Mental health disorders are the leading cause of ill-health and disability, with depression and anxiety being among the most prevalent(1). There is a growing body of evidence to indicate that optimal nutrition can help to promote better mental health, while suboptimal dietary patterns or status of specific nutrients have been associated with a greater risk of depression and anxiety, but the evidence is conflicting(2,3,4,5). Therefore, the aim was to conduct a systematic review with metaanalyses to investigate the effect of interventions with specific nutrients or dietary patterns on mental health outcomes in adults.

Searches were conducted using the electronic bibliographic databases: MEDLINE, EMBASE and PsycINFO. The inclusion criteria were randomised controlled trials or controlled dietary interventions; study duration ≥ 12 weeks; participants aged ≥ 18 years old; outcome measures of depression or anxiety. The meta-analysis was conducted using Cochrane Review Manager Software (RevMan), version 5.4. The Risk of Bias and Quality of Evidence were assessed utilising the Cochrane Risk of Bias 2 tool and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework, respectively.

A total of 68 studies met the inclusion criteria: 5 investigated dietary patterns, while 63 were nutrient interventions, involving omega-3 (n = 22), vitamin D (n = 18), B-vitamins (n = 10), zinc (n = 7), iron (n = 1), vitamin D combined with calcium (n = 4), and omega-3 combined with vitamin D (n = 1). Insufficient studies were available to conduct a meta-analysis for any nutrient in relation to anxiety; all results relate to depression. Meta-analysis results showed that zinc intervention significantly reduced depression (standardised mean difference (SMD) in depression scores was −0.67; 95% Confidence Interval (95% CI) −0.96, −0.37); 4 studies, GRADE: moderate certainty). No significant effects on depression were reported in response to intervention with omega-3 fatty acids [SMD 0.26 (95% CI −0.64, 0.12); 10 studies, GRADE: moderate certainty] or vitamin D [SMD 0.07 (95% CI 0.34, 0.47); 10 studies, GRADE: moderate certainty], while there were insufficient studies to perform a meta-analysis for B-vitamins and depression. There was also no significant effect of the Mediterranean Diet on depression [SMD −0.95 (95% CI -1.90, 0.01); 3 studies, GRADE: high certainty], and insufficient studies for analysis of the Dietary Approaches to Stop Hypertension (DASH) diet.

The results indicate that zinc supplementation has beneficial effects on depression, but there were no significant effects of intervention with the Mediterranean Diet, omega-3 fatty acids or vitamin D. These meta-analyses are however based on a limited number of intervention studies and therefore no firm conclusions can be reached. Further intervention trials are required to fully investigate the effects of specific nutritional factors on mental health.

Plant-based foods encompass all food products derived from plant sources, such as fruits, vegetables, grains, legumes, herbs and spices, and nuts and seeds, plant-based fats and oils (e.g. olive oil) and plant-based beverages (e.g. tea and coffee). Consumption of diverse plant-based foods is a dietary pattern that has gained significant attention amongst the public, due to its perceived benefits for maintenance of health(1). Plant-based foods provide a rich source of macronutrients, micronutrients and non-nutrient bio-actives that are often reported to improve health outcomes. Despite this, there are no standard definitions of plant-based diversity, or consensus on methods of measurement in nutrition research studies. The objective of the current research was to conduct a scoping review of the literature to identify studies investigating plant-based food diversity and it’s impact on human health outcomes, and to subsequently characterize a) definitions of plant-based diversity used, b) methods used to assess plant-based food intake, c) methods used to assess plant- based food diversity, and d) health outcomes assessed and key findings.

Eligible studies were those investigating the relationship or impact of plant-based food diversity on any health related or lifestyle outcome, by any study design, in high income countries only. Studies were identified by systematic searches of two electronic databases and manual searches of reference lists. No restrictions were applied for language or year of publication. The review was performed in line with the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (2).

Forty-four studies were eligible for inclusion in this review. The majority of studies were observational in design (39/44; 87%) and included fruits and vegetables only in their definitions of plant-based food diversity (32/44, 72%). Methods of measurement of both plant-based food intake and diversity varied greatly among studies, with only four studies (9%) utilizing a tool validated for assessment of plant-based food diversity in their population of interest. Health outcomes included dietary intake and behaviour, socioeconomic factors, cardiometabolic risk factors, and cancer risk,. No randomized controlled trials investigating the impact of plant food diversity on health outcomes were identified.

