Design

An interpretive paradigm guided the research using a relativist ontological view [29]. Being relativists, the researchers understand that reality is constructed intersubjectively and developed socially and experientially [29]. The relativist viewpoint was demonstrated by gaining the perspective of people about their individual dietetic consultations and the dietary changes they made, which have been given meaning based on their own experience and view on reality. The researchers have a subjectivist epistemological position, as knowledge is created subjective to those who experience it [29]. Knowledge was obtained by actively being involved in the research process [29]. An interpretive descriptive methodology was used [29]. Therefore, theoretical thematic analysis was conducted to give meaning to the data.

Semi-structured telephone interviews were conducted with free-living individuals (i.e., not part of a controlled intervention) across Australia to explore the experience of consulting with a dietitian after a new diagnosis of T2D. The data collection took place between October 2019 and February 2020 in Southeast Queensland, Australia, in a workplace setting with no other researchers or nonparticipants present. The Consolidated criteria for Reporting Qualitative research (COREQ) checklist and the APA Journal Article Reporting Standards for qualitative research [30] guided the reporting of this qualitative study (see S1 Table) [31]. This study was approved by the Griffith University Human Research Ethics Committee (reference 2017/951).

Participants

Eligible individuals were those newly diagnosed with T2D who were participating in a 12-month observational study with no intervention (Diet after a Diagnosis of type 2 Diabetes: The 3D Study [32]). The 3D Study obtained information on demographic, physical, and social psychological factors of 225 individuals newly diagnosed with T2D [32]. While author RR was involved in collecting data for the 3D Study, this did not impact the current study as no prior relationships were knowingly established. Only the participants who consented to participate in further research were included in the potential recruitment pool for the current study (see S1 Fig for the flow of recruitment). Purposive sampling from the 3D Study participant database was used to invite participation from people newly diagnosed with T2D who had consulted with a dietitian for dietary advice after their diagnosis on one or more occasions as it enabled the selection of information-rich cases [32].

Potential participants (n = 42) were invited by author RR via email, which included a participant information sheet and consent form and notification that the study was a component of the author’s (RR) PhD research. The information and consent formed outlined that agreeing to participate was implied consent. Twelve individuals did not respond to any recruitment contacts, and one individual sent an email indicating declined participation. Two participants did not answer their interview call and were uncontactable afterwards. The final number of participating subjects was 21.

Interview guide development

A semi-structured interview guide was developed using open-ended questions to stimulate discussion about the participant’s retrospective experience of consulting with a dietitian (e.g., “Let’s now focus on your time with the dietitian, can you tell me about that and your experiences.”) and the influences on their dietary change (e.g., “What helped you to make the decision to make those [dietary] changes?”) (see S2 Table). Formulation of the interview protocol was informed by previous work in this area [33], the expertise of the research team, and the overarching interview topics that guided the study. To enhance qualitative credibility [34], participants were prompted to recall specific situations where they had made changes to their diet just after their diagnosis, either self-enacted or as a result of consultation with a dietitian and to discuss whether changes were made before and after seeing their dietitian (e.g., “Now let’s focus on your diet and foods choices after your T2D diagnosis. I’d like you now to tell me about your experiences after you’ve been diagnosed with T2D”). To provide a balanced view of their experience, the participants were asked to elaborate on aspects that were and were not helpful, including any affective responses to this. Further exploration into these self-enactment behaviours and their influences will be reported separately in a subsequent paper.

Interview protocol

Participants undertook a single semi-structured telephone interview with author RR, a female PhD candidate and Accredited Practising Dietitian, with honours-level experience and post-graduate studies in qualitative research. Interview times were arranged via email and conducted at a time convenient to the participant. Author RR’s PhD research is in behavioural science in dietetics. She was previously involved in the 3D Study data collection, which likely shaped her interpretation of the current study’s data. Interviews lasted between 18 and 40 minutes (mean length 26 minutes). Each participant received an AU$20 gift-card to thank them for their participation.

