How are overweight and obesity associated with reinforcement learning deficits? A systematic review.

Reinforcement learning (RL) refers to the ability to learn stimulus-response or response-outcome associations relevant to the acquisition of behavioral repertoire and adaptation to the environment. Research data from correlational and case-control studies have shown that obesity is associated with impairments in RL. The aim of the present study was to systematically review how obesity and overweight are associated with RL performance. More specifically, the relationship between high body mass index (BMI) and task performance was explored through the analysis of specific RL processes associated with different physiological, computational, and behavioral manifestations. Our systematic analyses indicate that obesity might be associated with impairments in the use of aversive outcomes to change ongoing behavior, as revealed by results involving instrumental negative reinforcement and extinction/reversal learning, but further research needs to be conducted to confirm this association. Hypotheses regarding how obesity might be associated with altered RL were discussed.

A More Supportive Social Environment May Protect Against Nutritional Risk: A Cross-Sectional Analysis Using Data From the Canadian Longitudinal Study on Aging.

BACKGROUND: Nutritional risk has been linked to individual social factors, but the relationship with the overall social environment has not been assessed. OBJECTIVES: To evaluate associations between different support profiles of the social environment and nutritional risk using cross-sectional data from the Canadian Longitudinal Study on Aging (n = 20,206). Subgroup analyses were performed among middle-aged (range, 45-64 y; n = 12,726) and older-aged (≥65 y, n = 7480) adults. Consumption of major food groups [whole grains, proteins, dairy products, and fruits and vegetables (FV)] by social environment profile was a secondary outcome. METHODS: Latent structure analysis (LSA) classified participants into social environment profiles according to data on network size, social participation, social support, social cohesion, and social isolation. Nutritional risk and food group consumption were assessed with the SCREEN-II-AB and Short Dietary questionnaires, respectively. ANCOVA was conducted to compare SCREEN-II-AB mean scores by social environment profile, adjusted for sociodemographic and lifestyle factors. Models were repeated to compare mean food group consumption (times/day) by social environment profile. RESULTS: LSA identified 3 social environment profiles classified as low, medium, and high support (17%, 40%, and 42% of the sample, respectively). Adjusted mean SCREEN-II-AB scores significantly increased with increasing social environment support, with the low support score indicating high nutritional risk status [low, medium, high support, respectively: 37.1 (99% CI: 36.9, 37.4), 39.3 (39.2, 39.5), 40.3 (40.2, 40.5), all comparisons P < 0.0001]. Results were consistent among age subgroups. The low support social environment profile had lower consumption of protein [low, medium, high support, respectively (mean ± SD): 2.17 ± 0.09, 2.21 ± 0.07, 2.23 ± 0.08, P = 0.004], dairy (2.32 ± 0.23, 2.40 ± 0.20, 2.38 ± 0.21, P = 0.009), and FV (3.65 ± 0.23, 3.94 ± 0.20, 4.08 ± 0.21, P < 0.0001), with some variation among age subgroups. CONCLUSIONS: The low support social environment profile had the poorest nutritional outcomes. Therefore, a more supportive social environment may protect against nutritional risk among middle- and older-aged adults.

Social Prescription Interventions Addressing Social Isolation and Loneliness in Older Adults: Meta-Review Integrating On-the-Ground Resources.