There is a need for a consensus definition of “diverse plant-based foods” incorporating all relevant foods from plant sources (e.g. legumes, nuts, herbs). Robust measurement tools and reporting guidelines for the assessment of plant-based food diversity in nutrition research studies will help to standardize research in this area. Within countries, an assessment of standard levels of intake of plant-based foods would be beneficial, in identifying whether diverse plant-based eating may be a target for dietary improvement. Observational studies report associations between plant-based food diversity and health outcomes, that warrant investigation in future randomized controlled trials.

There is evidence for associations between polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and psychosis risk(1–3). However, the existing literature has focused on PUFA measurements at single timepoints(4,5), which may overlook dynamic patterns of variability over time. The aims of this study were: 1) To describe longitudinal trajectories of plasma omega6:omega-3 ratio and DHA in a large general population sample; and 2) To evaluate associations between trajectories and psychosis-spectrum outcomes in early adulthood.

We performed a cohort study within the Avon Longitudinal Study of Parents and Children. 3635 participants completed psychiatric assessments at age 24 years (2247 [61.8%] female). Participants provided plasma samples at four timepoints when aged 7, 15, 17 and 24. Plasma omega-6:omega-3 ratio and DHA levels (% total fatty acids) were measured using nuclear magnetic spectroscopy, then standardised by sex.

Psychosis-spectrum outcomes were assessed at age 24. Psychotic experiences (PEs) and psychotic disorder were assessed using the Psychosis-Like Symptoms interview (PLIKSi), as was the total number of PEs (range 0 to 11). Negative symptoms score (range 0 to 10) was measured using the Community Assessment of Psychic Experiences.

Curvilinear growth mixture modelling was used to derive longitudinal trajectories of plasma omega-6:omega-3 ratio and DHA levels over time. Trajectories were adjusted contemporaneously for body mass index at each timepoint. Associations between trajectory membership and outcomes were adjusted for sex, ethnicity, parental socioeconomic class, smoking and alcohol use.

A three-trajectory solution was optimal for omega-6:omega-3 ratio (stable average, n = 3282 [90.3%]; slightly above average, n = 61 [1.7%]; and persistently high, n = 292 [8.0%]) and DHA (stable average, n = 2739 [75.4%]; persistently high, n = 245 [6.7%]; and persistently low, n = 651 [17.9%]).

Relative to stable average, trajectories characterised by persistently high omega-6:omega-3 ratio and persistently low DHA were associated with increased odds of PEs and psychotic disorder in unadjusted analyses, but these associations attenuated on adjustment for covariates. Conversely, the persistently high omega-6:omega-3 ratio trajectory was associated with increased number of PEs (adjusted β 0.41, 95% confidence interval [CI] 0.05−0.78, p = 0.026) and negative symptoms (adjusted β 0.43, 95%CI 0.14−0.72, p = 0.004). Similarly, the persistently low DHA trajectory was also significantly associated with increased number of PEs (adjusted β 0.45, 95%CI 0.14−0.76, p = 0.004) and negative symptoms (adjusted β 0.35, 95%CI 0.12−0.58, p = 0.003).

Persistently high plasma omega-6:omega-3 ratio and persistently low plasma DHA were associated with increased PEs and negative symptoms of psychosis at age 24. Optimisation of PUFA status during development warrants further investigation in relation to psychosis-spectrum outcomes in early adulthood. Limitations include that causality cannot be inferred and residual confounding is possible. Attrition occurred along a socioeconomic gradient, although we used multiple imputation to avoid complete-case biases. Strengths include the use of a wellcharacterised cohort, and the use of biomarker measurement of plasma PUFAs.

Establishing healthy lifelong eating habits in young people is important for short and long-term health(1). Schools are ideal setting to improve diet. However, research shows that many school food environments are unhealthy(2). In New Zealand (NZ), the canteen is a popular food provision, particularly in secondary schools. This research aimed to explore the barriers and enablers to providing healthy food and beverages in NZ secondary school canteens. In 2022, 6 secondary schools were purposively selected to participate in semi-structured interviews about foods and beverages sold in schools’ canteens and the factors that influenced this. In total, 11 stakeholders representing six schools and one staff member of an external catering company completed interviews. The interviews were transcribed and analysed using a reflexive thematic analysis approach(3). Four themes were developed. Theme 1 Action-oriented school policies that are based on healthy eating principles can facilitate healthier canteens highlighted the use and characteristics of policies. The subtheme highlighted that Mandatory policies are more enforceable. Theme 2 Multiple component opt-in programs or interventions facilitate a healthier school food provision shows that opt-in government interventions (e.g. Ka Ora, Ka Ako, the NZ free school lunch initiative) with funding, monitoring, and incentives can improve food provision. The subtheme Health-enhancing changes in the school environment has flow-on effect to canteens showed that these changes can affect the entire school food environment. Theme 3 Healthy canteens get lost in the “pecking order” of what’s important highlights that while schools and key stakeholders may believe healthy eating is important, other factors related to well-being and education were more important to prioritise within the school’s limited resources. Theme 4 People’s values, attitudes and beliefs may help and hinder the healthiness of canteens and explores the role champions have in influencing the healthiness of the canteen. Champions were those with a positive, proactive attitude, value healthy eating and are capable. Subtheme 1 Meet student preferences while providing healthy food was a common barrier many champions worked hard to overcome. The final subtheme identified how A collaborative approach within schools and their communities can overcome barriers to healthy canteens. Government mandates and interventions can positively impact the canteen and other food provisions. This research supports a recommendation for schools to create and implement school policies around food encompassing a whole-school approach.

