Assessing the effects of vegetable consumption on the psychological health of healthy adults: a systematic review of prospective research

Baseline higher hair cortisol moderated some effects in a healthy lifestyle intervention

Children and families from socioeconomically marginalized background experience high levels of stress, especially persistent chronic stress, due to unstable housing, employment, and food insecurity. Although consistent evidence supports a stress-obesity connection, little research has examined the potential moderation role of stress in childhood obesity interventions. Therefore, this study aimed to explore how chronic stress (hair cortisol) moderated the effects of a healthy lifestyle intervention on improving behavioral and anthropometric outcomes among 95 socioeconomically marginalized parent-child dyads. Data were collected in a cluster randomized controlled trial with 10 Head Start childcare centers being randomized into intervention and control. The child sample (3-5 years old) included 57.9 % female, 12.6 % Hispanic, and 40.0 % Black. For the parents, 91.6 % were female, 8.4 % were Hispanic, 36.8 % were Black, and 56.8 % were single. Parent baseline hair cortisol significantly moderated the intervention effects on child fruit intake (B = -1.56, p = .030) and parent nutrition self-efficacy (B = 1.49, p = .027). Specifically, higher parent hair cortisol lowered the increases in child fruit intake but improved the increases in parent nutrition self-efficacy in the intervention group compared to control group. Child higher baseline hair cortisol was significantly associated with the decreases in child fruit intake (B = -0.60, p = .025). Child baseline hair cortisol significantly moderated the intervention effects on parent physical activity (PA) self-efficacy (B = -1.04, p = .033) and PA parental support (B = -0.50, p = .016), with higher child hair cortisol decreasing the improvement on these two outcomes in the intervention group compared to control group. Results from this study shed lights on the moderation role of chronic stress on impacting healthy lifestyle intervention effects. Although needing further investigation, the adverse effects of chronic stress on intervention outcomes should be considered when developing healthy lifestyle interventions for preschoolers and their families.

Association between junk food consumption and mental health problems in adults: a systematic review and meta-analysis

BACKGROUND

Anxiety and depression can seriously undermine mental health and quality of life globally. The consumption of junk foods, including ultra-processed foods, fast foods, unhealthy snacks, and sugar-sweetened beverages, has been linked to mental health. The aim of this study is to use the published literature to evaluate how junk food consumption may be associated with mental health disorders in adults.

METHODS

A systematic search was conducted up to July 2023 across international databases including PubMed/Medline, ISI Web of Science, Scopus, Cochrane, Google Scholar, and EMBASE. Data extraction and quality assessment were performed by two independent reviewers. Heterogeneity across studies was assessed using the I2 statistic and chi-square-based Q-test. A random/fixed effect meta-analysis was conducted to pool odds ratios (ORs) and hazard ratios (HRs).

RESULTS

Of the 1745 retrieved articles, 17 studies with 159,885 participants were suitable for inclusion in the systematic review and meta-analysis (seven longitudinal, nine cross-sectional and one case-control studies). Quantitative synthesis based on cross-sectional studies showed that junk food consumption increases the odds of having stress and depression (OR = 1.15, 95% CI: 1.06 to 1.23). Moreover, pooling results of cohort studies showed that junk food consumption is associated with a 16% increment in the odds of developing mental health problems (OR = 1.16, 95% CI: 1.07 to 1.24).

CONCLUSION

Meta-analysis revealed that consumption of junk foods was associated with an increased hazard of developing depression. Increased consumption of junk food has heightened the odds of depression and psychological stress being experienced in adult populations.

Eat healthy, feel better: Are differences in employees' longitudinal healthy-eating trajectories reflected in better psychological well-being?

Eating healthily in terms of fruit and vegetable consumption has beneficial effects for employees and their organisations. Yet, we know little about how employees' eating behaviour develops over longer periods of time (trajectories) as well as about how subgroups of employees in these trajectories differ (trajectory classes). Gaining such insights is critical to understand how employees address healthy eating recommendations over time as well as to develop individualised interventions that also consider the development of healthy eating (i.e. improvement versus impairment beyond mean levels). We analysed panel data (Longitudinal Internet Studies for the Social Sciences) from 1054 employees by means of growth mixture modelling. Our analyses revealed three relevant classes of healthy-eating trajectories: a favourable trajectory class, an unfavourable trajectory class and a strongly improving trajectory class. Furthermore, unfavourable healthy-eating trajectories were especially critical with respect to impaired psychological well-being. Specifically, we found robust results for impaired positive and negative affects, but not for self-esteem, in the unfavourable trajectory class. We discuss limitations and implications of these findings, thereby encouraging research and practice to further consider such fine-grained approaches (i.e. focusing on subgroups within a larger population) when addressing healthy-eating promotion over time.

