Search

BackgroundOnline interventions can be a cost-effective and efficient way to deliver programs to large numbers of people regardless of geographic location. However, attrition in web-based interventions is often an issue. Developing ways to keep participants engaged is important for ensuring validity and limiting potential biases. We developed a web-based dietary intervention as part of The My Food & Mood study which aimed to optimize ways to engage participants with low mood or depressive symptoms to promote dietary behavior change. Different versions of the My Food & Mood program were tested during optimization. Iterations were developed based on user feedback and usage analysis. ObjectiveThe purpose of this study was to compare engagement and nonusage attrition across 4 program iterations—which differed by platform format, delivery mode, and activity type—to create an optimized version. MethodsEach program version contained modular videos with key activities with respect to implementing behavior change techniques of equivalent levels of required participation and length: version 1.0, desktop program and smartphone app; version 2.1, desktop or smartphone program; version 2.2, desktop program; and version 3.0, smartphone app. Adults with PHQ-8 scores of 5 or greater were recruited online and assigned to 1 of the 4 versions. Participants were asked to use the program for 8 weeks and complete measures at weeks 4 and 8. Engagement data were collected from the web-based platform system logs and customized reports. Cox regression survival analysis examined nonusage attrition and Kruskal-Wallis tests compared engagement across each cohort. ResultsA total of 614 adults participated. Kruskal-Wallis tests showed significant differences across the 4 cohorts in all engagement measures. The smartphone app (version 3.0) had the greatest engagement as measured by weeks engaged, total usage time, total time key activities, number of active sessions, percentage of activities completed against protocol, goals completed, and percentage of videos watched. Cox regression multivariate survival analysis showed referral from a health practitioner (hazard ratio [HR] 0.344, P=.001) and greater proficiency with computers (HR 0.796, P=.049) reduced the risk of nonusage attrition. Computer confidence was associated with an increased risk of nonusage attrition. ConclusionsMy Food & Mood version 3.0, a dietary intervention delivered via smartphone app with self-monitoring tools for diet quality and mood monitoring, was the version with greatest engagement in a population with low mood or depression. The iterative design techniques employed and analysis of feedback from participants resulted in a program that achieved lower rates of nonusage attrition and higher rates of intensity of use.

The field of nutritional psychiatry has generated observational and efficacy data supporting a role for healthy dietary patterns in depression onset and symptom management. To guide future clinical trials and targeted dietary therapies, this review provides an overview of what is currently known regarding underlying mechanisms of action by which diet may influence mental and brain health. The mechanisms of action associating diet with health outcomes are complex, multifaceted, interacting, and not restricted to any one biological pathway. Numerous pathways were identified through which diet could plausibly affect mental health. These include modulation of pathways involved in inflammation, oxidative stress, epigenetics, mitochondrial dysfunction, the gut microbiota, tryptophan-kynurenine metabolism, the HPA axis, neurogenesis and BDNF, epigenetics, and obesity. However, the nascent nature of the nutritional psychiatry field to date means that the existing literature identified in this review is largely comprised of preclinical animal studies. To fully identify and elucidate complex mechanisms of action, intervention studies that assess markers related to these pathways within clinically diagnosed human populations are needed.

Objective: this paper aims to present the evidence for the role of diet in the prevention and treatment of depression, review the potential underlying mechanisms and provide practice recommendations for mental health clinicians. Methods: A literature review was conducted through searches of PubMed with the search terms 'depression', 'diet', 'prevention', 'treatment' and 'mechanisms' and combinations thereof. Additional articles were identified through hand searching. Results: Greater adherence to several healthy dietary patterns, traditional diets such as the Mediterranean diet and other diets such as the DASH diet are associated with or can treat symptoms of depression. Several limitations of the research were noted, many of which relate to inherent challenges of studying diet. Mechanisms by which dietary intervention can influence mood include the gut microbiome, modulation of inflammatory processes, reduction in oxidative stress and modulation of hypothalamic-pituitary-adrenal axis function. Recommendations for mental health clinicians to enable translation of the evidence into practice are provided. Conclusion: Diet can play an important role in preventing and treating depression. Mental health clinicians are well placed to provide dietary counselling and to use clinical judgement in choosing the specific approach that reflects the needs of the patient but are encouraged to refer to a specialist dietitian where necessary. [ABSTRACT FROM AUTHOR]