Restriction of energy intake is an effective strategy for achieving body mass loss(1). However, it leads to gastrointestinal appetite hormonal changes, which are expected to enhance hunger, reduce satiety, and possibly impair the ability to comply with prescribed intervention(2). Exercise interventions, on the other hand, did not modify gastrointestinal appetite hormones(3) and there is some evidence that postprandial appetite hormone responses after a low carbohydrate-high fat meal (LCHF) are more favorable than after high carbohydrate-low fat meal (HCLF) meal (4). This study investigated how energy-restricted diets based on LCHF and HCLF meals and combined with exercise affect body weight, and gastrointestinal appetite hormones and explored the relationship between body mass changes and changes in gastrointestinal appetite hormones.

Twenty-seven overweight and obese females (age: 35 ± 9.35 years, BMI: 31.64 ± 5.08 kg/m2) completed a randomized parallel design study and underwent a 4-week intervention consisting of brisk walking combined with either consumption of calorie-restricted HCLF or LCHF diet. Participants underwent a 5-hour experimental trial before and after the interventions, which included body weight measurements and fasting and postprandial blood sample collection for gastrointestinal appetite hormone measurements.

Both interventions significantly reduced body mass (HCLF group, −2.1 ± 1.7 Kg: LCHF group, -1.7 ± 1.7 Kg, P < 0.05 for both groups), but changes between the groups were not significant (P>0.05). Body mass changes were individual and ranged from -0.4 kg to −5.3 kg and from +1 kg to −4.4 kg in the HCLF and LCHF groups, respectively. The interventions had no impact on mean values of time- averaged postprandial concentrations of ghrelin, PYY, and GLP-1 but there was large individual variability in changes of these hormones. Results combined from both groups revealed that changes in ghrelin ranged from +549.3 to -407.7 pg/ml, in PYY from −132.5 to + 96.4 pg/ml and in GLP-1 from −6.6 to +19.5 pg/ml. Correlation, investigated on the data from both groups combined, between changes in body mass and changes in ghrelin (r = −0.18, P= 0.41), PYY (r = −0.04, P =0.87), and GLP-1 (r = 0.11, P = 0.64) were not significant.

In conclusion, the extent of body mass loss during interventions based on restricted energy intake diets combined with exercise is not related to the carbohydrate and fat content of the diet. Our findings also suggest that the success of body mass loss cannot be predicted by changes in postprandial concentrations of gastrointestinal appetite hormones.

School-provided lunch programs offer numerous benefits to primary school students including improved school attendance and performance, reduced undernutrition, reduced food insecurity, the opportunity to learn healthy eating, and the development of healthy dietary habits(1–3). Australia does not have an ongoing national school-provided lunch program that provides food for all students. To successfully implement a school-provided lunch program in Australian primary schools, it is essential to obtain the opinions of all key stakeholders, including parents. This study aimed to examine Victorian primary school parents’ opinions about a potential school-provided lunch program. An online cross-sectional survey with open- and closed-ended questions was conducted in Victoria, Australia, in 2022. Descriptive statistics and chi-square analyses were performed using SPSS software; thematic analysis was carried out using NVivo. Three hundred and fifty-nine parents responded to the survey. Fifty-seven percent of respondents said they would allow their child to participate in a school-provided lunch program, 34% were unsure and only 9% said they would not. The opportunity for hot-cooked lunches at school and the perceived convenience for parents were the top two reasons for favouring such a program. Fifty-eight percent were in favour of hybrid-type funding from both the government and parents, while 30% were in favour of being fully funded by the government. The most preferred amount to pay per meal was AUD5-6 (43%), followed by AUD3-4 (25%). When respondents were asked to rate the importance of six options in school-provided lunches (vegetarian, nut-free, dairy-free, gluten-free, egg-free, and vegan options), almost one-third of them selected having ‘vegetarian’ options as important or very important, whilst one-fifth selected ‘nut-free’, ‘dairy-free’, and ‘gluten-free’ options as important or very important. There were no associations between the parents’ or children’s socio-demographic characteristics and the likeliness of letting their children use school-provided lunches, funding preference, the amount willing to pay for school lunches, and the importance of different options. Respondents’ written responses revealed that they expected school-provided lunches to be healthy and made from whole food and cater to the special dietary and cultural needs of their children. Their other expectations included food being tasty and offered in a child-friendly way, having a variety of food offered, and having backup options if the children would/ could not eat those meals. They also expected enough time to be provided for eating lunches so children could eat and enjoy the meals. The findings of this study suggest that Victorian primary school parents are open to the idea of a school-provided lunch program, but they do have several expectations regarding the menu and time for eating. Program planners could use the findings of this study to create a school lunch program that aligns with the parents’ expectations and preferences.