Does fruit and vegetable consumption impact mental health? Systematic review and meta-analyses of published controlled intervention studies

Associations between fruit and vegetable (FV) consumption and mental health are suggested, largely from observational studies. This systematic review aimed to identify and summarise all published controlled intervention studies investigating the effects of FV consumption on mental health in adults. Four academic databases (Medline, PsycINFO, PubMed, Web of Science) were searched on 16 September 2022, over all years, for studies that used an intervention design; included FV consumption; included an appropriate non-FV-consumption control; used a validated measure of mental health and were conducted in healthy adults or adults with solely a depressive or anxiety-related condition. Study details were tabulated and combined using meta-analyses. Risk of bias was assessed using the domains of the Cochrane Collaboration. Six studies, enrolling 691 healthy adults and reporting on one or more mental health outcomes, were found. Meta-analyses found small and imprecise effects of FV consumption for: psychological well-being (4 studies, 289 participants) standardised mean difference (SMD) = 0·07 (95 % CI -0·17, 0·30), P = 0·58, I2 = 0 %; depressive symptomology (3 studies, 271 participants) SMD = -0·15 (95 % CI -0·40, 0·10), P = 0·23, I2 = 47 % and anxiety-related symptomology (4 studies, 298 participants) SMD = -0·15 (95 % CI -0·39, 0·08), P = 0·20, I2 = 71 %. Some benefit for psychological well-being was found in change-from-baseline data: SMD = 0·28 (95 % CI 0·05, 0·52), P = 0·02, I2 = 0 %. Risk of bias was high in many studies. Limitations include the consideration only of published studies and stem from the studies found. Given the few, limited studies available and the small size of effects, stronger evidence is needed before recommending FV consumption for mental health.

[Dietary patterns and factors and their association with the anxiety in adult population: proposed recommendations based on a scoping review of systematic reviews and meta-analyses]

Introduction

A high percentage of the population suffers from anxiety, a disorder that can be influenced by dietary habits. The aim of this review was to compile the existing evidence on dietary patterns and factors, and their association with anxiety to propose clinically applicable recommendations. A scoping review of systematic reviews and meta-analyses was conducted in the MEDLINE database (PubMed) until January 2021, reporting the main findings based on PRISMA (2020). To construct the search strategy, MeSH language, keywords ("diet", "nutrients", "healthy lifestyle", "anxiety") and filters were used, combined using Boolean operators. Twelve articles, seven systematic reviews with meta-analysis and five systematic reviews were selected. Several results were obtained evaluating the relationship between anxiety and different aspects of diet. The main associations found were between increased consumption of raw vegetables and fruits, substitution of refined cereals by whole grains, intake of omega-3 and omega-6 fats, and increased intake of minerals and vitamins, tryptophan and antioxidants. Based on the systematic reviews and meta-analyses included as findings, ten recommendations on food consumption that should be considered as a priority for these patients were proposed. Based on the literature reviewed, it is concluded that there are dietary patterns and factors that could have a stronger positive influence on anxiety. This proposal of evidence-based dietary recommendations may allow healthcare professionals to have updated recommendations to provide a first orientation.

Increased fruit intake is associated with reduced risk of depression: evidence from cross-sectional and Mendelian randomization analyses

Background

The association between dietary patterns and depression has gained significant attention, but the relationship between fruit intake and depression remains unclear. This study aimed to investigate the role of fruit intake in the risk of depression using data from the National Health and Nutrition Examination Survey (NHANES) and Mendelian randomization (MR) analysis, and further explore the causal relationship between them.

