A systematic review of observational studies exploring the relationship between health and non-weight-centric eating behaviours

.


Introduction
The relationship between body weight and health is complex, (Mauldin, May, & Clifford, 2022;Tylka et al., 2014) and the intricacies need to be considered in healthcare.Factors such as genetics, social determinants of health, mental health, and the impact of weight stigma, weight bias, and health behaviours should be considered, (Matheson, King, & Everett, 2012;Mauldin et al., 2022;Tylka et al., 2014) as opposed to a central focus on an individual's body size.Therefore, a deeper insight into associations between positive health outcomes and eating behaviours that are not centred around weight is crucial to enhance our understanding of how to support health that is free from stigma and harm.
Like weight, eating behaviour is influenced by many factors, including food choice and motivation, dieting, feeding habits and eating difficulties (LaCaille, 2020).Eating behaviour is also subject to internal and external influences on a micro and a macro scale, involving individual, societal, cultural, environmental and economic factors (Emilien et al., 2017;Hanson et al., 2007;LaCaille, 2020;Ogden, 2011).As with other behaviours, these factors can both affect, and be influenced by an individual's health status, (LaCaille, 2020;Ogden, 2011) as well as the care provided by health professionals (Australia, 2015;Hatfield, Withers, & Greaves, 2020).
Health care that is weight focused, or 'weight-centric', particularly for individuals with a higher body weight, may influence eating patterns by encouraging dietary restriction to promote weight loss (Mauldin et al., 2022;O'Reilly et al., 2012).Conversely, health care that is non-weight-centric, that recognises and addresses the multitude of factors that influence health, including genetic, societal, economic, and demographic factors, (Tylka et al., 2014) may encourage changes in health behaviours without dietary restriction (Mauldin et al., 2022).Eating behaviours and approaches that do not centre around weight, may be referred to as weight-neutral (O'Hara et al., 2018), which focus on health, 'not weight-loss', and target process goals and behaviour change as outcomes, rather than weight (Schaefer et al., 2014;O'Hara et al., 2018;Bacon et al., 2011;Tribole et al., 2012).Such eating behaviours may also be referred to as 'innate' (Tribole et al., 2020;Willer, 2013) or 'adaptive' (Schaefer et al., 2014) eating.In dietetics, such approaches favour 'health-centric' over 'weight-centric' practices to support physical and mental health and may include, but are not limited to, the 'non-diet' approach (Willer, 2013), 'intuitive' (Tribole et al., 2012) or 'mindful' eating (Framson et al., 2009), 'health at every size', (Bacon et al., 2005) and eating competence (Satter, 2007) (Supplementary material 1, Table S1).In addition, approaches that do not centralise weight are often weight-inclusive, meaning they focus on improving access to healthcare while reducing weight-stigma, and actively recognise factors that can influence health and well-being (Tylka et al., 2014).
The eating behaviours associated with these approaches often focus on internal regulation to build awareness and trust of internal cues.They promote being present and mindful when eating, recognise the value of enjoying food, gentle nutrition, and encourage flexibility and food diversity (Mauldin et al., 2022).The eating competence model is grounded in biopsychosocial processes, (Satter, 2007) and although not currently defined in this way, all eating behaviours following weight-neutral principles may share such qualities.Lastly, eating behaviours that do not centre around weight, focus on health promotion outside of the motivation or influence to control weight (Tylka et al., 2014).Therefore, for the purpose of this review, these eating behaviours will be referred to as 'health-centric'.
Scientific literature has demonstrated the potential for health-centric eating behaviour to improve and support a range of physical health outcomes and encourage health promoting behaviours (Clifford et al., 2015;Khasteganan et al., 2019;Linardon, Tylka, & Fuller-Tyszkiewicz, 2021;Ulian et al., 2018).Intervention studies have found improved cardiovascular risk factors, including greater reductions in LDL cholesterol when comparing a weight-neutral with a weight-loss group (Bacon et al., 2005;Mensinger et al., 2016).This outcome was sustained for two years, irrespective of weight change (Bacon et al., 2005;Mensinger et al., 2016).Other studies have found improved glycaemic control in people living with diabetes, (Warren, Smith, & Ashwell, 2017) and associations with lower fasting glucose, (de Queiroz et al., 2022) lower odds of inadequate glycaemic control, (Soares et al., 2021) and physical health indicators, including lower cardiovascular risk (de Queiroz et al., 2022;Van Dyke et al., 2022).Associations with measures of body size have also been investigated, where higher levels of health-centric eating behaviours were linked with a lower BMI (Dakin et al., 2023;de Queiroz et al., 2022;Fuentes Artiles et al., 2019;Warren et al., 2017).However, within the context of a weight-neutral approach, weight is recognised as an outcome, and not as a goal or intention of the intervention or eating behaviour (Tylka et al., 2014).Therefore, although weight related outcomes are often embedded within weight-centrism, (Warren et al., 2017) the relationships between body size and 'health-centric' eating behaviours must be considered, due to the influence and impact that a weight-centric society and healthcare system can have on eating behaviour (Mauldin et al., 2022).
In addition to physical health, studies have explored outcomes related to mental health and wellbeing.A study examining intuitive eating behaviours in participants (n = 1491) over an eight year period found a positive association with behavioural and psychological health, including lower odds of depressive symptoms, binge eating and extreme weight control behaviours (Hazzard et al., 2020).Systematic reviews of intervention studies have also identified improved anxiety, and significant improvements in disordered eating, depressive symptoms, and body image (Babbott et al., 2023;Clifford et al., 2015;Schaefer et al., 2014).Additionally, a randomized controlled trial comparing weight-neutral and weight-centric programs, identified significant and sustained improvements in psychological health after a two year follow-up, highlighting the potential for these approaches to support long-term mental health outcomes (Bacon et al., 2005).Further, although not defined as weight-neutral, the SMILES (Supporting the Modification of lifestyle in Lowered Emotional States) trial found an adjunct dietary intervention reduced depressive symptoms irrespective of weight loss, (Jacka et al., 2017) illustrating the potential for a positive mental health impact, independent of weight-related outcomes.There is also a well-established bidirectional relationship between eating behaviour and mental health and wellbeing, (Puccio et al., 2017) highlighting a need to explore psychological health outcomes.
In addition to health outcomes, health-centric eating behaviours have been associated with improvements in health promoting behaviours.A study found increased consumption of fruit and vegetables in those with greater intuitive eating scores (Christoph et al., 2021a) with similar relationships identified for eating competence (Queiroz et al., 2020a).Further, studies have demonstrated the potential for improved health promoting behaviours through a non-weight centric approach, including increased fruit and vegetable intakes, reduced 'ultra-processed' foods, and increased physical activity (Ulian et al., 2018).Another review also found that diet quality was maintained or increased through intuitive eating interventions (Hensley-Hackett, 2022).However, there are inconsistencies across studies, limited by a lack of appropriate measurement of eating behaviour, preventing an interpretation of the effect separate from the intervention (Grider, Douglas, & Raynor, 2021).Consolidated evidence exploring relationships with health behaviours is also limited, and inconsistencies exist in how eating behaviours are defined in the literature (Mantzios, 2021).Regardless, the principles and frameworks associated with these approaches may support health promoting behaviours, (Mantzios, 2021;Rice, Collins, & Health at Every Size®, 2020, pp. 317-347;Satter, 2007;Tribole et al., 2020;Willer, 2013) and further exploration into associations within a range of outcomes is warranted.
Despite existing evidence, to the authors' knowledge, there is no comprehensive review of eating behaviour that prioritise health over weight-centrality, and their relation to health outcomes.As eating behaviour is often measured via self-report questionnaires, (Meule, 2023) it is pivotal to synthesise the existing observational evidence to provide insight into underexplored health outcomes, direct and inform future research, and to provide a comprehensive overview of literature in this fast-evolving field.Therefore, this review aimed to systematically evaluate health-centric eating behaviours reflective of weight-neutral approaches, and their relationship with a) body composition, size and physical health, b) mental health and wellbeing, and c) health promoting behaviours in adults.