BACKGROUND: Social prescription programs represent a viable solution to linking primary care patients to nonmedical community resources for improving patient well-being. However, their success depends on the integration of patient needs with local resources. This integration could be accelerated by digital tools that use expressive ontology to organize knowledge resources, thus enabling the seamless navigation of diverse community interventions and services tailored to the needs of individual users. This infrastructure bears particular relevance for older adults, who experience a range of social needs that impact their health, including social isolation and loneliness. An essential first step in enabling knowledge mobilization and the successful implementation of social prescription initiatives to meet the social needs of older adults is to incorporate the evidence-based academic literature on what works, with on-the-ground solutions in the community. OBJECTIVE: This study aims to integrate scientific evidence with on-the-ground knowledge to build a comprehensive list of intervention terms and keywords related to reducing social isolation and loneliness in older adults. METHODS: A meta-review was conducted using a search strategy combining terms related to older adult population, social isolation and loneliness, and study types relevant to reviews using 5 databases. Review extraction included intervention characteristics, outcomes (social [eg, loneliness, social isolation, and social support] or mental health [eg, psychological well-being, depression, and anxiety]), and effectiveness (reported as consistent, mixed, or not supported). Terms related to identified intervention types were extracted from the reviewed literature as well as descriptions of corresponding community services in Montréal, Canada, available from web-based regional, municipal, and community data sources. RESULTS: The meta-review identified 11 intervention types addressing social isolation and loneliness in older adults by either increasing social interactions, providing instrumental support, promoting mental and physical well-being, or providing home and community care. Group-based social activities, support groups with educational elements, recreational activities, and training or use of information and communication technologies were the most effective in improving outcomes. Examples of most intervention types were found in community data sources. Terms derived from the literature that were the most commonly congruent with those describing existing community services were related to telehealth, recreational activities, and psychological therapy. However, several discrepancies were observed between review-based terms and those addressing the available services. CONCLUSIONS: A range of interventions found to be effective at addressing social isolation and loneliness or their impact on mental health were identified from the literature, and many of these interventions were represented in services available to older residents in Montréal, Canada. However, different terms were occasionally used to describe or categorize similar services across data sources. Establishing an efficient means of identifying and structuring such sources is important to facilitate referrals and help-seeking behaviors of older adults and for strategic planning of resources.

Low socioeconomic status, parental stress, depression, and the buffering role of network social capital in mothers.

BACKGROUND: Pathways underlying the stress-depression relationship in mothers, and the factors that buffer this relationship are not well understood. AIMS: Drawing from the Stress Process model, this study examines (1) if parental stress mediates the association between socioeconomic characteristics and depressive symptoms, and (2) if social support and network capital moderate these pathways. METHOD: Data came from 101 mothers from Montreal. Generalized structural equation models were conducted, with depressive symptoms (CES-D scores) as the outcome, socioeconomic stressors as independent variables, parental stress as the mediator, and social support and network social capital as moderators. RESULTS: Parental stress partially mediated the association between household income and depressive symptoms (indirect effect: ß = -0.09, Bootstrap SE = 0.03, 95% CI = -0.15 to -0.03 p = 0.00). Network diversity moderated the relationship between parental stress and depressive symptoms (ß = -0.25, 95% CI = -0.42 to -0.09, p = 0.00); at high levels of stress, mothers with high compared to low network diversity reported fewer symptoms. CONCLUSION: Findings highlight the role that socioeconomic factors play in influencing women's risk of depression and shaping the benefits that ensue from social resources. Addressing these factors requires interventions that target the social determinants of depression.

Dopamine D4 receptor gene polymorphism (DRD4 VNTR) moderates real-world behavioural response to the food retail environment in children.

BACKGROUND: Evidence for the impact of the food retailing environment on food-related and obesity outcomes remains equivocal, but only a few studies have attempted to identify sub-populations for whom this relationship might be stronger than others. Genetic polymorphisms related to dopamine signalling have been associated with differences in responses to rewards such as food and may be candidate markers to identify such sub-populations. This study sought to investigate whether genetic variation of the dopamine D4 receptor gene (DRD4 exon III 48 bp VNTR polymorphism) moderated the association between local exposure to food retailers on BMI and diet in a sample of 4 to12-year-old children. METHODS: Data collected from a birth cohort and a community cross-sectional study conducted in Montreal, Canada, were combined to provide DRD4 VNTR polymorphism data in terms of presence of the 7-repeat allele (DRD4-7R) for 322 children aged between 4 and 12 (M (SD): 6.8(2.8) y). Outcomes were Body Mass Index (BMI) for age and energy density derived from a Food Frequency Questionnaire. Food environment was expressed as the proportion of local food retailers classified as healthful within 3 km of participants' residence. Linear regression models adjusted for age, sex, income, cohort, and geographic clustering were used to test gene*environment interactions. RESULTS: A significant gene*food environment interaction was found for energy density with results indicating that DRD4-7R carriers had more energy dense diets than non-carriers, with this effect being more pronounced in children living in areas with proportionally more unhealthy food retailers. No evidence of main or interactive effects of DRD4 VNTR and food environment was found for BMI. CONCLUSIONS: Results of the present study suggest that a genetic marker related to dopamine pathways can identify children with potentially greater responsiveness to unhealthy local food environment. Future studies should investigate additional elements of the food environment and test whether results hold across different populations.