Materials and methods

Cross-sectional analysis was conducted using the 2005-2018 NHANES data. Specialized weighted complex survey design analysis software was used for multivariate logistic analysis. Additionally, genetic variants for fruit intake and depression, as well as its related neuroticism traits, from the GWAS were used as instrumental variables in MR analysis. The inverse variance weighted (IVW) method was employed as the primary analysis method to evaluate the causal relationship between them. MR-Egger regression, MR-PRESSO test, and leave-one-out analysis were conducted to assess heterogeneity and pleiotropy.

Results

In NHANES, compared to the lowest quartile (Q1, <0.12 cup], the highest quartile (Q4, >1.49 cups) of fruit intake showed a significant reduction in the risk of depression after adjusting for relevant covariates. Model 3, after rigorous adjustment for multiple covariates, demonstrated improved predictive performance in both Receiver operating characteristic (ROC) curve and Decision curve analysis (DCA). In Model 3, the proportion of reduced depression risk associated with fruit intake reached 31% (OR = 0.69, 95% CI: 0.50-0.95). This association remained significant in the MR analysis (OR = 0.92, 95% CI = 0.87-0.96; p = 5.09E-04). Fruit intake was also associated with a decreased risk of neuroticism traits related to depression, including feeling lonely (OR = 0.82, 95% CI = 0.74-0.90; p = 2.91E-05), feeling miserable (OR = 0.79, 95% CI = 0.72-0.87; p = 2.35E-06), feeling fed-up (OR = 0.75, 95% CI = 0.68-0.83; p = 2.78E-08), irritable mood (OR = 0.89, 95% CI = 0.79-0.99; p = 0.03), and neuroticism (OR = 0.85, 95% CI = 0.76-0.96; p = 9.94E-03). The causal relationship between feeling lonely and fruit intake was bidirectional.

Conclusion

Increased fruit intake has a causal effect in reducing the risk of depression and is beneficial for related psychological well-being.

A longitudinal analysis of Australian women's fruit and vegetable consumption and depressive symptoms

BACKGROUND

In Australia, women report higher rates of depressive symptoms than men. Research suggests that dietary patterns rich in fresh fruit and vegetables could protect against depressive symptoms. The Australian Dietary Guidelines suggest that consuming two servings of fruit and five serves of vegetables per day is optimal for overall health. However, this consumption level is often difficult for those experiencing depressive symptoms to achieve.

AIMS

This study aims to compare diet quality and depressive symptoms in Australian women over time using (I) two serves of fruit and five serves of vegetables per day (FV7), and (ii) two serves of fruit and three serves of vegetables per day (FV5).

MATERIALS AND METHODS

A secondary analysis was conducted using data from the Australian Longitudinal Study on Women's Health over 12 years at three time points 2006 (n = 9145, Mean age = 30.6, SD = 1.5), 2015 (n = 7186, Mean age = 39.7, SD = 1.5), and 2018 (n = 7121, Mean age = 42.4, SD = 1.5).

RESULTS

A linear mixed effects model found, after adjusting for covarying factors, a small significant inverse association between both FV7 (b = -.54, 95% CI = -.78, -.29) and FV5 (b = -.38, 95% CI = -.50, -.26) in depressive symptoms.

DISCUSSION

These findings suggest an association between fruit and vegetable consumption and decreased depressive symptoms. The small effect sizes indicate caution should be taken in interpreting these results. The findings also suggest that current Australian Dietary Guideline recommendations need not be prescriptive to two fruit and five vegetables for impact on depressive symptoms.

CONCLUSIONS

Future research could evaluate reduced vegetable consumption (three serves per day) in identifying the protective threshold for depressive symptoms.

Exploring an Artificial Intelligence–Based, Gamified Phone App Prototype to Track and Improve Food Choices of Adolescent Girls in Vietnam: Acceptability, Usability, and Likeability Study

Background

Adolescents’ consumption of healthy foods is suboptimal in low- and middle-income countries. Adolescents’ fondness for games and social media and the increasing access to smartphones make apps suitable for collecting dietary data and influencing their food choices. Little is known about how adolescents use phones to track and shape their food choices.

Objective

This study aimed to examine the acceptability, usability, and likability of a mobile phone app prototype developed to collect dietary data using artificial intelligence–based image recognition of foods, provide feedback, and motivate users to make healthier food choices. The findings were used to improve the design of the app.