At the beginning of each interview, participants were informed of the process and content of the interview and provided with a working definition of “dietary behaviours” as: “… your food choice, eating behaviours and habits, and specific dietary or nutrition intakes”. Then the participants were asked to expand on how a dietitian influenced these dietary behaviours (i.e., probe: “In what ways did your dietitian help you make dietary changes?”). The interviewer summarised the discussion with each participant to ensure the qualitative validation of collected information [35] and invited each participant to modify or elaborate on this summary. Participants consented for the interviews to be audio recorded, using a digital voice recorder and transcribed verbatim for data analysis. To ensure participant anonymity, all interview recordings were permanently deleted after being transcribed. Notes were made by the interviewer during each interview to explore relevant concepts further. These notes were not provided to participants. Transcription was initially in a Microsoft Word document and then imported into a Microsoft Excel file for data analysis.

Analysis

A theoretical thematic analysis of transcripts was performed to facilitate the emergence of themes [35]. This method was selected as it is guided by existing theoretical concepts and the researchers’ standpoint and disciplinary knowledge. The six phases of thematic analysis by Braun and Clark (2013) were carried out: data familiarisation through transcribing data, reading and rereading the data; generation of initial codes guided by the theoretical constructs of the analysis guide; identification of themes; review themes; and define and name the overarching themes [35].

The analysis was completed in the context of the theoretical framework used. An analysis guide, developed by author RR and cross-checked by author KH (a behavioural scientist), was based on integrating key psychological constructs from the IBC model [17]. The guide was used to understand concepts that underpin motivational (i.e., involving factors that influence the formation of a conscious intention to change dietary behaviours), volitional (i.e., involving factors that help transition the intention into the behaviour), and implicit (i.e., non-conscious thought processes that can impact behaviour spontaneously) processes that may influence the dietary behaviours of individuals diagnosed with T2D. However, some aspects of participants’ narratives did not fit within the scope of these three broad psychological processes and other concepts, such as emotions and individual difference factors, [5, 16] were identified. Therefore, data coding was flexible to allow new codes that did not fit the broad processes of the IBC model to be added and categories and themes to be re-organised.

Coding and themes were reviewed by author KH (two coders in total) on 33% (n = 7) of the transcripts to identify and resolve any inconsistencies in coding and naming. As the data was collected, coded and analysed in an iterative process, recruitment ceased when the data no longer added anything new to the overall analysis [35]. The participants were not provided with the opportunity to review or comment on themes, nor did they provide feedback on the findings. Still, this learning was noted as a recommendation for future research. The authors reflected on the themes to ensure the concepts aligned theoretically to the motivational, volitional, and implicit processes of the IBC model, taking into account the additional themes that emerged outside of the model. The additional themes that emerged through participants’ narratives aligned with the research question and have been reported in this paper.

Motivational processes

All participants discussed various motivating factors that enabled them to make positive changes to their diet. The motivation stemmed from five key points which are expressed in the motivational themes and included wanting to improve their health status, make changes for themselves and others, making use of social networks, have the ability and responsibility to make changes, and post-diagnosis realisations.

Volitional processes

Through conscious decision making, some participants expressed how they overcame challenges and constraints when trying to change their dietary behaviours. The participants discussed their self-control, how they had coping mechanisms in place, practised self-monitoring, made plans or goals and consciously made dietary choices recommended for T2D. These four key points are expressed in the four volitional themes and two subthemes.

Implicit processes

Implicit processes are suggested to represent more automatic, non-conscious decision making, which requires little conscious effort in undertaking a behaviour. The themes discussed by some of the participants that reflect this process involve unlearning habits and limiting the availability of food in their physical surroundings.