Methods
This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was guided by the Cochrane Handbook for Systematic reviews of Interventions for standardised and transparent reporting of methodology and results (Supplementary material 2, Table S1) (Higgins & Green, 2008;Moher et al., 2009).The review was first prospectively registered with The International Prospective Register of Systematic Reviews (PROSPERO) on May 26, 2021 (registration number CRD42021252052), and re-registered as an observational review only on December 1, 2021 (CRD42021288611) due to the scope of evidence.

Search strategy
A systematic search was performed using OVID MEDLINE, OVID M. Eaton et al.EMBASE, PubMed, CINAHL and Web of Science databases on May 12, 2021, to identify peer-reviewed observational and intervention studies that examined 'health-centric' eating behaviours reflective of weightneutral approaches, and a) body composition, size, and physical health, b) mental health and wellbeing, and c) health promoting behaviours in adults.The original search strategy included intervention and observational studies, however, due to the differences in how an eating behaviour was measured and assessed, a decision was made to separate the study into two separate reviews.The present review includes observational studies only.Reference lists of included studies and relevant systematic reviews were manually examined to retrieve relevant studies not captured by the main search.The search strategy reflected the original registered protocol and consisted of key words based on the Participant, Intervention/exposure, Comparator, Outcome (PICO) framework (Supplementary material 3, Table S1).The approaches detailed in Supplementary material 1, Table S1, informed the key words used to identify non-weight-centric eating behaviours, in addition to broad search terms such as "weight-neutral" and "innate eating" to capture eating behaviours unknown to the authors.For the detailed search strategy, see Supplementary material 4.

Eligibility criteria and study selection
Using COVIDENCE (Veritas Health Innovation, 2022) software duplicates were removed, and one reviewer (ME) independently screened all titles and abstracts for eligibility.For studies that met inclusion criteria (Supplementary material 5), full texts records were screened independently by two reviewers (ME and YP).An additional quality assurance check was also undertaken, where title and abstracts were re-searched using keywords, and the list of full text exclusions was re-screened by one reviewer (ME).Discrepancies were resolved by discussions to consensus between the two researchers, and disagreements resolved by a third reviewer (LR).Studies were included if they comprised of human adult populations aged ≥18 years, at least one physical health, body composition or body size outcome, mental health outcome, or health promoting behaviour, and contained at least one validated measure of eating behaviour that reflected or was informed by a weight-neutral approach (Supplementary material 1, Table S1).Observational studies with or without a comparator group were included.Studies were excluded if they comprised of pregnant populations, focussed on infants, children, and adolescents aged <18 years, were validation studies, or utilised a non-validated measure or tool to assess the exposure.Reasons for exclusion can be found in Supplementary material 6.