Increasing evidence indicates that (poly)phenol consumption can have beneficial effects in human brain function(1). The overall aim of this project is to investigate whether consumption of a (poly)phenol rich cranberry drink improve mental health and cognitive function in university students via the gut-brain axis.

A parallel randomised controlled trial was conducted in 72 young healthy final year university students assigned to consume 236 mL cranberry drink (442 mg polyphenols) or nutrient matched placebo, daily for 12 weeks. The primary outcome was mood, measured as Total Mood Disturbance (TMD), using the Profile of Mood States (POMS) questionnaire. Secondary outcomes included stress, anxiety and depression levels, measured using the Perceived Stress Scale (PSS), and the Hospital Anxiety Depression Scale (HADS) questionnaire, salivary cortisol levels and cognitive function measured using the Online General Cognitive Assessment Battery (CogniFit). All of these questionnaires were measured every 4 weeks. Blood and urine samples were collected to measure inflammatory markers, gut-brain-axis metabolites, short chain fatty acids (SCFA), and cranberry polyphenols metabolites. Faecal samples were also collected for measuring gut microbiome diversity and composition and faecal metabolomics. Diet was assessed using food frequency questionnaires (FFQ), 7-day food diaries (EPIC) and 24 h online dietary recalls (intake 24) during the study. Linear mixed-effect model (LMM) and ANCOVA were used to investigate the relationship between the 2 trial arms.

No significant differences were found between treatments for mood, stress levels, anxiety, depression, circulating short chain fatty acids or inflammatory markers, however a significantly lower diurnal area under the curve of salivary cortisol (p = 0.010) and significantly higher short-term memory (Z-score: p = 0.024; Raw-score: p = 0.034) was found at 12 weeks in the cranberry group compared with the placebo. Besides, significant differences between interventions were found in plasma gut-brain axis metabolites, including the kynurenine and bile acids pathway which were kynurenine (p = 0.023), kynurenic (p = 0.032), quinolinic (p = 0.018), and glycolithocholic acid (p = 0.04) as well as several plasma and urinary cranberry (poly)phenol metabolites were modulated by cranberry consumption.

In conclusion, daily cranberry (poly)phenol supplementation for 12 week did not improve mood, stress, anxiety, and depression symptoms in healthy university students, however it may modulate cortisol levels and some aspects of cognitive function via the gut-brain axis.

There are known differences in biological functionality between vitamin D2 and D3. It is suspected from randomised control trial (RCT) data that vitamin D2 supplementation causes a reduction in serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations (1), but the size of the effect has yet to be fully assessed across multiple studies. The aim of this study was to undertake a systematic review and meta-analysis of the effect of vitamin D2 supplementation on serum 25(OH)D3 concentrations.

PUBMED was searched for publications from 1st January 1975 to 1st February 2023. Of the 182 papers retrieved, 29 were included in the systematic review, and of those, 18 were suitable for meta-analysis.

The meta-analysis found significant reductions in serum D3 after vitamin D2 supplementation compared with control, for both end of trial between groups data (weighted mean difference (WMD) (random) = −13.51 nmol/L; 95% CI: −20.14, −6.89; P < 0.0001) and absolute change over the trial (WMD (random) = −9.25 nmol/L; 95% CI: −14.40, −4.10; P = 0.0004). Similar results were found when D2 supplementation was compared to D3 supplementation, although as expected, the magnitude of the difference was larger, with WMD (random) = −46.20 nmol/L (95% CI: −60.80, −31.60; P < 0.00001) for end of trial data, and WMD (random) = −56.23 nmol/L (95% CI: -69.17, −43.28; P < 0.00001) for absolute change.