Genetically predicted gene expression of prefrontal DRD4 gene and the differential susceptibility to childhood emotional eating in response to positive environment.

Genetic differential susceptibility states that individuals may vary both by exhibiting poor responses when exposed to adverse environments, and disproportionally benefiting from positive settings. The dopamine D4 receptor gene (DRD4) may be particularly implicated in these effects, including disturbed eating behaviors that might lead to obesity. Here, we explore differential susceptibility to positive environments according to the predicted genetically regulated gene expression of prefrontal cortex DRD4 gene. Using MAVAN as the discovery cohort (Maternal Adversity, Vulnerability and Neurodevelopment) and GUSTO as the replication cohort (Growing Up in Singapore Towards Healthy Outcomes), we analyzed the interaction between a) a Positive postnatal environmental score, that accounts for positive outcomes in the postnatal period and b) the genetically regulated gene expression of prefrontal DRD4, computed using a machine learning prediction method (PrediXcan). The outcome measures were the pro-intake domains (Emotional over-eating, Food Responsiveness, Food Enjoyment and Desire to Drink) from the Child Eating Behavior Questionnaire at 48 months of age (MAVAN) and 60 months of age (GUSTO). The interaction between the positive environment and the predicted prefrontal DRD4 gene expression was significant for emotional over-eating in MAVAN (ß = -0.403, p < 0.02), in which the high gene expression group had more or less emotional eating according to the exposure to lower or higher positive environment respectively, showing evidence of differential susceptibility criteria. In the replication cohort, a similar result was found with the pro-intake domain Desire to drink (ß = -0.583, p < 0.05). These results provide further evidence for the genetic differential susceptibility, accounting for the benefit of positive environments.

Social capital and obesity among adults: Longitudinal findings from the Montreal neighborhood networks and healthy aging panel.

Curbing the worldwide increase in obesity requires upstream social interventions that modify the environment in which obesity emerges. Recent studies have suggested that social capital and networks may influence a person's risk of obesity. Yet, few longitudinal studies have assessed whether social capital and networks reduce obesity risk in adult populations. In this study, the data come from three waves (2008, 2010, and 2013) of the Montreal Neighborhood Networks and Health Aging Panel (N=2606). Self-reported height and weight were used to calculate body mass index (BMI) with obesity defined as a BMI>30. Name and position generator instruments captured network measures of social capital, including: (1) upper reachability, (2) range, (3) diversity and (4) the number of kin ties. Questions on generalized trust and participation were used to assess cognitive and structural dimensions of social capital. Separate random effects logistic regression was used to examine the association among social network characteristics, social capital, and obesity. We found the greater the number of kin ties in a person's network, the greater the risk of obesity (OR: 1.33, 95% CI: 1.08-1.62). Adults with higher network diversity (OR: 0.83, 95% CI: 0.72-0.96) and high generalized trust (OR: 0.52, 95% CI: 0.35-0.77) were at a lower the risk of obesity. The current study confirmed that higher network capital and trust were protective against obesity, while having kin ties was not. Disentangling the multidimensional role that social capital plays can lead to more effective interventions to reduce obesity.

Low birth weight is associated with increased fat intake in school-aged boys.