Data extraction
Quantitative data were systematically extracted utilising a template guided by each outcome domain (Table 1).Data extraction was performed independently by one reviewer (ME) in consultation with the authorship team, and a data extraction quality assurance check of all studies was conducted independently by a second reviewer (JM) (Houston, Probst, & Humphries, 2015).Data extracted included information relating to study details (author, year, country), study overview (study design, setting, data source, follow up), population characteristics (sample size, sex, age, ethnicity, sample type, comorbidities), and exposure (exposure type, measurement tool, mean for total score and subscales, comparator).
Data extracted in relation to study outcomes included the measurement tools used, baseline mean score and/or outcome prevalence, mean exposure in outcome groups and/or mean outcome in exposure group, association (including correlations and regression) and descriptive interpretation of results.Corresponding authors of studies were contacted via email to resolve inconsistencies with the study population (ie.age of participants included in the analysis) and to obtain missing data.If the author did not reply and no other outcomes fulfilled the inclusion criteria, the study was excluded (with n = 5 excluded due to the inclusion of participants aged <18 years).(Avalos et al., 2006;Durukan et al., 2019;Kerin, Webb, & Zimmer-Gembeck, 2019;Richard et al., 2019;Tylka et al., 2006).
It was a requirement that studies include a validated measure (Ginty, 2020) of eating behaviour (eg. the Intuitive Eating Scale) (Tylka et al., 2013) to allow for comparison between studies and ensure validity of the eating behaviours explored.However, for health outcomes, we included both validated (Ginty, 2020) (eg.Binge Eating Scale) (Duarte, Pinto-Gouveia, & Ferreira, 2015) and non-validated measures (eg.'In the past year, have you ever eaten so much food in a short period of time that you would be embarrassed if others saw you (binge eating)?') (Denny et al., 2013), in an attempt to limit missing data due to confirmation bias.

Risk of bias
Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) adapted for cross-sectional studies, (Herzog et al., 2013;Modesti et al

2016
) with additional questions tailored to the review (See Supplementary Material 7).The tool utilises a star system to appraise the quality of each study against three domains: selection, size and response rate and ascertainment of the exposure (5 stars), the comparability of the sample (2 stars), and assessment and analysis of the study outcome (3 stars).A score of 0-4 or 5-6 suggests an unsatisfactory and satisfactory study, respectively, and a score of 7-8 or 9-10 suggests a good or very good study.The maximum score was ten.Studies were appraised independently by two reviewers (TF and ME), and discrepancies were rectified through discussion with a third senior reviewer (YP).A quality assessment was completed for all independent studies, to allow for an accurate assessment of quality.A sensitivity check was conducted by excluding studies rated as 'unsatisfactory' from the analysis of outcomes.

Data analysis
Data were categorised into four outcome domains (Table 1).In brief, any outcome related to an individual's body composition, size and physical health was categorised into domain one.Outcomes related to mental health and wellbeing were categorised in domain two, including both mental health diagnoses, and factors that influence a person's mental wellbeing such as mental health symptomology, quality of life, eating disorder risk and body image.Outcomes that encompassed behaviours that promote health, such as dietary intake and physical activity were categorised into domain three.Dietary intake was further organised into food groups and key nutrients for comparability between studies.The fourth domain included: a) any measures of eating behaviours that may impact health, or that did not reflect a weight-neutral approach (ie.outside of a 'weight-neutral'/'non-weight centric' context); and b) behaviours that did not fit into domains two or three.Measures of disordered eating were originally categorised as domain four, however, an overlap in measures between domain two and four highlighted inconsistencies in the terms used across studies to describe the same measure (eg "eating disorder risk" vs "disordered eating").Disordered eating behaviours were, therefore, represented under domain two.Studies were qualitatively synthesised (Campbell et al., 2020) under each domain and reported in a summary table.Outcomes reported as p < 0.05 were considered significant for comparability between studies.

Identifying common themes across measures of eating behaviour
Similarities between the validated tools used to measure each eating behaviour were explored.Each tool was identified and grouped into related eating behaviours.If multiple versions of the tool were identified, they were characterised into an overarching category for the health outcome analysis.The subscales of tools were collated, and definitions were sourced from the referenced validation paper.Key terms were extracted from each definition and definitions were applied to the biopsychosocial model to highlight common themes across eating behaviours.