Overall, we found that vitamin D2 supplementation produces significant reductions in serum 25(OH)D3 concentrations, when compared to either control or vitamin D3 supplementation. An inverse relationship between vitamin D2 and D3 concentrations has been proposed in the literature (2). A regulatory mechanism that disposes of 25(OH)D after an increase in vitamin D concentrations could explain our results (3). Moreover, supplementation with vitamins D2 and D3 has differential effects on gene expression (4). However, longer-term research is needed to establish whether clinical advice should recommend vitamin D3 supplements over vitamin D2 supplements, where appropriate.

Most Australian school students take a packed lunch to school(1). However, parents have reported many barriers to packing a healthy lunch(2). Subsequently, foods eaten during school hours are not consistent with the Australian Dietary Guidelines, with discretionary foods providing about 44% of energy consumed during this time(3). In addition, some children go to school without any food for lunch or money to buy lunch. The Tasmanian School Lunch Project provides free nutritious cooked lunches for Kinder to Year 10 students attending 30 government schools (15 commenced 2022, 15 commenced 2023) in areas of high socioeconomic disadvantage. The lunches were provided 1-3 days/week. The menu and recipes were designed by dietitians. This analysis aimed to describe parents’ perceptions of the School Lunch Project during the first year. Six of the 15 schools that commenced in term 2 2022 were invited, and agreed, to participate in the evaluation. During term 3 or 4 2022, parents completed online or written surveys (n = 159) and/or participated in discussion groups (n = 26) to share their thoughts on the menu, their concerns, likes, and willingness to pay. Survey data were analysed descriptively and open-ended survey responses and discussion group data thematically. During 2022, 78,832 nutritious cooked lunches were provided to 1,678 students. Most parents felt there was enough variety on the menu (66%) and the right amount of food was served (69%). Most students (79%) ate the lunches every day they were provided yet 52% of parents continued to provide a packed lunch. Parents enjoyed that their child was having a healthy lunch (66%) and trying new foods (74%). Some parents in the discussion groups indicated positive flow on effects at home with students trying new foods and sitting down together as a family to eat the evening meal. Half the parents (50%) had no concerns about the school providing lunches. The most commonly reported concerns were their child might not like the food (36%) or their child does not try new foods (8.6%). These concerns were also raised in the discussion groups. Most parents (93%) were prepared to pay for the lunches in future (median $3, range $1-$12) and 85% thought there should be a family discount. Parents acknowledged some payment was necessary for the sustainability of the program but some expressed concern for those who may struggle to pay. More direct communication with families about the meals offered, the availability of bread (from term 4 2022) for students who choose not to eat the cooked lunch or want more to eat, and allowing families time to adjust to the new lunch system, may address some of the concerns raised. Further data on parents’ perceptions of the school lunches will be collected during term 3 2023.

Frailty is a distinctive health state related to the ageing process in which multiple body systems gradually lose their in-built reserves, and is associated with declines across sensory, neurological, cardiovascular, and musculoskeletal systems(1). Previously, relationships have been identified between high dietary nitrate intake and several components of frailty including muscle strength and cognitive function, as well as vascular disease(2). However, little is known about the relationship between dietary nitrate intake and frailty in older adults. We investigated if higher habitual nitrate intake, derived from plant (e.g., vegetables, grains, beans, and fruits) and animal foods (e.g., meats, cheese, yoghurt) was associated with frailty in older women.

1390 community-dwelling older women (mean age 75.1 ± 2.7 years) from the Perth Longitudinal Study of Ageing Women completed a validated semi-quantitative food frequency questionnaire (FFQ) at baseline (1998). Nitrate concentrations in food were obtained from our recently published international plant and animal nitrate databases and applied to each of the plant and animal foods within the FFQ (described in3). Frailty was operationalised using a standardised frailty index (FI) of cumulative deficits from 33 variables across multiple health domains (physical, mental, comorbidities), with a score ≥0.25 indicating frailty. Cross-sectional associations between dietary nitrate derived from plant and animal foods (separately) with frailty were analysed using multivariable-adjusted logistic regression models as part of restricted cubic splines. Models were adjusted for lifestyle and dietary factors (not used in the FI) that included age, smoking history, protein, alcohol, and energy intake.