Evidence suggests that both high and low birth weight children have increased the risk for obesity and the metabolic syndrome in adulthood. Previously we have found altered feeding behaviour and food preferences in pre-school children and adults born with low birth weight. In this study, we investigated if birth weight was associated with different intake of fat, carbohydrate and/or protein at 6-12 years of age. This is a cross-sectional study where 255 guardians answered online and telephone questions including anthropometrics and demographic data, parental family food rules (food control, encouragement and restriction) and a complete web-based FFQ for their children (130 boys and 125 girls). Baseline demographic and parental food rules characteristics did not differ accordingly to sex. Linear regression models were conducted separately for each sex, adjusted for income, age and maternal age. There were no differences in total energy intake, but energy density (ED, energy content/g) was negatively associated with birth weight in boys. Macronutrient analysis showed that ED intake was from a greater intake of fat. Birth weight was not a significant predictor of protein and carbohydrate intake in boys. In girls, we saw a positive correlation between fat intake and cholesterol intake v. birth weight, but no association with ED intake (results did not remain after adjustment). The study shows that low birth weight is associated with altered fat intake in childhood in a sex-specific manner. It is likely that biological factors such as fetal programming of homoeostatic and/or hedonic pathways influencing food preferences are involved in this process.

Attachment and eating: A meta-analytic review of the relevance of attachment for unhealthy and healthy eating behaviors in the general population.

Attachment relationships play an important role in people's wellbeing and affliction with physical and mental illnesses, including eating disorders. Seven reviews from the clinical field have consistently shown that higher attachment insecurity-failure to form trusting and reliable relationships with others-systematically characterized individuals with eating disorders. Nevertheless, to date, it is unclear whether (and if so how) these findings apply to the population at large. Consequently, the objective of the present meta-analysis is to quantify the relationship between attachment and unhealthy and healthy eating in the general population. Data from 70 studies and 19,470 participants were converted into r effect sizes and analysed. Results showed that higher attachment insecurity (r = 0.266), anxiety (r = 0.271), avoidance (r = 0.119), and fearfulness (r = 0.184) was significantly associated with more unhealthy eating behaviors, ps = 0.000; conversely, higher attachment security correlated with lower unhealthy eating behaviors (r = -0.184, p = 0.000). This relationship did not vary across type of unhealthy eating behavior (i.e., binge eating, bulimic symptoms, dieting, emotional eating, and unhealthy food consumption). The little exploratory evidence concerning healthy eating and attachment was inconclusive with one exception-healthy eating was associated with lower attachment avoidance (r = -0.211, p = 0.000). Our results extend previous meta-analytic findings to show that lack of trusting and reliable relationships does not only set apart eating disordered individuals from controls, but also characterizes unhealthy eating behaviors in the general population. More evidence is needed to determine how attachment and healthy eating are linked and assess potential mechanisms influencing the attachment-eating relationship.

Fetal growth interacts with multilocus genetic score reflecting dopamine signaling capacity to predict spontaneous sugar intake in children.

BACKGROUND: We have shown that intrauterine growth restriction (IUGR) leads to increased preference for palatable foods at different ages in both humans and rodents. In IUGR rodents, altered striatal dopamine signaling associates with a preference for palatable foods. OBJECTIVES: Our aim was to investigate if a multilocus genetic score reflecting dopamine-signaling capacity is differently associated with spontaneous palatable food intake in children according to the fetal growth status. METHODS: 192 four-year old children from a community sample from Montreal and Hamilton, Canada, were classified according to birth weight and administered a snack test meal containing regular as well as palatable foods. Intrauterine growth restriction was based on the birth weight ratio below 0.85; children were genotyped for polymorphisms associated with dopamine (DA) signaling, with the hypofunctional variants (TaqIA-A1 allele, DRD2-141C Ins/Ins, DRD4 7-repeat, DAT1-10-repeat, Met/Met-COMT) receiving the lowest scores, and a composite score was calculated reflecting the total number of the five genotypes. Macronutrient intake during the Snack Test was the outcome. RESULTS: Adjusting for z-score BMI at 48 months and sex, there was a significant interaction of the genetic profile and fetal growth on sugar intake [߈ = -4.56, p = 0.04], showing a positive association between the genetic score and sugar intake in IUGR children, and no association in non-IUGR children. No significant interactions were seen in other macronutrients. CONCLUSIONS: Variations in a genetic score reflecting DA signaling are associated with differences in sugar intake only in IUGR children, suggesting that DA function is involved in this behavioral feature in these children. This may have important implications for obesity prevention in this population.