Study selection
A total of 8258 records were identified, with an additional 18 records identified by manual search of reference lists of relevant systematic reviews.After removal of duplicates, 86 articles met the inclusion criteria.The review identified several studies from common datasets.If multiple studies utilised a common dataset, and the same exposure was analysed, they were considered as one study.The study with the largest sample was considered the primary study, with the exception of three studies (Köse et al., 2019;Quick et al., 2015;Winkens et al., 2020) that contained more analyses related to outcomes of this review.Refer to Supplementary material 8, Table S1 for all studies that presented a common dataset.Of the included studies, 75 unique datasets (studies) are included.Three studies (Järvelä-Reijonen et al., 2016;Rodgers, White, & Berry, 2021;Özkan et al., 2021) also presented data for multiple exposures, with six unique exposures reported; treated as unique datasets (studies, n = 78) for the descriptive analysis of this review.The full selection process can be found in the PRISMA flow diagram (Fig. 1).

Participant characteristics
The 75 included primary studies included 94,710 individuals, with an analytic sample size ranging from 32 to 52,163 participants (median: 293) across all primary datasets.Sixty-nine (92%) studies were conducted with community samples, four (5.3%) with outpatients, and two (2.7%) in a combined inpatient and outpatient sample.Of these, over one-third (40%, n = 30) consisted of university student populations only.Twenty-six studies (35%) reported female populations only, with an average of 78% females across all studies.No studies reported on gender diverse populations.Age was provided in sixty-eight (90.7%) studies, and ranged from 18 to 67.5 years, with a pooled mean of 32.4 (±6.7) years across all primary studies.Forty (53.3%) studies reported participant ethnicity, with Caucasian populations the most reported ethnic percentage (pooled mean ~72.5%) across 36 studies (Supplementary material 9, Table S1).
M. Eaton et al.Fig. 2. Summary of key outcomes for included studies, including the direction of relationship and the number of studies exploring the relationship.Footnotes ↑: higher/greater levels ↓: less/lower levels.Solid line: relationships where the majority of studies presented a statistically significant relationship in the direction shown Broken line: relationships where the majority of studies presented a relationship in the direction shown but were not statistically significant.Where BMI reflects n studies, and mental health and wellbeing and health promoting behaviours reflect outcomes; Blue line: relationships with ≥25 studies or outcomes Green line: relationships with between 10 and 25 studies or outcomes Purple line: relationships with between 5 and 10 studies or outcomes Red line: relationships with <5 studies or outcomes × Body image includes body image, body image acceptance, body appreciation, body satisfaction, body awareness, body image concern, body dissatisfaction, body checking, weight-related guilt and shame and perceived acceptance of body shape and weight **Disordered eating/eating disorder (DE/ED) risk includes specific measures of DE/ED risk, as well as orthorexia, binge eating, emotional eating, rigid and flexible control, dieting, and unhealthy and extreme weight control behaviours.Physical health outcomes represent outcomes for 'body composition, size and physical health'.

BMI
Fifty (89.3%) of 56 studies explored a relationship between BMI and the total score of each health-centric eating behaviour.Of these, 33 (66%) studies found greater intuitive eating, mindful eating, and eating competence were significantly related to a lower BMI (Fig. 2), with effect sizes ranging from small (eg.β = − 0.02, p < 0.001 (Smith et al., 2020)) to large (eg.r = − 0.576, p < 0.001 (Hawks et al., 2005)) (Supplementary material 11, Table S1).An additional four (8%) studies (Augustus-Horvath et al., 2011;Hootman et al., 2018;Özkan et al., 2021) found the same statistically significant relationship but only in those aged 26-39 and 40-65 years, (Augustus-Horvath et al., 2011), males only, (Hootman et al., 2018) or females only ( Özkan et al., 2021) (for intuitive and mindful eating).Of the studies that did not find statistical significance, the same pattern of relationships followed across 11 (22%) studies.Three (6%) of the 50 studies explored baseline associations with changes over time.Of these, one study (Christoph et al., 2021b) found a statistically significant difference between intuitive and non-intuitive eaters, where fewer intuitive eaters had BMI ≥25 or ≥30 kg/m 2 at a five year follow up.Another study (Webb et al., 2013) found higher intuitive eating at a four month follow up was significantly associated with lower BMI at baseline.The same study also found significantly lower levels of intuitive eating in those who experienced an increase in BMI over time.

Disordered eating and eating disorders
Thirty-three outcomes across 23 studies explored a relationship between broad measures of disordered eating and eating disorder risk and the total score of each health-centric eating behaviour.This included eating disorder risk and disordered eating, as well as binge eating, emotional eating, orthorexia behaviours, dieting, and unhealthy weight control behaviours.Of these, 25 of 33 (75.8%) outcomes found greater intuitive and mindful eating were significantly related to lower disordered eating behaviours and eating disorder risk (Fig. 2), with effect sizes ranging from small (eg.β = − 0.014, p < 0.001 (Lee, Williams, & Burke, 2020)) to large (eg.r = − 0.69, p < 0.001 (Craven et al., 2019)) (Supplementary material 11, Table S1).No studies explored relationships with eating competence.Of the outcomes that did not reach statistical significance, the same pattern of relationship was followed across four (12.1%) of the remaining outcomes.In addition, five disordered eating outcomes across two studies (Christoph et al., 2021b;Hazzard et al., 2020) explored change over time, where one study found significantly fewer intuitive eaters compared to non-intuitive eaters, engaged in binge eating with loss of control, dieting and unhealthy weight control behaviours at a fiveyear follow-up (Christoph et al., 2021b).Further, another study found both higher intuitive eating at baseline and increased intuitive eating between baseline and follow up (eight years) were associated with a significantly lower odds (92% and 86% respectively) of binge eating at the follow up (Hazzard et al., 2020).