Frailty was observed in 276 (19.9 %) women. Median (IQR) daily plant and animal nitrate were 72.1 (55.6-90.0) mg/day and 3.5 (2.2-5.1) mg/day, respectively. A significant non-linear relationship was observed between higher plant nitrate intake and frailty, with a nadir recorded once intakes of ~64 mg/day were achieved (median of quartile [Q]2). Specifically, compared to women with the lowest intake of plant-derived nitrate (Q1, median 45 mg/day), women in Q2 (OR 0.69 95%CI 0.56-0.84), Q3 (OR 0.67 95%CI 0.50-0.90) and Q4 (OR 0.66 95%CI 0.45-0.98) had lower odds for frailty (all p<0.05). Additional adjustment for diet quality (Nutrient Rich Food Index per 1000 kJ) or total plasma 25-hydroxyvitamin D did not alter the findings. Nitrate derived specifically from vegetables and grains were found to drive these results. No relationship was observed between animal-derived nitrate and frailty.

Community-dwelling older women consuming higher amounts of nitrate derived primarily from plants were less likely to present with frailty. Consuming 1-2 servings (75-150 g) per day of nitrate- rich green leafy vegetables, as part of total vegetable intake, will provide adequate nitrate levels (>70 mg/day) that could serve as a novel intervention to limit frailty.

Emerging evidence suggests protective properties of a Mediterranean diet (MD) in relation to prevention and management of mood disorders(1). However, there is paucity of dietary interventions investigating adherence to MD and effects on mood and wellbeing in individuals without a clinical diagnosis. The present study aimed to investigate the effects of adherence to a short-term MD on mood and wellbeing in healthy adults.

A controlled crossover design randomly assigned 18 adults (Age(yrs) 53.74 ( ± 7.10), BMI(kg.m2)26.62 ( ± 5.45)) to follow a MD or their habitual diet (control) for 7-days, before switching to the alternate condition (following a 7-day washout). At baseline, an Educational Group Session familiarised participants with MD principles through informal presentation and interactive explanation of participant resource booklets to use at home throughout the MD condition only. Anthropometric characteristics, self-reported mood (Profile of Mood States (POMS), Lader Visual Analogue Scale(VAS)) and wellbeing (Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) were assessed at baseline and upon completion of each diet condition. The MD Adherence Screener (MEDAS) assessed adherence to the interventions.

A significant difference was found in MD adherence scores between MD (M=11.3, SD=1.8) and Control Diet (CD) (M=2.5, SD=1.5); t(17)=16.1, p<0.001). Main effects analysis using a general linear model controlling changes in body mass index showed significant effects of MD intervention versus the CD on the change in total mood disturbance (M(MD)=−15, SD=12), M(CD)=−3, SD=9), F(1,31)=4.9, p=0.034); feelings of calm (VAS) (M(MD)=9, SD=14), M (CD)=−2, SD=6), F(1,31)=8.5, p=0.006); wellbeing (M(MD)=6, SD=5), M(CD)=−2, SD=6), (F(1,31)=6.6, p= 0.015).

These findings suggest that a short-term dietary change towards a MD can improve mood, feelings of calm and overall wellbeing in middle aged adults.

Chronic low-grade inflammation has been associated with poor mood states and reduced mental well-being, increasing the chances of comorbidities such as diabetes and mental illness (1). Inflammation and stress share a bi-directional relationship (2), impacting an individual’s mood and mental well-being. Whole food interventions such as the Mediterranean diet (MD) possess antiinflammatory properties and might offer protection for perceived stress and mood disorders (3). This systematic review investigated the effects of whole food interventions on stress, mood, and mental well-being.

The following databases were searched for studies published until the end of March 2024:

MEDLINE, CINAHL, Prospero, Web of Science, Cochrane Library (n = 6). Inclusion criteria were: (1) RCT; (2) mean participant age between 18 and 65 years; (3) measured one (or more) relevant outcomes e.g. stress, mood, or mental wellbeing; (4) whole food intervention. The Cochrane Risk of Bias v2 will be used to assess randomised controlled trials (RCT) (4).

The review identified 3,854 results in accordance with the PRISMA guidelines with fifteen meeting inclusion criteria. Backward citation searching yielded 8 studies. A total of twenty-three studies were included in this review. Seventeen applied whole food dietary intervention (WFDI) while six investigated supplementing the habitual i.e. adding nuts to diet (STH). Seventeen studies used WFDI: MD (n = 7), Nordic diet (n = 1), Ketogenic diet (n = 1), time-restricted eating (n = 1), a priori diets (n = 7). The remaining six STH studies supplemented with: nuts (n = 3), basil (n = 1), cacao (n = 1) and corn leaf (n = 1). Five studies reported positive changes in mood states i.e. vigor (p <.05). Two of these investigated the effects of a 10-day MD intervention compared to habitual diet, finding significant improvement in mood states (n = 4). Three studies measured mental well-being as an outcome with WFDI, MD (n = 1) and a priori diets (n = 2) reporting significance (p <.05) but demonstrating heterogenicity in measurement methods. Two studies were conducted with the outcome of stress with a WFDI, Mediterranean diet (n = 1) and a priori (n = 1). The findings reported to have a positive effect on reducing stress, when compared to baseline (p < .035). Four studies examined the effects of STH on mood states reporting positive significant change respectively: nut (n = 2), basil (n = 1), cacao (n = 1).

