Overcoming Barriers in Eating Disorder Care: Advances, Gaps, and Recommendations for Equitable Assessment and Treatment.

This paper provides an overview of topics discussed by clinicians and researchers invited to speak at the Canadian Nutrition Society's Thematic Conference 2023, which was centered on advances in research and practice in the assessment and treatment of disordered eating and eating disorders. Presenters emphasized the importance of understanding how systemic factors such as racism, weight stigma, and COVID-19 affect the assessment and treatment of eating disorders, and proposed strategies for addressing these inequities. In this paper, we provide actionable recommendations for clinicians working with individuals with eating disorders; professional development, cultural competence, and equitable assessment and treatment practices are discussed.

Adaptable reservoir computing: A paradigm for model-free data-driven prediction of critical transitions in nonlinear dynamical systems.

A problem in nonlinear and complex dynamical systems with broad applications is forecasting the occurrence of a critical transition based solely on data without knowledge about the system equations. When such a transition leads to system collapse, as often is the case, all the available data are from the pre-critical regime where the system still functions normally, making the prediction problem challenging. In recent years, a machine-learning based approach tailored to solving this difficult prediction problem, adaptable reservoir computing, has been articulated. This Perspective introduces the basics of this machine-learning scheme and describes representative results. The general setting is that the system dynamics live on a normal attractor with oscillatory dynamics at the present time and, as a bifurcation parameter changes into the future, a critical transition can occur after which the system switches to a completely different attractor, signifying system collapse. To predict a critical transition, it is essential that the reservoir computer not only learns the dynamical "climate" of the system of interest at some specific parameter value but, more importantly, discovers how the system dynamics changes with the bifurcation parameter. It is demonstrated that this capability can be endowed into the machine through a training process with time series from a small number of distinct, pre-critical parameter values, thereby enabling accurate and reliable prediction of the catastrophic critical transition. Three applications are presented: predicting crisis, forecasting amplitude death, and creating digital twins of nonlinear dynamical systems. Limitations and future perspectives are discussed.

Rate-induced tipping in complex high-dimensional ecological networks.

In an ecosystem, environmental changes as a result of natural and human processes can cause some key parameters of the system to change with time. Depending on how fast such a parameter changes, a tipping point can occur. Existing works on rate-induced tipping, or R-tipping, offered a theoretical way to study this phenomenon but from a local dynamical point of view, revealing, e.g., the existence of a critical rate for some specific initial condition above which a tipping point will occur. As ecosystems are subject to constant disturbances and can drift away from their equilibrium point, it is necessary to study R-tipping from a global perspective in terms of the initial conditions in the entire relevant phase space region. In particular, we introduce the notion of the probability of R-tipping defined for initial conditions taken from the whole relevant phase space. Using a number of real-world, complex mutualistic networks as a paradigm, we find a scaling law between this probability and the rate of parameter change and provide a geometric theory to explain the law. The real-world implication is that even a slow parameter change can lead to a system collapse with catastrophic consequences. In fact, to mitigate the environmental changes by merely slowing down the parameter drift may not always be effective: Only when the rate of parameter change is reduced to practically zero would the tipping be avoided. Our global dynamics approach offers a more complete and physically meaningful way to understand the important phenomenon of R-tipping.

Impact of a Web-Based Nutrition Intervention on Eating Behaviors and Body Size Preoccupations among Adolescents.

We aimed to evaluate the impact of a web-based school nutrition intervention on eating behavior traits, body weight concern, body size perception and body size dissatisfaction in adolescents. Ten classes of secondary students in Canada (13.6 ± 0.8 years) were randomized into an intervention (n = 162 students) or control group (n = 75 students). Adolescents in the intervention, conducted between 2011 and 2013, participated in an online nutrition challenge to increase their consumption of vegetables, fruits and dairy products using a web-based platform over six weeks. Measurements were taken at baseline (PRE) and post-intervention (POST). No significant negative changes were observed between the intervention and control groups for eating behavior traits, body weight concern, body size perception and dissatisfaction. However, results suggest a trend for a positive effect of the intervention on susceptibility to hunger in boys (group × time interaction, p = 0.10). Specifically, boys experienced a reduction in their susceptibility to hunger in response to the intervention (PRE: 6.1 ± 3.8, POST: 4.8 ± 3.7, p = 0.009). An intervention aimed at improving the eating habits of adolescents did not negatively influence body size preoccupations. In response to the intervention, boys tended to show a lower susceptibility to hunger, which might help them to prevent overeating and adopt healthy eating habits.

