as opposed to quantity (r=.18). The opposite relationship was observed among participants with more controlled eating regulation where the concern for quantity (r=.41) was more strongly and positively correlated than the concern for quality (r=.21; Pelletier et al., 2004a). Importantly, lower levels of self-determination were positively correlated with bulimic symptomology (r=.68) and depressive symptomology (r=.43; Pelletier et al., 2004a). In addition, some research has demonstrated a motivational “spill over” effect across eating and exercise behaviors, such that interventions targeting exercise motivation also led to increases in selfdetermined EBR (Mata et al., 2009). Finally, adolescence often marks the emergence of awareness, interest, and motivation to alter one’s food consumption or weight status, especially among females (Rolls, Fedoroff, & ASSESSMENT OF EATING BEHAVIOR REGULATION IN ADOLESCENCE 44 Guthrie, 1991). However, the regulatory patterns associated with adolescents’ eating behaviors have not been sufficiently explored. Taken together, these findings highlight the important role assessing affective processes can play in adolescent wellness promotion. Prior research related to eating behavior change among adolescents has generally examined treatment outcomes without regard for the affective or motivational processes that underlie these results. For example, Austin, Field, and Wiecha (2012) found that female adolescents enrolled in the Planet Health interdisciplinary obesity prevention program were less than half as likely to engage in purging or to use diet pills as adolescents in a comparison group. The Planet Health intervention also reduced the odds for being classified as overweight according to medical standards over two subsequent school years. Despite overlooking the motivational components, the findings from Planet Health may be the first evidence of the efficacy of the integration of overweight and eating disorder prevention (Austin et al., 2012). However, Austin et al. (2012) also noted that it was unknown what specific components of the program were responsible for these changes, and many questions remain about the mechanisms that resulted in a shift in adolescents’ EBR. Thus, assessment of motivational properties can provide supplemental information about the key components of interventions, environments, or subcultures that are wellness-enhancing. The Regulation of Eating Behavior Scale (REBS) Pelletier et al. (2004) applied the tenets of SDT and notions of internal versus external regulators of eating behavior to develop the REBS. Respondents rated the extent to which each item corresponded to their motives for regulating their eating on a 7-point scale (Pelletier et al., 2004; see Appendix A). This measure could provide an opportunity for researchers and clinicians to better understand affective and motivational properties of EBR. In addition, the REBS allows ASSESSMENT OF EATING BEHAVIOR REGULATION IN ADOLESCENCE 45 for conceptualization of EBR across the SDT spectrum of motivation; that is, it allows for an assessment of self-determination to regulate eating behavior ranging from least-to-most autonomously regulated. As stated, assessing self-determination and the degree to which it is intrinsic versus extrinsic may allow researchers and clinicians to better understand why interventions are or are not effective and how to differentially support individuals depending upon thei