Motivational processes

Some participants described their diagnosis as a wakeup call, which may suggest that a health-risk event could be the impetus needed to drive someone into action; in this context to change dietary behaviour. Findings from the English Longitudinal Study of Ageing found limited evidence to suggest that a T2D diagnosis encourages behaviour change other than for quitting smoking [36]. However, T2D could be suggested to be a ‘teachable moment’, which McBride, Emmons, and Lipkus [37] has defined to occur when individuals adopt risk-reducing behaviours following a health-related event (i.e., T2D diagnosis). This suggestion has been supported in other studies exploring cognitive, emotional, and behavioural changes following a diagnosis of T2D [38]. Such motivational processes can also be understood by reference to constructs that underpin the health belief model [39]. The model postulates that individuals engage in certain behaviours (i.e., dietary behaviour change) because they hold certain beliefs and perceptions regarding their susceptibly and severity of an illness (i.e., T2D) [39]. The theory also proposes cues to action as a precursor of behaviour change, and that the diagnosis of T2D may elicit this cue response. A mixed-method study of adults diagnosed with prediabetes found that some individuals would have made changes earlier, had they known the seriousness of T2D or been referred to a health professional like a dietitian at the time of their prediabetes diagnosis [40]. Addressing the seriousness of T2D well before a diagnosis could influence the likelihood of individuals adopting positive changes and delaying, or reversing, the onset of T2D.

Participants’ beliefs surrounding their ability within themselves to change their dietary behaviours regularly featured in the narratives with several different themes intertwined. This ability highlighted the importance of self-efficacy for dietary change in individuals with T2D. In the health behaviour change literature, an individual’s ability and confidence (i.e., self-efficacy) toward performing a target behaviour is a strong predictor of actual behavioural performance [21] and the participants expressed this in this study. Previous research has found a positive relationship between social support, self-efficacy, and adults’ psychological well-being with T2D [41]. This finding concurs with a cross-sectional study demonstrating that high levels of self-efficacy were associated with diet adherence in adults with T2D [42]. Our results are consistent with these accounts in illustrating that self-efficacy beliefs can shape the dietary changes in individuals with T2D and highlight the importance of enhancing one’s ability and confidence for change.

According to theories of social cognition, humans are social beings and can be heavily influenced to make decisions based on social relatedness and norms [19]. Such influences were identified in the theme making use of their social networks. Social support’s benefits on enabling behaviour change have been well established in the health literature [43, 44] and social cognition models highlight the motivational influence that social support has on intentional behaviours [19]. Social support may also facilitate an individual’s basic psychological need of relatedness, which is one of the central components of self-determination theory [19]. Our findings support this, as those participants who made use of their social networks and felt a sense of connectedness to their family or dietitian also reported making positive changes to their diet. Individuals with T2D often require a high level of support given the complexity of the disease [4], and this support can be received from a range of sources. Our findings are consistent with previous research that has found social support to positively influence a person’s ability to cope with their disease and improve adherence to treatment [44]. Other research has indicated that social support can have a positive or negative influence on diabetes management. For example, a systematic review of observational and intervention studies exploring the impact of social support in adults with T2D highlighted how family members who were perceived to be overprotective and overwhelming could negatively impact a person’s ability to self-manage their diabetes [45]. Although these characteristics were not explicitly mentioned among the current study participants, a lack of support from family members was described as a barrier to change. Interestingly, a study by Oftedal [43] found that adults with T2D experienced demotivation of their diabetes management through emotional support perceived as being non-constructive. In contrast, our study participants expressed emotional support to be constructive and positive to their overall diagnosis and experience with dietary change. These results demonstrate the type of support individuals might receive and provides insight into the potential impact that social support can have on motivation levels.

Volitional processes

It has been suggested that individuals who make conscious and purposeful plans that are specific and measurable may be more inclined to achieve their goals [17]. In this study, the data revealed that participants often made plans that incorporated specific detail to have strategies in place to manage their food choice. In a longitudinal study of undergraduate students, action planning has been shown to have positive effects on dietary behaviour, in particular fruit and vegetable intake [46]. Considering adults with T2D have been found to fall short of the recommended intakes of foods such as fruits and vegetables [3], dietitians and other health care providers should encourage their patients to create detailed action plans to adopt and support recommended dietary behaviours. It was evident that most participants’ recollection of dietary changes was focused on carbohydrate-type foods. However, dietary guidelines and T2D recommendations state that other nutrients are important for T2D management, such as protein and total energy intake [47, 48]. This apparent lack of reporting of other key nutrients suggests that individuals primarily relate T2D management with carbohydrates. It is important that dietitians and other health professionals involved in diabetes care educate patients to understand the appropriate dietary recommendations for T2D and address common ambivalences or lack of importance on other foods.