Body Image and Lifestyle Behaviors in High School Adolescents.

This secondary data analysis study aimed to examine the associations between 1) body size perception (BSP) and body size dissatisfaction (BSD) and 2) lifestyle behaviors and BSP and BSD in adolescents. The study pooled cross-sectional data from two studies (n = 301) performed in adolescents. Weight and height were measured, while lifestyle behaviors and perceived actual and desired body size variables were self-reported. Linear regression analysis assessed the contribution of sex and zBMI to BSP and BSD scores. Pearson's correlation explored associations between BSP and BSD. Cohen's effect sizes compared satisfied and dissatisfied adolescents within the underestimators subgroup. A positive association between BSP and BSD scores was observed among girls living with normal-weight and overweight/obesity only (r = 0.26; p ≤ 0.001 and r = 0.38; p < 0.05, respectively). Underestimators who were satisfied with their body size showed a moderate effect size for a lower zBMI, a small effect size for lower screen time, and higher sleep duration compared to dissatisfied underestimators. Underestimation was associated with more body size satisfaction in adolescent girls with normal weight and overweight/obesity, suggesting a protective effect of underestimation. These findings support the hypothesis that body size satisfaction and underestimation in adolescents is associated with healthier lifestyle behaviors.

Associations of timing of food intake with energy intake, eating behaviour traits and psychosocial factors in adults with overweight and obesity.

Introduction: Whether a late distribution of food intake impacts obesity through increased energy intake remains uncertain and the behavioural characterization of late eating needs to be further investigated. The first objective of this study was to assess the associations between late eating and body mass index (BMI) and total energy intake (TEI), and whether TEI mediates the association between late eating and BMI. The second objective was to assess the associations between late eating and eating behaviour traits or psychosocial factors and whether eating behaviour traits mediate the association between late eating and TEI. Methods: Baseline data from 301 individuals (56% women, age = 38.7 ± 8.5 years; BMI = 33.2 ± 3.4 kg/m2), who participated in four weight loss studies were used in this cross-sectional study. Total energy intake was assessed using a three-day food record from which the percentage of TEI after 17:00 and after 20:00 was calculated. Eating behaviour traits and psychosocial factors were assessed with questionnaires. Pearson correlations and mediation analyses adjusted for age, sex, underreporting of energy intake, sleep duration and bedtime were performed. Results: Percent TEI after 17:00 and after 20:00 were associated with TEI (r = 0.13, p = 0.03 for both), and TEI mediated the association between percent TEI after 17:00 and BMI (ß = 0.01 ± 0.01, 95% CI: 0.001, 0.02). Percent TEI after 17:00 was associated with disinhibition (r = 0.13, p = 0.03) and percent TEI after 20:00 was associated with susceptibility to hunger (r = 0.13, p = 0.03), stress (r = 0.24, p = 0.002) and anxiety (r = 0.28, p = 0.0004). In women, disinhibition mediated the association between percent TEI after 17:00 and TEI (ß = 3.41 ± 1.43, 95% CI: 0.92, 6.47). Susceptibility to hunger mediated the association between percent TEI after 20:00 and TEI (ß = 0.96 ± 0.59, 95% CI: 0.02, 2.34) in men and women. Conclusion: Late eating is associated with TEI and suboptimal eating behaviours which could contribute to explaining the association between timing of food intake and obesity.

Interventions to promote healthy lifestyle behaviors in children and adolescents in summer day camps: a scoping review.