Methods

A total of 4 focus group discussions (n=32 girls, aged 15-17 years) were conducted in Vietnam. Qualitative data were collected and analyzed by grouping ideas into common themes based on content analysis and ground theory.

Results

Adolescents accepted most of the individual- and team-based dietary goals presented in the app prototype to help them make healthier food choices. They deemed the overall app wireframes, interface, and graphic design as acceptable, likable, and usable but suggested the following modifications: tailored feedback based on users’ medical history, anthropometric characteristics, and fitness goals; new language on dietary goals; provision of information about each of the food group dietary goals; wider camera frame to fit the whole family food tray, as meals are shared in Vietnam; possibility of digitally separating food consumption on shared meals; and more appealing graphic design, including unique badge designs for each food group. Participants also liked the app’s feedback on food choices in the form of badges, notifications, and statistics. A new version of the app was designed incorporating adolescent’s feedback to improve its acceptability, usability, and likability.

Conclusions

A phone app prototype designed to track food choice and help adolescent girls from low- and middle-income countries make healthier food choices was found to be acceptable, likable, and usable. Further research is needed to examine the feasibility of using this technology at scale.

Frequency of fruit consumption and savoury snacking predict psychological health; selective mediation via cognitive failures

While there is growing interest in the link between diet and psychological health, there is a surprising lack of studies investigating the precise associations between nutrient-rich foods (such as fruit and vegetables) versus nutrient-poor foods (such as energy-dense savoury and sweet snacks), and psychological health. Similarly, the psychological processes underpinning the relationship between dietary intake and psychological health remain unclear. Hence, the present study aimed to explore the relationship between dietary consumption and psychological health, with cognitive processes as a theoretical mediator. This cross-sectional online study included 428 healthy adults (53% female; mean age= 39.7, SD= 13.0), with participants completing a range of validated questionnaires measuring dietary habits and psychological health. Stepwise multiple regression revealed that more frequent consumption of fruit was associated with reduced symptoms of depression (β = -.109, p = 0.025) and greater positive psychological wellbeing (β = .187, p < 0.001). Conversely, more frequent savoury snacking was associated with increased anxiety (β = .127, p = 0.005). Further, mediation analyses revealed that more frequent consumption of savoury snacks was associated with increased symptoms of depression, stress, anxiety, and reduced psychological wellbeing, via an increase in cognitive failures (ps < 0.001). These results provide new insights on the independent associations between certain types of food and psychological health, and the psychological mechanisms that may mediate these. Further work is now required to establish causality and determine whether these may represent modifiable dietary targets that can directly (and indirectly) influence our psychological health.

Lifestyle factors and psychological well-being: 10-year follow-up study in Lithuanian urban population

Background

Several lifestyle behaviours, including physical activity, smoking, alcohol consumption, nutrition habits, and social activity have been associated with psychological well-being (PWB). However, their effect on PWB prospectively has been less studied. The aim of the present study was to evaluate the influence of lifestyle factors on higher future PWB during the 10-year follow-up of middle-aged and elderly urban population.

Methods

In the baseline survey (2006 to 2008), 7115 men and women 45–72 years of age were examined within the framework of the international study Health, Alcohol and Psychosocial Factors in the Eastern Europe (HAPIEE). In the follow-up survey (in 2016), which was performed among all 6210 participants who survived till that year, 4266 individuals participated responding to postal questionnaires. PWB was assessed by a CASP-12 questionnaire. The lifestyle behaviours, including smoking and nutrition habits, alcohol consumption, social and physical activity, were evaluated by the questionnaire. Multivariable logistic regression models were applied for statistical data analysis.

Results

After accounting for several potential confounders, healthy levels of lifestyle behaviours were associated with higher PWB after 10-year follow-up. Never-smokers in men and former smokers in women had higher PWB by 43 and 67% odds respectively in comparison with smokers. Physical activity in women and high social activity both in men in women was positively related to higher PWB. More frequent fresh vegetable and fruit consumption was associated with higher odds of higher PWB (odds ratio 1.57 in men and 1.36 in women, p < 0.05) compared to less frequent consumption of such food groups. Dose-response relationship between increasing number of healthy lifestyle factors and higher PWB was determined both in men and women.