A DRD4 gene by maternal sensitivity interaction predicts risk for overweight or obesity in two independent cohorts of preschool children.

BACKGROUND: Recent evidence suggests that early exposure to low maternal sensitivity is a risk factor for obesity in children and adolescents. A separate line of study shows that the seven-repeat (7R) allele of the dopamine-4 receptor gene (DRD4) increases susceptibility to environmental factors including maternal sensitivity. The current study integrates these lines of work by examining whether preschoolers carrying the 7R allele are more vulnerable to low maternal sensitivity as it relates to overweight/obesity risk. METHOD: The Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) project in Canada was used as the discovery cohort (N = 203), while the Generation R study in the Netherlands was used as a replication sample (N = 270). Regression models to predict both continuous BMI z-scores and membership in any higher BMI category based on established World Health Organization (WHO) cutoffs for 48 months of age were completed. RESULTS: In both cohorts, there was a significant maternal sensitivity by DRD4 by sex interaction predicting higher body mass indices and/or obesity risk. As hypothesized, post hoc testing revealed an inverse relationship between maternal sensitivity and body mass indices in 7R allele carriers relative to noncarriers. This finding was strongest in girls in the Canadian cohort and in boys in the Dutch cohort. CONCLUSIONS: Many children who carry the 7R allele of DRD4 appear to be more influenced by maternal sensitivity as it relates to overweight/obesity risk, consistent with a plasticity effect. Given the relatively small sample sizes available for these analyses, further replications will be needed to confirm and extend these results.

The moderating role of food cue sensitivity in the behavioral response of children to their neighborhood food environment: a cross-sectional study.

BACKGROUND: Neighborhood food cues have been inconsistently related to residents' health, possibly due to variations in residents' sensitivity to such cues. This study sought to investigate the degree to which children's predisposition to eat upon exposure to food environment and food cues (external eating), could explain differences in strength of associations between their food consumption and the type of food outlets and marketing strategies present in their neighborhood. METHODS: Data were obtained from 616 6-12 y.o. children recruited into a population-based cross-sectional study in which food consumption was measured through a 24-h food recall and responsiveness to food cues measured using the external eating scale. The proportion of food retailers within 3 km of residence considered as "healthful" was calculated using a Geographical Information System. Neighborhood exposure to food marketing strategies (displays, discount frequency, variety, and price) for vegetables and soft drinks were derived from a geocoded digital marketing database. Adjusted mixed models with spatial covariance tested interaction effects of food environment indicators and external eating on food consumption. RESULTS: In children with higher external eating scores, healthful food consumption was more positively related to vegetable displays, and more negatively to the display and variety of soft drinks. No interactions were observed for unhealthful food consumption and no main effects of food environment indicators were found on food consumption. CONCLUSIONS: Children differ in their responsiveness to marketing-related visual food cues on the basis of their external eating phenotype. Strategies aiming to increase the promotion of healthful relative to unhealthful food products in stores may be particularly beneficial for children identified as being more responsive to food cues.

A systems science perspective and transdisciplinary models for food and nutrition security.

We argue that food and nutrition security is driven by complex underlying systems and that both research and policy in this area would benefit from a systems approach. We present a framework for such an approach, examine key underlying systems, and identify transdisciplinary modeling tools that may prove especially useful.

Paths of convergence for agriculture, health, and wealth.

This special feature calls for forward thinking around paths of convergence for agriculture, health, and wealth. Such convergence aims for a richer integration of smallholder farmers into national and global agricultural and food systems, health systems, value chains, and markets. The articles identify analytical innovation, where disciplines intersect, and cross-sectoral action where single, linear, and siloed approaches have traditionally dominated. The issues addressed are framed by three main themes: (i) lessons related to agricultural and food market growth since the 1960s; (ii) experiences related to the integration of smallholder agriculture into national and global business agendas; and (iii) insights into convergence-building institutional design and policy, including a review of complexity science methods that can inform such processes. In this introductory article, we first discuss the perspectives generated for more impactful policy and action when these three themes converge. We then push thematic boundaries to elaborate a roadmap for a broader, solution-oriented, and transdisciplinary approach to science, policies, and actions. As the global urban population crosses the 50% mark, both smallholder and nonsmallholder agriculture are keys in forging rural-urban links, where both farm and nonfarm activities contribute to sustainable nutrition security. The roadmaps would harness the power of business to reduce hunger and poverty for millions of families, contribute to a better alignment between human biology and modern lifestyles, and stem the spread of noncommunicable chronic diseases.