Mental health
Fifteen outcomes across ten studies explored a relationship between measures of mental health and the total score of each health-centric eating behaviour.This included symptoms of depression, anxiety, stress, and overall mood.Of these, five of seven (71.4%) outcomes found greater intuitive (Carrard et al., 2021;Iannantuono et al., 2012;Robinson et al., 2021) and mindful eating (Finger, de Freitas, & Oliveira, 2020;Giannopoulou et al., 2020) were significantly associated with lower levels of depressive symptoms (Fig. 2), with effect sizes ranging from small (eg.r = − 0.17, p < 0.05 (Giannopoulou et al., 2020)) to moderate (eg.r = − 0.38 p < 0.01 (Carrard et al., 2021)) (Supplementary material 11, Table S1).Another (n = 1, 14.3%) study (Lee et al., 2020) also found a significant association between greater intuitive eating and lower depressive symptoms, after controlling for relevant confounders including BMI and body image (β 0.004, p < 0.05 (Lee et al., 2020)).No studies investigated relationships with clinical depression or eating competence.In addition, two studies (Hazzard et al., 2020;Winkens et al., 2020) explored change over time.One study (Winkens et al., 2020) explored subscales only, and the other (Hazzard et al., 2020) found higher intuitive eating was related to lower depressive symptoms at an eight year follow up, however, the finding was not statistically significant.Lastly, four outcomes across four studies (Finger et al., 2020;Järvelä-Reijonen et al., 2016;Robinson et al., 2021) explored stress, where higher intuitive eating, mindful eating and eating competence were significantly related to lower stress across all studies.No studies found a statistically significant relationship between anxiety and each exposure, however, all three studies (Finger et al., 2020;Herbert et al., 2013;Robinson et al., 2021) found greater intuitive and mindful eating was related to lower levels of anxiety.

Dietary quality
Eight outcomes across eight studies explored dietary quality and the relationship between the total score of each health-centric eating behaviour.Of these, half (n = 4, 50%) of the outcomes found greater intuitive eating, mindful eating, and eating competence were significantly related to greater diet quality (Fig. 2) (Atalay et al., 2020;Choi et al., 2020;Lohse et al., 2010), with effect sizes ranging from moderately small (eg.r = 0.230, p = 0.001 (Choi et al., 2020)) to large (eg.r = 0.636, p < 0.01 (Atalay et al., 2020)) (Supplementary material 11, Table S1).Of those that did not reach statistical significance, one (12.5%)study (Lohse et al., 2012) found greater dietary quality in the eating competent group when compared to a non-eating competent group.Two outcomes found an opposing relationship, where lower dietary quality was associated with higher intuitive eating.However, this was found in male participants only in one (n = 1, 12.5%) outcome, (Horwath et al., 2019) and was not statistically significant in the other (n = 1, 12.5%).(Jacob et al., 2020).In addition, a statistically significant association was found for single outcomes of dietary adequacy (β = 0.098, p = 0.049) (Bilici et al., 2018) and diversity (r = 0.137, p = 0.019), (Smith et al., 2006) where greater adequacy and diversity were associated with greater intuitive eating.

Other health promoting behaviours
Greater mindful eating was significantly associated with a more 'health promoting lifestyle' (r = 0.274, p = 0.000), (Köse et al., 2019) as well as a tendency to consume smaller serving size of energy dense foods (r = − 0.36, p < 0.05; β = − 0.31, p < 0.05) (Beshara et al., 2013).One study (Smith et al., 2006) also found greater intuitive eating was significantly associated with higher levels of pleasure associated with food and eating (r = 0.484, p < 0.001), and lower 'health consideration' in food choices and eating habits (r = − 0.209, p < 0.001; eg. the amount of fat or calories n food).Lastly, ten sleep outcomes were explored across two studies (Quick et al., 2015;Tilles-Tirkkonen et al., 2019), where 70% (n = 7) of outcomes were significantly related to better sleep and sleep quality in groups that were eating competent (Fig. 2).No studies explored change over time for health promoting behaviour outcomes.

Other eating behaviours outcomes
Eight (10.7%) of the 75 studies explored other eating behaviour outcomes.Of these, eight outcomes were investigated, with only two studies exploring the same measure.Both studies (Keyte et al., 2020;Mantzios et al., 2018b) found greater mindful eating was significantly associated with a lower motivation to eat 'unhealthy foods' for reasons outside of hunger, with moderately large effect sizes (r = − 0.47, p < 0.001; r = − 0.47, p < 0.01).No studies provided associations with eating competence (Supplementary material 11, Table S1).