Conclusions

Lifestyle factors such as never smoking and former smoking, high social activity, and more frequent fresh vegetable and fruit consumption increased the odds of higher PWB over 10 years of follow-up in men and women groups. The increase of the protective health behaviour score was directly associated with the odds of higher PWB.

Consumption of Dietary Guidelines for Americans types and amounts of vegetables increases mean Subjective Happiness Scale scores: A randomized controlled trial

BACKGROUND

The health benefits of diets rich in fruits and vegetables (FV) are well established. Recent observational and intervention research suggests that FV consumption may also exert a positive effect on psychological well-being.

OBJECTIVE

This study aimed to assess changes in mean Subjective Happiness Scale (SHS) scores in response to consuming DGA recommended types and amounts of vegetables. It was hypothesized that increased vegetable consumption would increase mean SHS scores.

DESIGN

This study investigated a secondary outcome of a randomized, parallel, non-blinded controlled trial with a 1:1 allocation ratio to a provided vegetable intervention or attention control group.

PARTICIPANTS/SETTING

Men and women (n=75) aged 18-65 years, body mass index ≥25 kg/m², with low habitual vegetable consumption were recruited from Grand Forks, ND, December 2016 to January 2018, for this community-based study.

INTERVENTION

The vegetable intervention consisted of an 8-week feeding phase during which participants were provided with vegetables in DGA recommended types and amounts. The attention control group was not provided vegetables but completed the same testing schedule as the vegetable intervention group.

MAIN OUTCOME MEASURE

Mean SHS scores were assessed before and after the intervention.

STATISTICAL ANALYSES

Mean SHS scores were analyzed using a 2-way factorial mixed linear model analysis of variance.

RESULTS

A significant interaction between treatment and visit (P=0.015) revealed greater mean SHS scores at week 8 than at baseline in the vegetable intervention group (+0.23 ± 0.11 (mean difference ± standard error of the difference) but no change in the attention control group (-0.15 ± 0.11).

CONCLUSIONS

Greater mean SHS scores were observed after increasing vegetable consumption to meet DGA recommendations, suggesting that adhering to DGA vegetable guidance may help promote psychological well-being.

Applying the Stages of Change Model in a Nutrition Education Programme for the Promotion of Fruit and Vegetable Consumption among People with Severe Mental Disorders (DIETMENT)

Despite growing evidence of the benefits of adequate intake of fruit and vegetables (F&V) and the recommendation to consume five servings daily, the adoption of these habits is poor among people with severe mental disorder (SMD). The main aim of the present study is to determine changes in the intake of F&V and motivation to do so among people with SMDs after participating in a food education programme. A community-based randomized controlled trial was conducted in Spain, with the intervention group (IG) participating in a food education programme based on the stages of change model to promote consumption of F&V and the control group (CG) receiving three informative sessions on basic healthy eating. The main outcomes were related to the intake of F&V and stages of change. Data collection was performed at baseline, post intervention, and 12-month follow-up. Seventy-four participants enrolled in the study and sixty completed the 12-month follow-up. An increase in motivation towards the intake of F&V was observed in the IG but not in the CG (McNemar’s test p = 0.016, p = 0.625). No significant difference was observed for the intake of fruit, vegetables, or F&V. Basing food education strategies on the stages of change model shows positive results, increasing the awareness and disposition of people with SMD towards the intake of F&V. More research is needed to identify the most appropriate eating intervention to increase the intake of F&V.

Dietary, physical exercises and mental stress in a Chinese population: a cross-sectional study

Background

Mental health is affected by both genetic and environmental factors. However, previous studies have showed conflict findings about the role of lifestyle and little is known about the situation of the Chinese population. The purpose of this study was to explore the relationship between the frequency of food consumption, physical exercise condition and mental health, as well as factors related to mental stress in Chinese.

Methods

We recruited 8160 residents who had health examinations in a public hospital during June 2016 to May 2018. Demographic characteristics, the frequency of food consumption, physical exercise condition and mental health status was collected by a questionnaire. We estimated the association using the odds ratio (OR) and 95% confidence interval (CI) based on Binary or ordinal logistic regression models. A classification and regression tree (CART) demonstrated the prediction of the value of a target variable based on other values.