Reciprocal Markov Modeling of Feedback Mechanisms Between Emotion and Dietary Choice Using Experience-Sampling Data.

With intensively collected longitudinal data, recent advances in the experience-sampling method (ESM) benefit social science empirical research, but also pose important methodological challenges. As traditional statistical models are not generally well equipped to analyze a system of variables that contain feedback loops, this paper proposes the utility of an extended hidden Markov model to model reciprocal the relationship between momentary emotion and eating behavior. This paper revisited an ESM data set (Lu, Huet, & Dube, 2011) that observed 160 participants' food consumption and momentary emotions 6 times per day in 10 days. Focusing on the analyses on feedback loop between mood and meal-healthiness decision, the proposed reciprocal Markov model (RMM) can accommodate both hidden ("general" emotional states: positive vs. negative state) and observed states (meal: healthier, same or less healthy than usual) without presuming independence between observations and smooth trajectories of mood or behavior changes. The results of RMM analyses illustrated the reciprocal chains of meal consumption and mood as well as the effect of contextual factors that moderate the interrelationship between eating and emotion. A simulation experiment that generated data consistent with the empirical study further demonstrated that the procedure is promising in terms of recovering the parameters.

Association between the seven-repeat allele of the dopamine-4 receptor gene (DRD4) and spontaneous food intake in pre-school children.

BACKGROUND: Studies in adults show associations between the hypofunctional seven-repeat allele (7R) of the dopamine-4 receptor gene (DRD4), increased eating behaviour and/or obesity, particularly in females. We examined whether 7R is associated with total caloric intake and/or food choices in pre-schoolers. METHODS: 150 four-year-old children taking part in a birth cohort study in Canada were administered a snack test meal in a laboratory setting. Mothers also filled out a food frequency questionnaire to address childrens' habitual food consumption. Total caloric and individual macronutrient intakes during the snack meal and specific types of foods as reported in the food diaries were compared across 7R allele carriers vs. non-carriers, using current BMI as a co-variate. RESULTS: We found significant sex by genotype interactions for fat and protein intake during the snack test. Post hoc testing revealed that in girls, but not boys, 7R carriers ate more fat and protein than did non-carriers. Based on the food diaries, across both sexes, 7R carriers consumed more portions of ice cream and less vegetables, eggs, nuts and whole bread, suggesting a less healthy pattern of habitual food consumption. CONCLUSION: The 7R allele of DRD4 influences macronutrient intakes and specific food choices as early as four years of age. The specific pattern of results further suggests that prior associations between the 7R allele and adult overeating/obesity may originate in food choices observable in the preschool years. Longitudinal follow-up of these children will help establish the relevance of these findings for obesity risk and prevention.

Accounting for multiscale processing in adaptive real-world decision-making via the hippocampus.

For adaptive real-time behavior in real-world contexts, the brain needs to allow past information over multiple timescales to influence current processing for making choices that create the best outcome as a person goes about making choices in their everyday life. The neuroeconomics literature on value-based decision-making has formalized such choice through reinforcement learning models for two extreme strategies. These strategies are model-free (MF), which is an automatic, stimulus-response type of action, and model-based (MB), which bases choice on cognitive representations of the world and causal inference on environment-behavior structure. The emphasis of examining the neural substrates of value-based decision making has been on the striatum and prefrontal regions, especially with regards to the "here and now" decision-making. Yet, such a dichotomy does not embrace all the dynamic complexity involved. In addition, despite robust research on the role of the hippocampus in memory and spatial learning, its contribution to value-based decision making is just starting to be explored. This paper aims to better appreciate the role of the hippocampus in decision-making and advance the successor representation (SR) as a candidate mechanism for encoding state representations in the hippocampus, separate from reward representations. To this end, we review research that relates hippocampal sequences to SR models showing that the implementation of such sequences in reinforcement learning agents improves their performance. This also enables the agents to perform multiscale temporal processing in a biologically plausible manner. Altogether, we articulate a framework to advance current striatal and prefrontal-focused decision making to better account for multiscale mechanisms underlying various real-world time-related concepts such as the self that cumulates over a person's life course.