Study critical appraisal (risk of bias)
For the studies that contained an overlapping dataset (Supplementary material 8, Table S1), a quality assessment was completed for all independent studies (n = 86).Overall, 73% (n = 63) of studies were considered good (n = 27, 31%), or satisfactory (n = 36, 42%) quality.A further three studies (3%) were considered very good, and 20 studies (23%) were considered unsatisfactory quality (Supplementary material 12, Table S1).For those considered unsatisfactory, most did not follow appropriate recruitment methods, control for relevant confounders, or clearly describe and report statistical analyses.Further, no studies included a justified or satisfactory sample size, or addressed nonrespondents.Across all studies, the lowest ratings were for the following criterion: representativeness of the sample, the sample size and addressing non-respondents.All studies included a validated ascertainment of the exposure (eating behaviour), as this was a requirement of inclusion.The sensitivity check of studies rated as 'unsatisfactory' did not reveal any discrepancies in the direction or significance of outcomes.However, mindfulness and self-compassion outcomes included a majority of studies carrying a high risk of bias.

Discussion
This review aimed to provide insights into 'health-centric' eating behaviours that do not centre around body weight, and their relationship with a) body composition, size and physical health, b) mental health and wellbeing, and c) health promoting behaviours in adults.Our results identified such eating behaviours were associated with a broad range of positive health outcomes and greater engagement in health promoting behaviours.Specifically, greater levels of 'health-centric' eating behaviour including intuitive eating, mindful eating or eating competence were significantly related to three outcome patterns including 1) lower BMI and other measures of body composition; 2) lower levels of disordered eating, depressive symptoms, and stress, as well as greater body image, mindfulness, and self-compassion; and 3) higher fruit and vegetable intake, greater dietary quality, greater physical activity, and better sleep (Fig. 2).Higher levels of each eating behaviour also displayed potentially clinically significant patterns including lower cholesterol (total and LDL), lower triglycerides, and lower anxiety.These findings help to enhance our understanding of the health outcomes and behaviours associated with eating behaviours that do not centre around body weight and weight loss.In addition to positive health outcomes, this review also identified a need for greater study population diversity.There were no studies with gender diverse populations, with the majority in community samples (n = 69, 92%), university/college students (n = 30, 40%), Caucasian (pooled mean ~72,5%), and female (pooled mean 78%) populations.

Health-centric eating behaviours
Intuitive eating (n = 48) was the most studied eating behaviour, followed by mindful eating (n = 19), and then eating competence (n = 11).This identified a gap in the current literature, where no studies explored the relationship between mindful eating and physical health (eg.measures of cholesterol), three studies (n = 4 outcomes) (Clifford et al., 2010;Järvelä-Reijonen et al., 2016;Rodgers et al., 2021) explored relationships between eating competence and mental health and wellbeing, and limited studies (n = 6 studies, n = 7 outcomes) (Beshara et al., 2013;Choi et al., 2020;Köse et al., 2019;Mantzios et al., 2018a;Moor et al., 2013;Winkens et al., 2020) explored relationships between mindful eating and health promoting behaviours.Importantly, there were also inconsistencies between the scales and measures of mindful eating, including four different measurement tools (MEQ, MEQ-Turkish, MES, MEBS) with differing subscales (Supplementary material 10, Table S1).Inconsistencies were also identified with regards to the characterization and labelling of disordered eating outcomes, where different measures, tools and terminology were used interchangeably across all studies.It would be advisable for future research to combine, assess, and validate one measure of mindful eating, as well as establish a coherent and accepted definition for 'disordered eating' and 'eating disorder risk'.This will allow for more consistent and standardised reporting of eating behaviour, while supporting more robust findings and advancements.
In addition, although eating competence is grounded in biopsychosocial processes, (Satter, 2007) the results of this review suggest the biopsychosocial model is foundational to all 'health-centric' eating behaviours (Supplementary material 10, Table S1).This is an important consideration, as biopsychosocial factors such as genetics, physical ailments, weight-stigma, self-esteem, and one's social environment and personal relationships, can be used to inform safe and health-supportive eating behaviour.However, the model's application focuses greatly on their influence over health and eating behaviour, (Lehman, David, & Gruber, 2017;McCabe et al., 2023) and is frequently viewed through a weight-centric lens (Rubino, 2019, pp. 325-359).Therefore, we propose that such eating behaviours are not only influenced by, but consider, apply, and accept the biopsychosocial model as core components within the eating behaviour frameworks.Therefore, future research may characterise, label and explore such eating behaviours within this model to better capture eating in a way that is not centred around weight.Further, this review also identified the lack of a coherent definition for eating behaviours that are non-weight-centric.As a result, it may also be advisable for researchers to refer to the eating behaviours as 'health-centric' as demonstrated in this review.This will allow for more standardised reporting of eating behaviours that are non-weight-centric.