Results

The logistic regression model and classification tree model both found that the frequency of fresh vegetables or fruit and fried foods consumption and the current state of drinking alcohol were related to mental stress. The degree of mental stress reduced significantly with increasing consumption of fish (OR = 0.80, 95% CI: 0.71–0.90) and regular exercise (OR = 0.55, 95% CI:0.48–0.64) in females and increased consumption of fish (OR = 0.55, 95% CI: 0.48–0.64) and cereal crop (OR = 0.77, 95% CI: 0.68–0.89), fish (OR = 0.87, 95%CI:0.77–0.96) and regular exercise (OR = 0.61, 95%CI:0.53–0.70) in males. On the contrary, the frequency of consumption of desserts (OR = 1.43, 95% CI: 1.26–1.62) and the current of drinking alcohol (OR = 1.47, 95%CI:1.21–1.79) in females and meat (OR = 1.47, 95%CI: 1.31–1.65), pickled and smoked food (OR = 1.18, 95%CI:1.05–1.32) and the current state of drinking alcohol (OR = 1.25, 95%CI:1.12–1.40) in males were related to an increased risk of mental health.

Conclusions

Our study showed that both the frequency of some food consumption and physical exercise condition were associated with mental health and affected the degree of stress, which provided novel insights into interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11189-7.

Association of a Mediterranean Diet and Fruit and Vegetable Consumption with Subjective Well-Being among Adults with Overweight and Obesity

Recent evidence suggests that among behavioral-lifestyle factors, adherence to a healthy dietary pattern such as the Mediterranean Diet (MedDiet) is linked not only to better psychological health and mental positive status but also to increased subjective well-being (SWB). Nevertheless, this association has been unexplored among individuals with excessive weight. This study explored whether adherence to the MedDiet and the intake of healthy foods such as fruits and vegetables (FV) are associated with increased happiness and life satisfaction among Spanish adults with overweight or obesity when weight, body image, and body satisfaction are also considered. A convenience sample of adult individuals with excessive weight completed self-reports on the study variables, and weight and BMI were measured by bioimpedance. No evidence of a relationship with SWB indicators was obtained for MedDiet global indicators, probably due to the low adherence to a healthy diet by these individuals. In contrast, FV intake, as a powerful indicator of healthy eating, was associated with life satisfaction when BMI and body image dimensions were considered, among which body satisfaction had a key role. Moreover, life satisfaction fully mediated the relationship between FV consumption and happiness. Our findings are expected to make a relevant contribution to knowledge on the positive correlates or protective factors for overall well-being in obesity, including dietary habits and body appreciation. Our results may inform obesity management actions focused on inclusive, positive aesthetic models and promoting a healthy lifestyle for happiness in obesity.

Addressing the COVID-19 Mental Health Crisis: A Perspective on Using Interdisciplinary Universal Interventions

Mental health is reaching a crisis point due to the ramifications of COVID-19. In an attempt to curb the spread of the virus and circumvent health systems from being overwhelmed, governments have imposed regulations such as lockdown restrictions and home confinement. These restrictions, while effective for infection control, have contributed to poorer lifestyle behaviors. Currently, Positive Psychology and Lifestyle Medicine are two distinct but complimentary disciplines that offer an array of evidence-based approaches for promoting mental health and well-being across a universal population. However, these strategies for improving mental health are typically used in isolation. This perspective calls for a new paradigm shift to create and rollout well-designed interdisciplinary universal multicomponent mental health interventions that integrates the benefits of both disciplines, and uses innovative digital mental health solutions to achieve scalability and accessibility within the limitations and beyond the COVID-19 lockdown and restrictions.

Association of home cooking with caregiver-child interaction and child mental health: results from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study

OBJECTIVE

To examine the associations of home cooking with caregiver-child interaction and child mental health in Japan.

DESIGN

Cross-sectional data collected in 2018. Frequency of home cooking was assessed by a questionnaire among 4126 caregivers and classified as high (almost every day), medium (4-5 d/week) or low (≤3 d/week). Caregiver-child interaction was evaluated by assessing frequency of talking and playing together (per week). Behaviour problems and prosocial behaviour were assessed by the Strengths and Difficulties Questionnaire, and resilience was assessed using the Children's Resilient Coping Scale.

SETTING

Japan.

PARTICIPANTS

Children aged 9-10 years and their caregivers in Adachi, Tokyo, Japan.