Other volitional determinants of dietary behaviour change identified in this study included self-monitoring. Our study suggests that individuals who say they are motivated to control their diabetes also report practising self-monitoring (i.e., food diary, blood glucose monitoring) as part of their diabetes management. These findings support the theoretical constructs in the volitional phase of the health action process approach [21] which posits planning and action control (i.e., conscious monitoring and evaluation of actions against a desired behavioural standard) as helping to bridge the intention-behaviour gap by mediating the effect of intentions to actual behaviour [49]. Such self-regulatory practices are evidenced to enhance clinical outcomes [50] and should be a fundamental aspect of dietitians’ nutrition care.

Within the volitional processes leading to a change of dietary behaviour, our participants highlighted the importance of self-control and knowing their limits when dealing with food temptations and having the capacity to manage challenges and setbacks to their diet. Self-control can refer to the capacity and ability an individual has in dealing with temptations, impulses, and habitual responses [51]; however, there are potential limitations on the sustainability of self-control over an extended period. Strength models of self-control show that a person’s ability to have self-control on one occasion may weaken their ability on the next [51]. These findings suggest that individuals who are in the process of making multiple dietary changes should be mindful that a continuous effortful inhibition of impulses may, over time, be detrimental to their dietary goals if long term change is solely dependent on having self-control.

The literature on coping self-efficacy indicates that having the capabilities to manage challenges or external stressors is important in predicting change [39]. Coping self-efficacy allows individuals to actively approach challenging situations in a positive way and not be over-reliant on self-control [39]. This finding was expressed through dealing with falling off the wagon. Schwarzer and Renner [39] explored the relationship between action self-efficacy and coping self-efficacy. They found that individuals who report higher coping self-efficacy levels also reported better nutrition behaviours [39]. From this, the two psychological constructs of self-control and coping self-efficacy may lend well to each other. Dietitians should consider these constructs when addressing dietary behaviour change as diabetes management often requires a change in lifestyle behaviour and the need for self-regulatory matters like monitoring blood glucose.

Implicit processes

The habitual nature of dietary intake and the relationship between poor dietary intake and health-related illness pose a real challenge to reverse such habits [52]. The types of habits derived from our participants’ narratives have shown consistencies with previous research on food habits associated with T2D which relate to basic eating practices, dining out, meal planning, and carbohydrate/vegetable intake strategies [53]. Previous research on habits in health-related behaviours [52] and physical activity [15] indicates both automatic and conscious processes involved in food-related habits and associated behaviours. Some participants described engaging in some dietary behaviour without conscious thought and therefore, were done automatically. Such automatic behaviour aligns with the idea of habit formation, where a habit is considered “a phenomenon whereby behaviour is prompted automatically by situational cues, as a result of learned cue-behaviour associations” [52]. Some participants acknowledged the need to reverse and ‘unlearn’ these automatic processes to change their diet. Unlearning habits can be an arduous task given the processes involved in creating them [52]. Therefore, unlearning habits requires effortful self-control to practice and monitor behaviour progress from the individual [52]. Dietitians’ dietary advice play an important role in supporting these changes. Dietitians can utilise behaviour change techniques to encourage patients to adopt self-monitoring practices and to prompt rehearsal of alternative behaviours to replace the unwanted habit [54].

The participants discussed limiting the availability of food that is unfavourable for T2D in their home as a way of ‘restructuring their physical environment’ to help influence a positive change in their dietary behaviour. This finding demonstrates the potential importance of using such strategies to create barriers to unwanted behaviour. By reducing exposure to cues of the behaviour, the participants in our study said they could make food choices recommended for T2D. Research suggests it is easier to control one’s behaviour when a less conscious effort is needed [55]. Restructuring the physical environment, for example by limiting the availability of non-recommended food in the house, may make it easier to control the temptation to engage in unwanted behaviour (such as eating chocolate). This restructuring means less conscious effort is required to control the impulse (because there is no readily available chocolate to eat).