This systematic review is the first to examine the interaction of whole food intervention with stress, mood, and/or mental well-being. Our findings offer an insight to the interplay of different whole food interventions, whether entire diet or supplementation on the outlined outcomes in this review. The findings demonstrate heterogenicity of measurements which could be a factor in not establishing significance in some studies (n = 9). Other considerations of this review are the confounding variables that can influence stress, mood, and mental well-being such as physical activity, hydration, sleep quality.

Mealtime environments and food provision contexts in primary school influence students’ food behaviours(1) and are an opportunity for nutrition intervention(2). This study aims to explore primary school food provision contexts including eating environments and food provision models and policies. A quantitative cross-sectional online survey of Australian primary school teachers undertaken between August 2022-July 2023 collected data about: (1) designated eating times and locations for lunch and snacks; (2) teacher use of mealtimes for food and nutrition education; and(3) presence of food services and food-related policies. Descriptive statistics were generated using Stata 17.0 statistical software. Participants were 239 teachers recruited via social media advertising and education/nutrition networks. The majority of teachers reported their school provided allocated time for children to eat a morning snack (n = 201, 84%) and lunch (n = 234, 98%). Around three quarters of teachers reported an allocated eating time of 10 minutes or less for morning snack (n = 146, 73%) and 15 minutes or less for lunch (n = 174, 74%). Teachers stated lunch was most commonly eaten in the classroom with time to finish in the yard (n = 90, 38%) or in the yard as a group (n = 70, 30%). It was most common for morning snack to be eaten in the classroom (n = 119, 59%). Most teachers stated they had the opportunity to eat lunch with their students at least sometimes (n = 159, 67%). Of these teachers, 31% (n = 50) reported they used this time to teach students about food and nutrition, for example, in a pedagogical lunch. Of 109 teachers who did not use lunch time to teach students about food and nutrition, 43% (n = 69) stated they would be interested in doing this in the future. When asked about the availability of food services at their school, 62% (n = 147) of teachers reported their school had a canteen, 28% (n = 67) reported their school offered lunch orders via an external food outlet and 35% (n = 83) reported their school had a breakfast program. Only 34% of teachers reported their school had policies about the foods available from school food services. From these findings we conclude that a variety of mealtime and food provision contexts exist within Australian primary schools, and that there is opportunity to leverage eating occasions and food provision models and policies for nutrition intervention. This includes the opportunity to utilise mealtimes for delivering food and nutrition education, for example, through the concept of a pedagogical lunch.

Nutrition smartphone apps have become a popular and readily accessible approach to improving dietary behaviour. Hypertension is often associated with a poor diet, and its prevalence is increasing in Saudi Arabia(1). The Dietary Approaches to Stop Hypertension (DASH) eating plan has been shown to reduce blood pressure in people with hypertension(2). A previous study identified two high-quality, safe, and potentially effective smartphone apps for managing hypertension: NOOM and DASH To TEN(3). This study aimed to explore the potential of these two DASH diet self- management apps for controlling blood pressure in the Saudi Arabian context.

Fifteen patients were recruited at King Abdullah bin Abdulaziz University Hospital in Riyadh, Saudi Arabia. Ten patients had hypertension, and five had prehypertension (mean age = 45). Patients were given the two apps and asked to try each for one week. Focus groups (n=4) were held at the end of the trial to understand the patient perceptions of the apps. Discussions were recorded, and the transcriptions were analysed using a thematic framework analysis(4).

The following four themes emerged:

1. 1. Managing hypertension through diet was perceived as important. Most patients reported that

   adhering to the DASH diet was challenging due to a lack of motivation and willpower,

   inadequate support from household members, and high prices for healthy food.

2. 2. The potential and current reach of dietary apps emerged as a main theme, and many

   comments related to patients’ belief that dietary apps could increase their motivation and awareness about the DASH diet. Barriers to the use of apps were also identified including their difficulty of use, a preference for dietetic monitoring, and cost.

