How eating-related social media postings influence healthy eating in senders and network members: Two field experiments with intensive longitudinal data.

Young adults are frequently confronted with eating-related social media content. How such exposure influences eating in those who post and their network members is largely unknown. We conducted two intensive longitudinal field experiments combining self-reports with social media data. The posting behavior of young adults was manipulated. We examined how postings about fruit and vegetables affected intake in senders and their network members (Study 1, N = 81) and in senders with a change goal (Study 2, N = 128). Potential mechanisms of action were explored. Descriptively, posting led to a stronger increase of senders' and network members' intake, but this increase was not statistically significant. Posting led to higher perceived social support and injunctive norms of senders (Study 1). Posting supported eating behavior change; the effect size was comparable to picture-based self-monitoring of intake (Study 2). Intraindividual variations in senders' daily eating-related social media activities were associated with daily eating behavior and perceived social support (both studies), daily self-efficacy, experiential and instrumental attitudes, and goal commitment (Study 2). Our studies underline that social media environments should be considered in research and interventions targeting eating behavior of young adults.

Effects of behavioral performance, intrinsic reward value, and context stability on the formation of a higher-order nutrition habit: an intensive longitudinal diary study.

BACKGROUND: Habits drive many of our health behaviors in our daily lives. However, little is known about the relative contribution of different key factors for habit formation in real-world contexts. We examined the effects of behavioral performance, intrinsic reward value (operationalized as tastiness), and context stability on the formation of a higher-order nutrition habit. METHODS: Participants were recruited via mailing lists and posts on social media platforms. N = 199 participants (Mage = 37.10 years, SD = 13.00, 86.93% female) received an online intervention for building the higher-order habit of filling half of their plates with vegetables at dinner and completed one daily online survey for up to 56 days, including the assessment of habit strength, behavioral performance, intrinsic reward value, and context stability, providing a total of N = 6352 daily measurements. N = 189 participants (N = 4175 measurements) could be included in the primary analysis. Utilizing multilevel modeling, we analyzed the impact of behavioral performance, intrinsic reward value, and context stability, as well as their interaction effects, on habit strength on the next day. RESULTS: Habit strength significantly increased over time. This effect was strengthened in persons with high mean levels of behavioral performance. Furthermore, mean levels of behavioral performance, intrinsic reward value, and context stability were all positively related to mean levels of habit strength. There were no positive effects of daily intraindividual variations in the three examined factors on habit strength at the next day. There was an unexpected negative effect of daily behavioral performance on habit strength at the next day. We found little to no evidence for our expected and pre-registered interaction effects. In an additional exploratory analysis, there were positive effects of daily intraindividual variations in the three factors on habit strength at the same day. CONCLUSIONS: We found that behavioral performance, intrinsic reward value, and context stability were all independent predictors of habit strength of a higher-order habit at the between-person level. However, we did not find the expected associations at the within-person level. Habit interventions should promote the consistent performance of the target behaviors in stable contexts. TRIAL REGISTRATION: https://aspredicted.org/blind.php?x=vu2cg4 . Registered 28.04.2020.

A theory-based video intervention to enhance communication and engagement in online health communities: two experiments.

BACKGROUND: Online communities and social networking sites have great potential for supporting health behavior change. However, interventions vary greatly in participants' engagement rates and, consequently, their effectiveness. Theory-based interventions in real-world contexts are needed to further increase engagement and effectiveness. METHODS: We experimentally tested whether a video intervention teaching Self-Determination-Theory-based communication strategies increases need-supportive communication strategy use over one week (Study 1, N = 76) and perceived need support, engagement, and goal attainment in a behavior change intervention supported by a forum-based online community (Study 2, N = 537). In Study 2, participants chose a goal (increasing either fruit or vegetable consumption or increasing moderate or vigorous physical activity) and joined an online community for 2 weeks. Data from both experiments were analyzed with mixed models and follow-up tests. RESULTS: In Study 1, participants in the intervention but not in the control group showed an increase in the number of need-supportive communication strategies used both immediately and one week after the intervention (condition × time interaction, partial η 2 = 0.31). In Study 2, participants who watched the intervention video had a higher number of postings and reported a higher subjective forum use frequency (but not a higher number of logins) compared to participants who watched the control video. However, the effect on the subjective forum visit frequency was not robust. There were no intervention effects on perceived need support, goal attainment, or secondary outcomes. The results might be explained by low application of need-supportive communication strategies. CONCLUSION: A brief video intervention may be a suitable, low-cost intervention to promote need-supportive communication strategy use, benefitting both engagement and behavior change. Future studies should incorporate additional means to further improve communication strategy uptake and engagement in online communities.

Evaluation of a new screening instrument for psychological distress in postacute rehabilitation in older person.

PURPOSE: Although psychological distress has a negative impact on functional recovery, institutionalisation and mortality rates, there is typically no established procedure to screen for psychological distress in geriatric rehabilitation. The aim of the study was to evaluate a brief single-item Verbal Numerical Rating Scale (VNRS-PD) as a screening tool for psychological distress in multimorbid geriatric rehabilitation patients. METHODS: In this cross-sectional study, N = 132 geriatric rehabilitation in-patients (M = 82 years old; 70.5% female) completed a verbal numerical rating scale (VNRS-PD) on satisfaction with their mood as well as the Hospital Anxiety and Depression Scale (HADS) and the short-form of the Geriatric Depression Scale (GDS). Based on the questionnaire data, the rehabilitation patients were classified as high or low in psychopathology. Using receiver-operating characteristic (ROC) curve analysis, optimal cutoff scores of the VNRS-PD were calculated for each questionnaire to detect significant psychological distress. RESULTS: Between 28.8% (HADS ≥ 18) and 43.9% (GDS ≥ 6) of the sample had above-cutoff questionnaire scores. The area under the curve (AUC) of the VNRS-PD varied from 0.785 (95%-CI 0.709-0.861) (GDS ≥ 6) and 0.790 (95%-CI 0.716-0.864) (HADS ≥ 18) to 0.807 (95%-CI 0.734-0.880) (GDS ≥ 7). A score of ≤ 5 in the VNRS-PD proved to be the cutoff with an optimal trade-off between sensitivity (0.776-0.867) and specificity (0.638-0.703). CONCLUSION: The VNRS-PD may be a suitable screening instrument to detect patients with psychological distress in inpatient geriatric rehabilitation for and to initiate further diagnostics within a graduated psychodiagnostic scheme. This first step may help to identify older patients with psychological distress and mental disorders, to initiate targeted interventions. Further research is needed to replicate these findings in a larger sample.

An intramembrane aromatic network determines pentameric assembly of Cys-loop receptors.

Cys-loop receptors are pentameric ligand-gated ion channels (pLGICs) that mediate fast synaptic transmission. Here functional pentameric assembly of truncated fragments comprising the ligand-binding N-terminal ectodomains and the first three transmembrane helices, M1-M3, of both the inhibitory glycine receptor (GlyR) alpha1 and the 5HT(3)A receptor subunits was found to be rescued by coexpressing the complementary fourth transmembrane helix, M4. Alanine scanning identified multiple aromatic residues in M1, M3 and M4 as key determinants of GlyR assembly. Homology modeling and molecular dynamics simulations revealed that these residues define an interhelical aromatic network, which we propose determines the geometry of M1-M4 tetrahelical packing such that nascent pLGIC subunits must adopt a closed fivefold symmetry. Because pLGIC ectodomains form random nonstoichiometric oligomers, proper pentameric assembly apparently depends on intersubunit interactions between extracellular domains and intrasubunit interactions between transmembrane segments.