BACKGROUND: Children and adolescents have suboptimal physical activity and eating habits during summer breaks. Unlike the school setting, there is little evidence on interventions to promote healthy lifestyle behaviors in Summer Day Camps (SDCs). METHODS: The aim of this scoping review was to examine physical activity, healthy eating, and sedentary behavior interventions in the SDCs. A systematic search on four platforms (EBSCOhost, MEDLINE, EMBASE, and Web of Science) was performed in May 2021 and was updated in June 2022. Studies related to promoting healthy behaviors, physical activity, sedentary behaviors and/or healthy eating among campers aged 6 to 16 in Summer Day Camps were retained. The protocol and writing of the scoping review were done according to the guidelines of the "Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR)". RESULTS: Most interventions had a positive effect on the behavioral determinants or the behaviors themselves (i.e., physical activity, sedentary behaviors, or healthy eating). Involving counsellors and parents, setting camp goals, gardening, and education are all relevant strategies in promoting healthy lifestyle behaviors in SDCs. CONCLUSIONS: Since only one intervention directly targeted sedentary behaviors, it should strongly be considered for inclusion in future studies. In addition, more long-term and experimental studies are needed to establish cause-and-effect relationships between healthy behavior interventions in SDCs and behaviors of children and young adolescents.

Nutrition and immunity: perspectives on key issues and next steps.

In January 2022, a group of experts came together to discuss current perspectives and future directions in nutritional immunology as part of a symposium organized by the Canadian Nutrition Society. Objectives included (1) creating an understanding of the complex interplay between diet and the immune system from infants through to older adults, (2) illustrating the role of micronutrients that are vital to the immune system, (3) learning about current research comparing the impact of various dietary patterns and novel approaches to reduce inflammation, autoimmune conditions, allergies, and infections, and (4) discussing select dietary recommendations aimed at improving disease-specific immune function. The aims of this review are to summarize the symposium and to identify key areas of research that require additional exploration to better understand the dynamic relationship between nutrition and immune function.

Eating behaviour traits mediate the association between satiety responsiveness and energy intake among individuals with overweight and obesity.

Whether eating behaviour traits represent factors that could explain the susceptibility to overeating in individuals with low satiety responsiveness remain to be extensively examined. This study aimed to assess if eating behaviours mediate the association between satiety responsiveness and energy intake. Baseline data from individuals with overweight or obesity (n = 303; age = 38.7 ± 8.4 years; BMI = 33.2 ± 3.4 kg/m2, 56% women) who participated in four weight-loss studies were included in this cross-sectional study. Satiety responsiveness was determined by the satiety quotient (SQ) based on fullness sensations in response to a standardized breakfast. Energy intake was self-reported in a three-day food record and measured by an ad libitum buffet meal. Eating behaviours were assessed with questionnaires. Mediation analyses adjusted for age and sex, and for underreporting for the food record, were performed using a regression-based and bootstrapping approach. The association between SQ and self-reported total energy intake was mediated by susceptibility to hunger (ß = -2.51 ± 1.26, 95% CI, -5.38 to -0.52) and its subscales, internal and external locus of hunger (ß = -2.00 ± 1.10, 95% CI, -4.50 to -0.28 and ß = -2.42 ± 1.29, 95% CI, -5.30 to -0.30, respectively). Susceptibility to hunger (ß = -2.71 ± 1.13, 95% CI, -5.29 to -0.84), internal and external locus of hunger (ß = -1.84 ± 0.95, 95% CI -4.00 to -0.30 and ß = -3.42 ± 1.31, 95% CI, -6.39 to -1.24, respectively), cues that may trigger food cravings (ß = -5.43 ± 2.91, 95% CI, -11.83 to -0.44) and state-craving as a physiological state (ß = -4.31 ± 2.51, 95%CI, -10.14 to -0.44) also mediated the association between SQ and measured energy intake. These results suggest that susceptibility to hunger and food cravings partly explained the susceptibility to overeating among individuals with low satiety responsiveness. Interventions targeting susceptibility to hunger and food cravings may thus be helpful to prevent overeating among these individuals.

Pinning control of networks: Dimensionality reduction through simultaneous block-diagonalization of matrices.