Social isolation is linked to classical risk factors of Alzheimer's disease-related dementias.

Alzheimer's disease and related dementias is a major public health burden-compounding over upcoming years due to longevity. Recently, clinical evidence hinted at the experience of social isolation in expediting dementia onset. In 502,506 UK Biobank participants and 30,097 participants from the Canadian Longitudinal Study of Aging, we revisited traditional risk factors for developing dementia in the context of loneliness and lacking social support. Across these measures of subjective and objective social deprivation, we have identified strong links between individuals' social capital and various indicators of Alzheimer's disease and related dementias risk, which replicated across both population cohorts. The quality and quantity of daily social encounters had deep connections with key aetiopathological factors, which represent 1) personal habits and lifestyle factors, 2) physical health, 3) mental health, and 4) societal and external factors. Our population-scale assessment suggest that social lifestyle determinants are linked to most neurodegeneration risk factors, highlighting them as promising targets for preventive clinical action.

Adherence to a caloric budget and body weight change vary by season, gender, and BMI: An observational study of daily users of a mobile health app.

Objective: Self-monitoring, one of the most important behaviors for successful weight loss, can be facilitated through mobile health applications (mHealth apps). Therefore, it is of interest to determine whether consistent users of these apps succeed in achieving their weight goals. This study used data from an mHealth app that enabled tracking of caloric intake, body weight, and physical activity and provided a caloric budget depending on weight goal. The primary objective was to evaluate adherence to caloric budget and body weight change among the most consistent (i.e., daily) trackers of caloric intake over a calendar year (n = 9372, 50% male). Methods: Gender-stratified linear mixed models were conducted to examine the effects of quarter of year (Q1-Q4 as season proxies) and body mass index (BMI) group (normal weight, overweight, obesity) on adherence to a caloric budget (kcal/day). Change in body weight was analyzed using a subset of users (n = 5808) who entered their weight in the app at least once per week, once per month, or once in Q1 and Q4. Physical activity entries were evaluated in exploratory analyses. Results: Only users with obesity met their caloric budget in Q1. Deviation from budget increased for all groups from Q1 to Q2 (mean change[±standard error of the mean]: +23.7[±1.8] and +39.7[±2.2] kcal/day for female and male users, p < 0.001), was stable between Q2 and Q3, and fluctuated thereafter depending on gender and BMI, with greater deviation among males with overweight. Users with obesity with weight entries at least once per month lost the most weight (-6.1[±0.3] and -4.5[±0.3] kg for females and males, p < 0.001). Physical activity was highest in the summer months. Conclusions: Among consistent calorie trackers, adherence to a caloric budget and body weight vary by season, gender, and BMI. Self-monitoring of body weight in addition to calorie tracking may lead to improved weight loss outcomes.

Design for a Virtual Peer-to-Peer Knowledge to Action Platform for Type 2 Diabetes.

Many patients with Type 2 Diabetes (T2D) have difficulty in controlling their disease despite wide-spread availability of high-quality guidelines, T2D education programs and primary care follow-up programs. Current diabetes education and treatment programs translate knowledge from bench to bedside well, but underperform on the 'last-mile' of converting that knowledge into action (KTA). Two innovations to the last-mile problem in management of patients with T2D are introduced. 1) Design of a platform for peer-to-peer groups where patients can solve KTA problems together in a structured and psychologically safe environment using all the elements of the Action Cycle phase of the KTA framework. The platform uses Self-Determination Theory as the behavior change theory. 2) A novel patient segmentation method to enable the formation of groups of patients who have similar behavioral characteristics and therefore who are more likely to find common cause in the fight against diabetes.