RESULTS

Low and middle frequency of home cooking were associated with lower frequencies of talking about school life, talking about news with the child, talking about television shows with the child and helping with the child's homework. Children with low and/or middle frequency of home cooking had more behaviour problems (low frequency: β = 3·95, 95 % CI 1·30, 6·59 and medium frequency: β = 3·38, 95 % CI 2·07, 4·70), lower prosocial behaviour (low frequency: β = -5·85, 95 % CI -10·04, -1·66) and lower resilience (low frequency: β = -6·56, 95 % CI -9·77, -3·35 and medium frequency: β = -4·11, 95 % CI -5·71, -2·51), compared with children with high frequency of home cooking after adjusting covariates including socio-economic status. These associations were mediated by child's eating behaviours and/or caregiver-child interaction.

CONCLUSIONS

Creating an environment that encourages caregivers to cook at home may be important for children's mental health.

Impact of review method on the conclusions of clinical reviews: A systematic review on dietary interventions in depression as a case in point

Background

The recommendations of experts who write review articles are a critical determinant of the adaptation of new treatments by clinicians. Several types of reviews exist (narrative, systematic, meta-analytic), and some of these are more vulnerable to researcher bias than others. Recently, the interest in nutritional interventions in psychiatry has increased and many experts, who are often active researchers on this topic, have come to strong conclusions about the benefits of a healthy diet on depression. In a young and active field of study, we aimed to investigate whether the strength of an author’s conclusion is associated with the type of review article they wrote.

Methods

Systematic searches were performed in PubMed, Web of Science, Cochrane Database of Systematic Reviews, and Google Scholar for narrative reviews and systematic reviews with and without meta-analyses on the effects of diet on depression (final search date: May 30^th, 2020). Conclusions were extracted from the abstract and discussion section and rated as strong, moderate, or weak by independent raters who were blind to study type. A benchmark on legitimate conclusion strength was based on a GRADE assessment of the highest level of evidence. This systematic review was registered with PROSPERO, number CRD42020141372.

Findings

24 narrative reviews, 12 systematic reviews, and 14 meta-analyses were included. In the abstract, 33% of narrative reviews and 8% of systematic reviews came to strong conclusions, whereas no meta-analysis did. Narrative reviews were 8.94 (95% CI: 2.17, 36.84) times more likely to report stronger conclusions in the abstract than systematic reviews with and without meta-analyses. These findings were similar for conclusions in the discussion section. Narrative reviews used 45.6% fewer input studies and were more likely to be written by authors with potential conflicts of interest. A study limitation is the subjective nature of the conclusion classification system despite high inter-rater agreements and its confirmation outside of the review team.

Conclusions

We have shown that narrative reviews come to stronger conclusions about the benefits of a healthy diet on depression despite inconclusive evidence. This finding empirically underscores the importance of a systematic method for summarizing the evidence of a field of study. Journal editors may want to reconsider publishing narrative reviews before meta-analytic reviews are available.

Intakes of Specific Categories of Vegetables and Fruits Are Inversely Associated With Depressive Symptoms Among Adults

BACKGROUND

Epidemiological evidence on the relationships between intakes of different categories of vegetables and fruits and depressive symptoms is very limited and inconsistent, especially with no evidence from the general population. This study aimed to estimate their relationships among a large general population.

METHODS

The cross-sectional design was based on the National Health and Nutrition Examination Survey (2007-2014) and included 16,925 adults. Dietary information was attained from two nonconsecutive 24-hr dietary recalls. Patient Health Questionnaire was applied for measuring depressive symptoms. The associations between vegetables and fruits intakes and depressive symptoms were appraised utilizing logistic regression and restricted cubic spline.

RESULTS

Compared with the lowest category of intake, the most-adjusted odds ratios of depressive symptoms for the highest intake category of tomatoes and tomato mixtures were 0.81 (95% confidence interval [CI], 0.66-0.99), and 0.64 (95% CI, 0.48-0.85) for dark-green vegetables, 0.67 (95% CI, 0.53-0.84) for other vegetables, 0.48 (95% CI, 0.29-0.79) for berries, 0.67 (95% CI, 0.55-0.82) for total vegetables, and 0.70 (95% CI, 0.57-0.86) for total fruits, and for the medium categories of bananas and dried fruits were 0.62 (95% CI, 0.41-0.95) and 0.39 (95% CI, 0.19-0.81), respectively. After sensitivity analysis further excluding subjects with co-morbid health conditions, these findings remained significant, except for bananas. An L-shaped relationship was observed between depressive symptoms and intake of total vegetables, while the association was linear with total fruits intake.