Body composition, size, and physical health outcomes
When considering body composition, body size, and physical health, a consistent statistically significant finding was observed, where a lower BMI, weight, waist circumference, body fat percentage and waist-toheight ratio were related to higher levels of all 'health-centric' eating behaviours.However, the relationship between weight and health is complex, (Mauldin et al., 2022;Tylka et al., 2014) and the intricacies of the relationship must be considered.Although intervention studies exploring the effectiveness of eating competence based interventions are limited, substantial literature supports a potential causal pathway between intuitive and mindful eating.(Fuentes Artiles et al., 2019).However, our findings may also be explained by weight stigma and the societal and systemic pressures for individuals living in larger bodies to lose weight (Mauldin et al., 2022;Mensinger, Tylka, & Calamari, 2018;Puhl et al., 2009).These internal and external pressures may promote and encourage eating behaviour that could be in contradiction with the eating behaviours of this review, such as restrictive, disordered, inflexible eating, which our review also found were inversely associated with each exposure.Equally, individuals living in smaller bodies may experience less societal pressure to diet and are, therefore, less likely to exhibit weight control behaviours, (Malinauskas et al., 2006) resulting in a potentially higher score on the validated tools explored in our review.Further, substantial evidence has identified dieting and weight control behaviours can result in a weight increase over time, (Lowe et al., 2013;National Health & Medical Research Council, 2013) which may further help to explain our findings.
Our review also identified high variability when exploring relationships between 'health-centric' eating behaviour and other measures of physical health.However, although not statistically significant, higher HDL cholesterol, lower total and LDL cholesterol and lower triglycerides were related to greater eating competence and intuitive eating.This finding is of clinical significance, and may be explained by a potentially causal pathway (Bacon et al., 2005;Mensinger et al., 2016).It may also be explained by associated health promoting behaviours, such as higher fruit and vegetable intake, (Toh, Koh, & Kim, 2020) which our review also identified.Other physical health measures varied, including blood glucose and blood pressure, and although not statistically significant, may be of clinical relevance, where most outcomes were supportive of health (ie.lower blood pressure) suggesting that the eating behaviours are not health hindering.The variability of the findings may be partly explained by unreliable measures, (Ikeda et al., 2019;Jones et al., 2003), or 94% of included studies being community samples, and not a clinical cohort.Similar variability in outcome measures have been found across intervention studies, (Hayashi et al., 2021) which conversely, may suggest an absence of a casual association.
Despite the complexity, these findings contribute to a growing body of literature in support of a health-centric approach to health.Understanding the direction and strength of such relationships may support health professionals, like dietitians, in clinical practice.The understanding of these associations may encourage the exploration of one's relationship with food and how this impacts health, rather than fixating on weight status.As a result, these findings may suggest potential benefits in screening and assessing eating behaviour using the validated tools explored in this review.Future studies should explore these associations by unpacking the mediating factors and any causal relationships seen in intervention and longitudinal research.

Mental wellbeing outcomes
When considering mental wellbeing, higher levels of intuitive and mindful eating were significantly related to lower levels of disordered eating and eating disorder risk, along with greater body image across most of the studies included.This was an expected finding, where disordered eating behaviours, such as binge eating, unhealthy or extreme weight control and emotional eating, are in contradiction with the flexible, health-focused and unrestrained eating behaviours promoted by intuitive eating (Tribole et al., 2020).Intervention studies support the relationship between intuitive eating and disordered eating via a potential causal pathway, where the application of 'health-centric' approaches, such as intuitive eating, have resulted in reduced disordered eating behaviours and increased body image (Babbott et al., 2023;Schaefer et al., 2014).Additionally, although limited to two studies, (Christoph et al., 2021b;Hazzard et al., 2020) greater intuitive eating was also associated with long-term outcomes, including significantly less binge eating, and lower engagement in dieting and weight control behaviours such as fasting and skipping meals.This signifies the potential for intuitive eating to predict positive health outcomes in the long term.However, while more longitudinal research across all eating behaviours is needed, these findings may support the use of validated tools of 'health-centric' eating behaviour in clinical settings.This may be of importance to dietitians, where tools can be used to identify behaviours that may need additional support or to support the screening of concerning and health hindering eating behaviours.
Other mental health and well-being outcomes were consistent with the above findings, where higher levels of 'health-centric' eating behaviours were significantly related to lower levels of depressive symptoms and stress, as well as greater mindfulness and self-compassion across many studies.However, most outcomes reflected intuitive eating, with only one exploring eating competence (with stress) (Järvelä-Reijonen et al., 2016).Additionally greater intuitive eating was also related to lower levels of anxiety, (Finger et al., 2020;Herbert et al., 2013;Robinson et al., 2021) which may be of clinical significance due to the influence that mental health conditions can have over eating behaviours.These associations may be partially explained by bidirectional relationships between eating behaviour and mental health and wellbeing, including depression, (Firth et al., 2019;Jacka et al., 2017;Puccio et al., 2016Puccio et al., , 2017) ) anxiety, (Devonport, Nicholls, & Fullerton, 2019;Puccio et al., 2016) stress (Tomiyama et al., 2010;Yau et al., 2013), mindfulness (Ouwens et al., 2015;Pidgeon, Lacota, & Champion, 2013) and self-compassion (Braun et al., 2021;Breines et al., 2014).They may also influence eating behaviours indirectly through nutrition impact symptoms such as appetite, (Engel et al., 2011;Yau et al., 2013) and medication side effects.(Werneke, Taylor, & Sanders, 2013).Therefore, a complex interaction exists between eating behaviours and mental health and wellbeing, and a deeper exploration of mediating factors is needed.Consistent with other findings, these relationships may be explained by a causal pathway, where interventions that promote eating by internal cues improve psychological health, including depression, self-esteem, anxiety, and general wellbeing (Schaefer et al., 2014).Additionally, this review also identified evidence that supports positive long-term outcomes, where greater intuitive eating was related to mindfulness (Webb et al., 2013) and depressive symptoms (Hazzard et al., 2020), however, more longitudinal research is needed.Regardless, understanding this relationship strengthens our understanding between health-centric eating behaviours and mental health, and may support a health-centric focus within mental health care.