While these changes were reported on an individual level, it is important to recognise that there are structural factors that play a role in food choice and dietary intake which are influenced socially and through obesogenic environments [56–58]. Some participants dined out due to convenience and accessibility of restaurants, which supports the literature on the role that environmental cues have on dietary behaviours [56]. Research on food temptations found environmental cues to influence both healthy and unhealthy eating choices [59]. Furthermore, the interplay of portion sizes, the built environment, change in work lives, technology, and food advertising within an ‘obesogenic environment’ [60] can also influence an individuals’ motivation to eat out or choose certain foods regardless of their usual eating behaviours. These findings add to the body of evidence that the control an individual has over their environment may be limited and that the environmental cues play a large role in food choices whether individuals are aware or not [56]. These factors relating to obesogenic environments were only mentioned by one participant and the lack of direct responses around this topic may have been due to the focus of the interview protocol on individual factors. From a sociological perspective, it is important to acknowledge the structural variables that influence individual choice and the interplay with agency. Although not explicitly discussed by the participants, there may be structural limitations affecting their dietary choices that are beyond their awareness or control. Such factors may include financial ability to seek out a dietitian and purchase certain food products, as well as accessibility to services or living conditions [57, 58]. The interplay of agency and structure may be a limitation of the IBC model and future research may wish to consider these limitations when using the model from a behavioural science perspective.

Individual difference factors

Individual difference factors, which distinguish people from one another, such as individuality and personality, were also important in participants’ dietary change [61]. Our study highlighted that the interpersonal style of the dietitian perceived by the participant and their experience of the dietetic consultation had an influence on their motivation to make changes. Our findings are supported by Ball and colleagues [28] that found patients desire more individualised care from their dietitians. Our study’s findings support that of Chen and colleagues [62] that the management of adults with T2D should address physiological, social, and psychological needs as each individual manages their diabetes care through their personal health experiences.

Individual difference factors are vital in providing a patient-centred level of care; therefore, dietitians and other nutrition care providers should be aware of these influential factors when trying to understand an individual’s decision-making and the change process. Research in health interventions and behaviour change techniques has highlighted that the interventionist’s interpersonal style is an important aspect when encouraging behaviour change [23]. However, Hagger and Hardcastle [23] raised an important point that interpersonal styles have not been, yet should be, distinctly included within commonly applied behaviour change technique taxonomies. Although Michie and colleagues [63] distinguished between behaviour change techniques and ‘aspects of the interaction’ that are important for the delivery of behavioural support, our study adds further support to the arguments put forward by Hagger and Hardcastle. Our recent paper on self-enacted dietary behaviour change furthered the literature on behaviour change techniques by closely examining the techniques reported by the same participants of this study [64]. The study found a range of techniques that are important for decision-making processes that should be taken into consideration by dietitians, such as goal setting, problem solving and social support which align with the themes presented in the current paper [64].

Other individual difference factors revealed in the current data related to personality types and inherent traits. Personality dimensions (such as openness, conscientiousness, extraversion, neuroticism, and agreeableness [61]), have been explored to understand whether any associations between personality and dietary intake exist [65]. Research has shown that exhibiting more openness and conscientiousness traits are associated with healthier food intake and compliance with dietary recommendations [65]. It could be suggested that the participants in this study showed some levels of openness and conscientiousness as the majority were receptive of dietary advice, displayed creativity in food preparation, and had goal-directed behaviours to manage their diabetes [66]. These findings emphasise the importance of dietetic consultations being individualised whilst considering personality traits on health behaviours. The personality traits of dietitians have also been explored and indicate that there are notable differences between dietitians and the general public, and dietitians working in different settings [67, 68]. There is an opportunity for future work to explore further the impact of personality trait combinations in patients and dietitians on dietary behaviour change, especially in individual consultations that aim to support healthy eating.

Emotion

Our study also highlighted that adults who receive a T2D diagnosis express emotional responses to their diagnosis and dietetic advice. Some of these emotions are supported by cognitive theories of emotion [69], as it was discussed that the T2D diagnosis itself triggered feelings of shock, guilt, and fear as motivating them to dietary change. These emotions are commonly associated with the emotional reaction of a T2D diagnosis [70]. As discussed above, a T2D diagnosis has been found to be a ‘teachable moment’, triggering cognitive, emotional, and behavioural responses which, in turn, affect decision making [38].