Context Dietary fibers hold potential to influence depressive and anxiety outcomes by modulating the microbiota–gut–brain axis, which is increasingly recognized as an underlying factor in mental health maintenance. Objective Evidence for the effects of fibers on depressive and anxiety outcomes remains unclear. To this end, a systematic literature review and a meta-analysis were conducted that included observational studies and randomized controlled trials (RCTs). Data sources The PubMed, Embase, CENTRAL, CINAHL, and PsychINFO databases were searched for eligible studies. Data extraction Study screening and risk-of-bias assessment were conducted by 2 independent reviewers. Data analysis Meta-analyses via random effects models were performed to examine the (1) association between fiber intake and depressive and anxiety outcomes in observational studies, and (2) effect of fiber intervention on depressive and anxiety outcomes compared with placebo in RCTs. A total of 181 405 participants were included in 23 observational studies. In cross-sectional studies, an inverse association was observed between fiber intake and depressive (Cohen's d effect size [d]: −0.11; 95% confidence interval [CI]: −0.16, −0.05) and anxiety (d = −0.25; 95%CI, −0.38, −0.12) outcomes. In longitudinal studies, there was an inverse association between fiber intake and depressive outcomes (d = −0.07; 95%CI, −0.11, −0.04). In total, 740 participants were included in 10 RCTs, all of whom used fiber supplements. Of note, only 1 RCT included individuals with a clinical diagnosis of depression. No difference was found between fiber supplementation and placebo for depressive (d = −0.47; 95%CI, −1.26, 0.31) or anxiety (d = −0.30; 95%CI, −0.67, 0.07) outcomes. Conclusion Although observational data suggest a potential benefit for higher fiber intake for depressive and anxiety outcomes, evidence from current RCTs does not support fiber supplementation for improving depressive or anxiety outcomes. More research, including RCTs in clinical populations and using a broad range of fibers, is needed. Systematic Review Registration PROSPERO registration no. CRD42021274898. [ABSTRACT FROM AUTHOR]

Nutritional epidemiological studies have evolved from a focus of single nutrients to diet patterns to capture the protective role of healthy diets on chronic disease development. Similarly, in inflammatory bowel disease (IBD), a healthy diet may be protective against its development in individuals with genetic susceptibility, but the definitions of the optimal diet pattern deserve further exploration. Hence, this review article presents evidence, mainly from prospective cohort studies, for the role of diet quality based on adherence to dietary guidelines, traditional and modern diet patterns in the prevention of IBD. Findings from a limited number of studies on diet quality suggest that high diet quality scores are associated with lower risk of developing Crohn's disease, but the data are inconsistent for ulcerative colitis (UC). There are signals that a Mediterranean diet pattern reduces the risk of Crohn's disease but, again, the data are inconsistent and further studies are much needed. Finally, the evidence is conflicting regarding the role of food additives, with difficulties in the assessment of their intake, namely non‐nutritive sweeteners and emulsifiers, precluding accurate assessment of a relationship with IBD risk. In contrast, emerging evidence for a role of ultra‐processed food in the development of Crohn's disease but not UC is identified. Given the potential influence of diet quality, a Mediterranean diet and ultra‐processed food intake on the risk of Crohn's disease, assessment and implementation of dietary advice for these patients need to be tailored. The search for an optimal diet for UC remains elusive and further research for increasing the evidence in the area is greatly needed. [ABSTRACT FROM AUTHOR]

Summary: Background: Diet is fundamental to the care of irritable bowel syndrome (IBS). However, some approaches are not appropriate for individuals experiencing psychological symptoms. Aims: To assess feasibility of a Mediterranean diet in IBS and its impact on gastrointestinal and psychological symptoms. Methods: We recruited adults with Rome IV IBS and mild or moderate anxiety and/or depressive symptoms to an unblinded 6‐week randomised controlled trial. Patients were randomised to Mediterranean diet counselling or habitual diet. We collected gastrointestinal and psychological symptom data, dietary data and stool samples for metagenomic sequencing. Results: We randomised 59 individuals (29 Mediterranean diet, 30 control); 48 completed the study. The Mediterranean Diet Adherence Screener score was higher in the Mediterranean diet group than controls at week 6 (7.5 [95% CI: 6.9–8.0] vs. 5.7 [5.2–6.3], p < 0.001), and there was a greater score increase than controls (2.1 [95% CI: 1.3–2.9] vs. 0.5 [95% CI: 0.1–1.0], p = 0.004), demonstrating Mediterranean diet feasibility. There was a greater proportion of gastrointestinal symptom responders in the Mediterranean diet group than controls (24/29, 83% vs. 11/30, 37%, p < 0.001) and depression responders (15/29, 52% vs. 6/30 20%, p = 0.015). There was no difference in FODMAP intake at week 6 (p = 0.51). Gastrointestinal adverse events were similar (p = 0.588). There were no differences in change in microbiome parameters between groups. Conclusions: A Mediterranean diet is feasible in IBS and leads to improvement in gastrointestinal and psychological symptoms. Although this study was unblinded, these findings together with the broader benefits of the Mediterranean diet, provide strong impetus for future research in IBS. Australia New Zealand Clinical Trials Registry: ACTRN12620001362987. [ABSTRACT FROM AUTHOR]