Motivational profiles for eating behaviour and their associations with intuitive eating and body mass index in New Zealand women
Background: According to self-determination theory (SDT) there are six different qualities of motivation: amotivation (lack of any intention to engage in the behaviour), external regulation (motivated by pressure exerted by others, such as rewards, demands, avoiding criticism), introjected regulation (motivated by pressure that is self-imposed, such as guilt, shame, rebellious feelings), identified regulation (motivated by a personally valued outcome of the behaviour), integrated regulation (motivated by the behaviour fitting with one’s personal values and beliefs) and intrinsic motivation (inherent satisfaction or enjoyment in the behaviour). The first three qualities of motivation are referred to as controlled motivation (amotivation, external regulation, and introjected regulation) and the latter three as autonomous motivation (identified regulation, integrated regulation, and intrinsic motivation). SDT proposes that an individual’s motivation for eating behaviour can be represented by a motivational profile consisting of varying levels of the six different qualities of motivations. However, the majority of studies on this topic have either examined each quality of motivation separately, as global autonomous and controlled scores, or as self-determination index scores. Although of interest, these studies do not directly test the SDT hypothesis that different qualities of motivation coexist within an individual to varying degrees. No published study has explored motivational profiles for eating behaviour. Objective: The aim of the study was to examine, in a nationwide sample of adult New Zealand women, motivational profiles based on the various qualities of motivation for eating from SDT. The first objective was to identify women with different motivational profiles. The second objective was to examine and compare the derived profiles in terms of intuitive eating, binge eating, intake of fruits and vegetables, intake of high fat and/or high sugar foods, and body mass index (BMI). Design: This cross-sectional study was conducted in a nationwide sample of New Zealand women (n = 1,447) aged 40 to 50 years. Latent profile analysis was used to identify motivational profiles and chi-square analysis was used to compare the profiles on the outcome variables. Results: Seven profiles were identified which were characterised by varying levels of controlled and autonomous motivation relative to the sample mean: ‘very low autonomous motivation’; ‘low autonomous motivation’; ‘high autonomous motivation’; ‘very high autonomous motivation’; ‘balanced motivation’; ‘amotivated, very high controlled motivation’; and ‘amotivated, very high controlled and very high autonomous motivation’. Women belonging to the ‘high autonomous motivation’ and ‘very high autonomous motivation’ profiles (both of which were characterised by higher levels of autonomous motivation relative to controlled motivation) had higher intuitive eating scores, less frequent binge eating, healthier food intake, and lower BMI. Women belonging to the ‘very low autonomous motivation’, ‘low autonomous motivation’, ‘amotivated, very high controlled motivation’, and ‘amotivated, very high controlled and very high autonomous motivation’ profiles (all of which were characterised by higher levels of controlled motivation relative to autonomous motivation) were found to have less favourable outcomes. Women belonging to the ‘balanced motivation’ profile had less favourable outcomes than those belonging to the more autonomous profiles, but more favourable outcomes than those belonging to the more controlled profiles. Conclusion: The results show that in middle-aged New Zealand women, having a motivational profile higher in autonomous motivation relative to controlled motivation is associated with higher intuitive eating scores, less frequent binge eating, healthier food intake, and lower BMI. The results provide support for the importance of autonomous motivation in facilitating healthier eating habits and lower BMI in middle-aged women.
Advisor: Horwath, Caroline; Hargreaves, Elaine
Degree Name: Master of Dietetics
Degree Discipline: Human Nutrition
Publisher: University of Otago
Keywords: New Zealand; self-determination theory; controlled motivation; autonomous motivation; non-diet; intuitive eating
Research Type: Thesis