Much of the literature of food and emotion have explored the ways emotion affects eating (increased or decreased intake, cravings, appetite) and triggers for eating (comfort, lack of motivation, stressed, boredom, fear) [71]. These responses were found in some participant narratives who, for example, expressed feelings of ‘nostalgia’ by reminiscing on what they used to enjoy eating however can no longer have, a common emotional association to food [72]. It is perhaps unsurprising that these participants felt a sense of loss and were missing certain foods, as the foods they reported to have removed from their diet, like cake and chocolate, are known to be enjoyed more and with high taste appeal [72].

In regards to understanding the use of emotion for behaviour change, tailoring interventions to elicit an emotional response has been used to promote behaviour change [73]. Although the relationship between emotion on behaviour is well established, and given its influence on cognitive processes [74], there are few theories of behaviour change that incorporate emotion and affective constructs to help explain or predict behaviour [18, 19, 49]. Dietary interventions in the primary care setting are reported to use well-known behaviour change theories and models such as the social cognitive theory, transtheoretical model, and health belief model which tend to focus on the social cognitions and volitional aspects of behaviours [25]. Our study’s findings add to the body of evidence that emotions play an integral part in people’s dietary intake and should be considered in behaviour change models.

Strengths and limitations

Adults with T2D represent cases commonly encountered by dietitians in the primary care setting, and our findings are useful to those delivering nutrition interventions for adults with T2D. The participants in this study represent a population of adults who used early intervention (i.e., seeing a dietitian once newly diagnosed) to manage their diabetes. Many of these participants reported positive outcomes in dietary change, improved glycaemic control, and a better understanding of diabetes. Although the analysis was bound to the theoretical constructs of the IBC model, the model integrates key psychological constructs and processes which allowed for a deeper and more comprehensive understanding of health behaviours [17]. The analysis also allowed for themes to emerge beyond the IBC model. However, these links, including individual differences and emotions, did not come through as strongly in the data than prominent social cognition influences and, therefore, it is important that future research continue to explore these links.

The current study has some limitations. It is important to consider the possible bias in participants’ responses. Although the study recruited n = 21 participants, which may be considered small, it should be noted that through the iterative process of data collection and analysis, the recruitment ceased when data and coding no longer added anything new. The individuals in this study were initially motivated to change their dietary behaviour and were willing to seek dietetic help. We also acknowledge the possibility of social desirability affecting responses. The interviewer was a dietitian, and given this status, participants might have felt a need to answer in a way they deem to be more socially acceptable than would be their ‘true’ response [75]. Future research can explore the lack of mention of financial difficulty amongst the participants, which may reflect a more affluent profile of participants as the study took place in a developed country with a high-income economy. Our data did not capture the processes of assimilating a diabetes diagnosis and how this might change over time for an individual, including how this understanding might impact on their dietary changes and diabetes health outcomes. Further research can explore the stages of understanding a diagnosis and the behaviours experienced by the same person to understand this process.

Finally, this paper presents major themes distinguished by the three processes of the IBC model; however, we acknowledge that many constructs within these processes are interlinked and lend to each other rather than being discrete as presented in this paper. Future research should explore the interconnections and overlap of themes, as well as the exploring whether the interaction between the dietitian and patient may elicit emotional responses. The interplay of agency and structure were not strongly represented in the IBC model which may limit the use of the model from a sociological perspective. As the participants’ mood were not captured in this study, further research could explore the influence that mood and feelings associated with a type 2 diabetes diagnosis has on dietary intake and changes given the literature on emotion and decision making [74]. Our study did not capture the perspectives of young adults. Future research could explore this demographic as it may present different data compared to an older population. Weight stigmatisation and body image were not strongly identified in our participants. Given the known associations with adverse physiological and psychological health outcomes [76], future research can also explore the influence of body image, weight loss and diabetes. The quality of the dietitian consultations was unable to be captured in this study, which presents an avenue for future research that specifically asks questions relating to the quality practice standard outlined by the Academy Quality Management Committee [77].