CONCLUSIONS

Intakes of tomatoes and tomato mixtures, dark-green vegetables, other vegetables, berries, dried fruits, total vegetables, and total fruits were inversely related to depressive symptoms among adults.

Fruit and Vegetable Intake and Mental Health in Adults: A Systematic Review

The role of a properly balanced diet in the prevention and treatment of mental disorders has been suggested, while vegetables and fruits have a high content of nutrients that may be of importance in the case of depressive disorders. The aim of the study was to conduct a systematic review of the observational studies analyzing association between fruit and vegetable intake and mental health in adults. The search adhered to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42019138148). A search for peer-reviewed observational studies published until June 2019 was performed in PubMed and Web of Science databases, followed by an additional manual search for publications conducted via analyzing the references of the found studies. With respect to the intake of fruit and/or vegetable, studies that assessed the intake of fruits and/or vegetables, or their processed products (e.g., juices), as a measure expressed in grams or as the number of portions were included. Those studies that assessed the general dietary patterns were not included in the present analysis. With respect to mental health, studies that assessed all the aspects of mental health in both healthy participants and subjects with physical health problems were included, but those conducted in groups of patients with intellectual disabilities, dementia, and eating disorders were excluded. To assess bias, the Newcastle-Ottawa Scale (NOS) was applied. A total of 5911 studies were independently extracted by 2 researchers and verified if they met the inclusion criteria using a 2-stage procedure (based on the title, based on the abstract). After reviewing the full text, a total of 61 studies were selected. A narrative synthesis of the findings from the included studies was performed, which was structured around the type of outcome. The studies included mainly focused on depression and depressive symptoms, but also other characteristics ranging from general and mental well-being, quality of life, sleep quality, life satisfaction, flourishing, mood, self-efficacy, curiosity, creativity, optimism, self-esteem, stress, nervousness, or happiness, to anxiety, minor psychiatric disorders, distress, or attempted suicide, were analyzed. The most prominent results indicated that high total intake of fruits and vegetables, and some of their specific subgroups including berries, citrus, and green leafy vegetables, may promote higher levels of optimism and self-efficacy, as well as reduce the level of psychological distress, ambiguity, and cancer fatalism, and protect against depressive symptoms. However, it must be indicated that the studies included were conducted using various methodologies and in different populations, so their results were not always sufficiently comparable, which is a limitation. Taken together, it can be concluded that fruits and/or vegetables, and some of their specific subgroups, as well as processed fruits and vegetables, seems to have a positive influence on mental health, as stated in the vast majority of the included studies. Therefore, the general recommendation to consume at least 5 portions of fruit and vegetables a day may be beneficial also for mental health.

Vegetable Consumption and Factors Associated with Increased Intake among College Students: A Scoping Review of the Last 10 Years

Vegetable consumption is a predictor for improved health outcomes, such as reduced obesity and likelihood of food-related noncommunicable diseases. Young adults are a key population, being in a transitional stage-of-life: Habits gained here are taken through the lifespan. This review establishes insight into the consumption of vegetables among young adults during their college/university years, and factors associated with increased consumption. Seventy-one papers were extracted, published between January 2009 and October 2018. Search terms related to consumption; vegetables; and college/university setting and sample. A diverse range of definitions, guidelines, and study approaches were observed. Findings identify that the majority of students do not consume World Health Organization recommendations. Being female was the most frequent predictor of higher intake of vegetables, and no consumption patterns were identified by countries. Living at family home; body mass index; happiness and stress level; perceived importance of healthy eating; socioeconomic level; breakfast consumption; stage of study; openness to new experiences; sleep pattern; nutrition knowledge; activity level; alcohol usage; and energy intake were identified as influential factors. Public policies and new strategies to encourage vegetable consumption among college students are indispensable, especially targeting subgroups with even lower intakes, such as males and those living outside family home.