In this paper, we study the network pinning control problem in the presence of two different types of coupling: (i) node-to-node coupling among the network nodes and (ii) input-to-node coupling from the source node to the "pinned nodes." Previous work has mainly focused on the case that (i) and (ii) are of the same type. We decouple the stability analysis of the target synchronous solution into subproblems of the lowest dimension by using the techniques of simultaneous block diagonalization of matrices. Interestingly, we obtain two different types of blocks, driven and undriven. The overall dimension of the driven blocks is equal to the dimension of an appropriately defined controllable subspace, while all the remaining undriven blocks are scalar. Our main result is a decomposition of the stability problem into four independent sets of equations, which we call quotient controllable, quotient uncontrollable, redundant controllable, and redundant uncontrollable. Our analysis shows that the number and location of the pinned nodes affect the number and the dimension of each set of equations. We also observe that in a large variety of complex networks, the stability of the target synchronous solution is de facto only determined by a single quotient controllable block.

The impact of a family web-based nutrition intervention to increase fruit, vegetable, and dairy intakes: a single-blinded randomized family clustered intervention.

BACKGROUND: The importance of adopting healthy eating habits at a young age to prevent obesity and chronic diseases justifies the need for effective interventions. OBJECTIVE: This study evaluated the impact of a family web-based nutrition intervention on vegetable and fruit (V/F) and dairy product (DP) consumption, nutrient intakes, diet quality and BMI or BMI z-scores. METHODS: Forty-three families with children aged 8-16 years were randomized to either the family web-based intervention, or web-based general nutrition guidelines (control) over 8 weeks. Nutritional variables were assessed with three-day dietary records while anthropometry (body weight and height) was assessed with standardized measures at baseline (PRE), immediately after the intervention (POST 1) and 3-6 months after the intervention (POST 2). Linear mixed models for repeated measures were used to assess the main effects and their interactions followed by post hoc tests. RESULTS: The intervention had an effect on DP, total sugar, potassium, magnesium, and calcium in children (Group x Time, P = 0.02 to 0.03) and on DP, V/F juice, carbohydrates, total sugar, saturated fat, protein and calcium in parents (Group x Time, P = 0.01 to 0.03). Post hoc tests revealed children in the intervention group increased their DP intakes immediately after the intervention (POST1) but decreased at follow-up (POST2). No effect of the intervention on V/F, diet quality or BMI was observed. CONCLUSION: Compared to general nutrition guidelines, this family web-based nutrition intervention had a modest effect on nutrient intakes, but beneficial effect on DP intakes in the short term. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03798808 , Registered 10 january 2019 - Retrospectively registered.

Guidance and perspectives on highly processed foods.

Guidance from Health Canada to limit highly processed foods (HPF) seeks to ensure that Canadians remain within intake recommendations for nutrients of concern. However, HPF can contribute to dietary requirements of specific populations. The Canadian Nutrition Society and Institute for the Advancement of Food and Nutritional Sciences convened speakers for a Food for Health workshop in 2021 to provide evidence and perspectives from government, industry, and healthcare on reasons for advocating limits and potential unintended consequences of limiting HPF, and implications and necessity of HPF in clinical settings. This paper discusses advantages and disadvantages of HPF explored at this workshop.

Matryoshka and disjoint cluster synchronization of networks.

The main motivation for this paper is to characterize network synchronizability for the case of cluster synchronization (CS), in an analogous fashion to Barahona and Pecora [Phys. Rev. Lett. 89, 054101 (2002)] for the case of complete synchronization. We find this problem to be substantially more complex than the original one. We distinguish between the two cases of networks with intertwined clusters and no intertwined clusters and between the two cases that the master stability function is negative either in a bounded range or in an unbounded range of its argument. Our proposed definition of cluster synchronizability is based on the synchronizability of each individual cluster within a network. We then attempt to generalize this definition to the entire network. For CS, the synchronous solution for each cluster may be stable, independent of the stability of the other clusters, which results in possibly different ranges in which each cluster synchronizes (isolated CS). For each pair of clusters, we distinguish between three different cases: Matryoshka cluster synchronization (when the range of the stability of the synchronous solution for one cluster is included in that of the other cluster), partially disjoint cluster synchronization (when the ranges of stability of the synchronous solutions partially overlap), and complete disjoint cluster synchronization (when the ranges of stability of the synchronous solutions do not overlap).

Functional neuronal networks reveal emotional processing differences in children with ADHD.

Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder that, in addition to inattention, excessive activity, or impulsivity, makes it difficult for children to process facial emotions and thus to interact with their peers. Here we analyze neuronal networks of children with this disorder by means of the phase-locking value (PLV) method. In particular, we determine the level of phase synchronization between 62 EEG channels of 22 healthy boys and 22 boys with ADHD, recorder whilst observing facial emotions of anger, happiness, neutrality, and sadness. We construct neuronal networks based on the gamma sub-band, which according to previous studies, shows the highest response to emotional stimuli. We find that the functional connectivity of the frontal and occipital lobes in the ADHD group is significantly (P-value < 0.01) higher than in the healthy group. More functional connectivity in these lobes shows more phase synchronization between the neurons of these brain regions, representing some problems in the brain emotional processing center in the ADHD group. The shortest path lengths in these lobes are also significantly (P-value < 0.01) higher in the ADHD group than in the healthy group. This result indicates less efficiency of information transmission and segregation in occipital and frontal lobes of ADHD neuronal networks, responsible for visual and emotional processing in the brain, respectively. We hope that our approach will help obtain further insights into ADHD with methods of network science.

Failure of the simultaneous block diagonalization technique applied to complete and cluster synchronization of random networks.

We discuss here the application of the simultaneous block diagonalization (SBD) of matrices to the study of the stability of both complete and cluster synchronization in random (generic) networks. For both problems, we define indices that measure success (or failure) of application of the SBD technique in decoupling the stability problem into problems of lower dimensionality. We then see that in the case of random networks the extent of the dimensionality reduction achievable is the same as that produced by application of a trivial transformation.

Translation and validation of the Child Three-Factor Eating Questionnaire (CTFEQr17) in French-speaking Canadian children and adolescents.

OBJECTIVE: To translate and validate the Child Three-Factor Eating Questionnaire (CTFEQr17), assessing cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE), among French-speaking Canadian young individuals. DESIGN: Phase 1 comprised a translation and the evaluation of the comprehension of the questionnaire. Phase 2 comprised a confirmatory factor analysis (CFA), the evaluation of internal consistency (Cronbach's α), test-retest reliability (intra-class correlation coefficients (ICC)) and construct validity, including correlations among the CTFEQr17 and Eating Attitudes Test (EAT-26), anthropometrics, dietary intake and diet quality. SETTING: Primary and secondary schools, Québec City, Canada. PARTICIPANTS: Phases 1 and 2 included 20 (40 % boys, mean age 11·5 (sd 2·4) years) and 145 (48 % boys, mean age 11·0 (sd 1·9) years) participants, respectively. RESULTS: Phase 1 resulted in the questionnaire to be used in Phase 2. In Phase 2, the CFA revealed that the seventeen item, three-factor model (CTFEQr17) provided an excellent fit. Internal consistency was good (Cronbach's α: 0·81-0·90). Test-retest reliability was moderate to good (ICC = 0·59, (95 % CI 0·48, 0·70), ICC = 0·78, (95 % CI 0·70, 0·84), ICC = 0·50, (95 % CI 0·38, 0·62) for CR, UE and EE, respectively). CR correlated with EAT-26 score (r = 0·43, P < 0·0001). UE and EE correlated negatively with BMI Z-scores (r = -0;·26, P = 0·003; r = -0;·19, P = 0·03, respectively). CR correlated with the proportion of energy intake from protein and diet quality (r = 0·18, P = 0·04; r = 0·20, P = 0·02, respectively). CONCLUSION: The CTFEQr17 is suitable to use among French-speaking Canadian young individuals.

Validation of the Adult Eating Behaviour Questionnaire adapted for the French-speaking Canadian population.