Health promoting behaviours outcomes
Greater 'health-centric' eating behaviour was significantly related to a range of healthful diet related behaviours, including higher fruit and vegetable intake and greater diet quality.However, the relationships were mostly found with intuitive eating and eating competence.Further, the philosophy and framework of such eating behaviours may explain this association, where focus and attention is placed on flexible eating, gentle nutrition, finding enjoyment in food and eating, and building awareness and trust in internal cues (Satter, 2007;Tribole et al., 2020).Components may work together to support healthful dietary patterns and directly influence diet quality, with findings from intervention studies supporting this assumption (Hensley-Hackett, 2022).Other interventions following similar principles have also found improved fruit and vegetable intakes (Greene et al., 2012;Mensinger et al., 2016), although causal effects of eating competence are limited.
Despite some significant relationships, there was variability across other dietary intake outcomes.This may result from heterogeneity across studies, where foods were measured, characterised, and labelled differently.It may also relate to dietary data collection methods, where the majority of studies used a 24-h recall or food frequency questionnaire (Supplementary material 11, Table S1), limited by participant memory, seasonal variability, within person variation, preciseness and participant health literacy and burden (Bailey, 2021).As a result, further research is needed to unpack potential mediating and causal relationships between such factors.
In addition to diet related outcomes, this review also identified a positive association between greater intuitive eating and eating competence and physical activity.Previous research has identified a potential causal pathway, where interventions incorporating intuitive eating and eating competent components increased physical activity levels (Greene et al., 2012;Mensinger et al., 2016).Of note, interventions targeting physical activity are limited.However, similar to dietary intake, the relationship may be explained by the philosophies of such approaches that promote life-enhancing movement that focuses on how the body feels, rather than external motivators (Satter, 2007;Tribole et al., 2020).These principles also help explain the finding where lower appearance and weight related exercise motivations were significantly associated with greater intuitive eating.Further to this, greater eating competence was also related to greater sleep quality, sleep duration, and less smoking.These findings may be explained by other outcomes explored above, where lower levels of stress and higher levels of mindfulness may support better sleep and less smoking (Cambron et al., 2020;Kalmbach, Anderson, & Drake, 2018;Rusch et al., 2019).However, due to the impact sleep and smoking can have on appetite, (Chao et al., 2019;Lin et al., 2020) the relationship may also be explained by components of eating competence such as regular eating.Although, due to the limited studies these results must be interpreted with caution.
Importantly, the relationships detailed above suggest 'health-centric' eating behaviours can be health supportive, not health hindering.Health professionals, like dietitians, may be able to direct the focus to their client's eating behaviour to support the engagement of health promoting behaviours, independent of weight.However, once again, further research is needed to better unpack these relationships.

Limitations
The broad range of health outcomes and eating behaviours explored in this review serve as a base for future studies exploring health-centric eating behaviours.However, several limitations should be considered.Firstly, many studies included explored cross-sectional associations only, therefore, causality cannot be inferred.Future research should focus on intervention studies to establish causality, longitudinal studies to understand changes over time, and investigate the mechanisms at action, to decipher whether reverse causality is at play.Secondly, the quality analysis indicated that 23% of studies carried a high risk of bias.Despite the sensitivity check revealing minimal influence on the outcomes presented, this highlights the need for further high-quality studies.Greater diversity across study populations is needed to understand the relationships across more diverse groups.Additionally, exploring subscales would provide further insight into relationships between health outcomes and specific components of eating behaviours.
Further, as the final search for this review was completed in May 2021, we are aware of the potential for new studies and developments to have emerged from this fast-evolving field since then.However, the general consistency observed across the 86 studies provides confidence that our findings remain as a comprehensive overview of this large body of work.Therefore, the groundwork of this review remains informative while also providing the foundation for future exploration of how such eating behaviours influence health outcomes, with broad significance to both academic research and future clinical/public health initiatives.Lastly, eating behaviours that do not centre around weight were grouped together in this review to investigate their associations with a range of health outcomes.However, variation between scales and within eating behaviours must be acknowledged.The gaps in the literature related to mindful eating and eating competence also prevented comparison across different eating behaviours for most outcomes, and many of the relationships identified in this review were pertaining more heavily to intuitive eating.

Conclusion
This review contributes to a fast evolving field, providing an overview of the direction, strength, and significance of health outcomes and how they relate to 'health-centric' eating behaviours that do not centre around body weight.The identified eating behaviours, including intuitive eating, mindful eating and eating competence, were significantly related to a broad range of positive health outcomes and engagement in health-promoting behaviours.In support of the biopsychosocial model, these findings provide consolidated evidence in support of eating behaviours that do not centre around body weight.They also provide further support for the usefulness of health-centric eating behaviour in healthcare, in addition to identifying relationships with health outcomes to help direct future investigation, where more high-quality research is needed.

Ethical statement
N/a.