PURPOSE: The Adult Eating Behaviour Questionnaire (AEBQ) is a newly developed questionnaire adapted from the widely used Child Eating Behaviour Questionnaire. This questionnaire assesses four food approach scales, namely hunger, food responsiveness, emotional overeating (EOE) and enjoyment of food, and four food avoidance scales, namely satiety responsiveness (SR), emotional undereating (EUE), food fussiness and slowness in eating (SE). This study aimed to validate a French version of the AEBQ in controlled conditions among French-speaking adults from Quebec, Canada. METHODS: The AEBQ was pre-tested through structured interviews with 30 individuals. Participants of the validation study (n = 197, aged 19-65 years) had their height and weight measured and completed the AEBQ, Three-Factor Eating Questionnaire (TFEQ) and Intuitive Eating Scale-2 to assess factorial structure, internal consistency and construct validity. Test-retest reliability over 2 weeks was assessed among 144 participants. RESULTS: Confirmatory factor analysis indicated an excellent model fit (NNFI = 0.98, CFI = 0.98, RMSEA = 0.03, χ2/df = 1.17) and provided support for the use of the original 8-factor questionnaire. Internal consistency was adequate for most scales (Cronbach's alpha = 0.66-0.94) and moderate to excellent test-retest reliability was observed for all scales (ICC = 0.70-90). Women showed higher levels of EOE and SR, and individuals with overweight and obesity showed higher levels of EOE and lower levels of EUE and SE. Construct validity was also supported by expected correlations with disinhibition and susceptibility to hunger from the TFEQ and intuitive eating. CONCLUSION: This study indicates that the French AEBQ is a valid and reliable tool to measure eating behaviours in the adult population of Quebec. LEVEL OF EVIDENCE: Level III: Evidence obtained from well-designed cohort or case-control analytic studies. The data are cross-sectional, but all measurement were undertaken in controlled laboratory conditions and the study provided new information.

Cluster synchronization of networks via a canonical transformation for simultaneous block diagonalization of matrices.

We study cluster synchronization of networks and propose a canonical transformation for simultaneous block diagonalization of matrices that we use to analyze the stability of the cluster synchronous solution. Our approach has several advantages as it allows us to: (1) decouple the stability problem into subproblems of minimal dimensionality while preserving physically meaningful information, (2) study stability of both orbital and equitable partitions of the network nodes, and (3) obtain a parameterization of the problem in a small number of parameters. For the last point, we show how the canonical transformation decouples the problem into blocks that preserve key physical properties of the original system. We also apply our proposed algorithm to analyze several real networks of interest, and we find that it runs faster than alternative algorithms from the literature.

Group synchrony, parameter mismatches, and intragroup connections.

Group synchronization arises when two or more synchronization patterns coexist in a network formed of oscillators of different types, with the systems in each group synchronizing on the same time evolution, but systems in different groups synchronizing on distinct time evolutions. Group synchronization has been observed and characterized when the systems in each group are identical and the couplings between the systems satisfy specific conditions. By relaxing these constraints and allowing them to be satisfied in an approximate rather than exact way, we observe that stable group synchronization may still occur in the presence of small deviations of the parameters of the individual systems and of the couplings from their nominal values. We analyze this case and provide necessary and sufficient conditions for stability through a master stability function approach, which also allows us to quantify the synchronization error. We also investigate the stability of group synchronization in the presence of intragroup connections and for this case extend some of the existing results in the literature. Our analysis points out a broader class of matrices describing intragroup connections for which the stability problem can be reduced in a low-dimensional form.

The Impact of Restrictive and Non-restrictive Dietary Weight Loss Interventions on Neurobehavioral Factors Related to Body Weight Control: the Gaps and Challenges.

PURPOSE OF REVIEW: Restrictive diets, such as low-calorie diets, are difficult to maintain in the long term. For this reason, their popularity has decreased compared to non-restrictive approaches, which instead promote healthy eating strategies. Since both strategies may entail different neurobiological mechanisms, this review will examine the current evidence on the effects of restrictive and non-restrictive interventions on neurobehavioral factors. RECENT FINDINGS: Restrictive diets appear to improve eating behaviors, and the evidence reviewed argues against the notion that they may worsen the severity of binge eating. Moreover, they may lead to short-term changes in brain structure and improvements in cerebrovascular markers which, in turn, could impact eating behaviors. Non-restrictive interventions may have a positive effect on weight management and eating behaviors. However, evidence of their neural effects is scarce. Small sample sizes, short follow-ups, and the absence of control groups are limitations of the studies targeting both interventions. Rigorous long-term randomized studies are needed to examine the neurobehavioral effects of restrictive and non-restrictive approaches.