3. 3. Interactive app functionality was identified as a key theme, as evidenced by comments about a straightforward sign-up process, an extensive food database for dietary self-monitoring, feedback, goal setting, and reminders, considered essential for diet adherence.

4. 4. A preference for the NOOM app emerged. Patients perceived the NOOM app more suitable in the Saudi context. Noom was deemed to support DASH self-management because it supports weight reduction, which helps lower blood pressure. NOOM was perceived as highly interactive, offering motivational reminders, feedback, realistic dietary plans, and a comprehensive food database. Patients made several recommendations for app improvement; these included Arabic language support, automatic calculation of sodium and potassium consumption, and lower cost. Patients also expressed a desire for training in the use of the app.

This qualitative analysis suggests that the NOOM app could be suitable for use with hypertensive patients in Saudi Arabia. Further research is needed to determine the feasibility and efficacy of long- term use of the NOOM app with a Saudi Arabia population.

Steatotic liver disease, defined as >5% of hepatic fat content, is a major contributor to global morbidity and mortality, in particular due to its category metabolic associated steatotic liver disease (MASLD)(1). While its prevention focuses on promoting physical activity and maintaining a healthy weight and balanced diet, the associations between dietary fatty acids and liver fat remain unclear(2,3). The aim of this study was to examine the associations between dietary fatty acids and liver fat in the absence of excessive alcohol intake, independently of energy intake.

Analyses were conducted on 9,268 non-diabetic participants from the UK Biobank with no pre- existing liver chronic illness or cardiovascular disease at baseline, and without excessive alcohol consumption. Dietary intake of total fat, saturated fatty acids (SFAs), polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) was measured using the mean of ≥2 Oxford WebQ 24-hr dietary assessments, responded to between 2009 and 2012. Liver proton density fat fraction (LPDFF) was measured by magnetic resonance imaging between 2016 and 2020. Multivariable linear regression models were calculated to assess the associations between fatty acid intakes and LPDFF, adjusting for key demographic and lifestyle confounders. In addition, associations between LPDFF and 10 individual SFAs, 7 PUFAs, and 4 MUFAs were also examined. Sensitivity analyses were carried out including participants who responded ≥4 dietary assessments (N=2,828).

After fully adjusting for confounders, no significant associations between LPDFF (%) and MUFAs were found. Inverse associations with LPDFF were observed for PUFAs (−5.8% relative difference [95% confidence interval −0.6, −1.9]), per 5% increase in intake, while SFAs were positively associated with LPDFF (5.8% [3.3, 8.3]). Positive associations were observed per 1 SD increase in intake of individual fatty acids SFA stearic acid (4.20% [2.84, 5.57]) and palmitic acid (3.15% [1.78, 4.54]). Negative associations were observed for PUFAs alpha-linoleic acid (−2.32% [−3.47, −1.17]) and docosahexaenoic acid (−2.14% [−3.23, −1.0.3], and for MUFA erucic acid (−2.52% [−3.61, −1.43]). Sensitivity analyses presented similar results, and the associations between PUFAs and liver fat became slightly stronger (−10.73%, [−17.58, −3.32]).

This observational study suggests that SFAs and PUFAs are associated with liver fat in opposite directions, independently of energy intake. While total MUFAs did not present significant associations with LPDFF, erucic acid was inversely associated with liver fat, highlighting the value of studying individual fatty acids. These different associations provide valuable information for the design of dietary trials that compare interventions with different types of fatty acids. These further studies would allow a better understanding of the ideal dietary advice to prevent liver steatosis and its global health impact.

Tea produced from the tea plant (Camellia sinensis) is potentially beneficial for health: it contains theanine and caffeine which may improve short-term physiological outcomes such as accuracy of attention,(1,2) and polyphenols, specifically flavan-3-ols, which may improve long-term health outcomes such as cardiovascular diseases.(3,4) The aim of this systematic review and meta-analysis was to update the overall understanding of the effects of tea, or theanine (alone or in combination with caffeine), on cognition, mood, and/or sleep outcomes in healthy participants.

The Cochrane Library, Embase, and Medline were systematically searched, up to and including August 2023, for randomised controlled trials investigating the short-term effects of tea, theanine alone, or theanine plus caffeine interventions, on cognition, mood, and sleep outcomes in healthy participants. Where possible, meta-analysis was performed using standardised mean differences (SMD), or mean differences, with 95% confidence intervals (CI), in random effects models. SMDs and CIs were re-expressed (ReSMD) in the units of the most common measurement tool used by the studies in each meta-analysis.

Fifty RCTs were included in the review; data from fifteen RCTs were eligible for at least one meta-analysis. In the first hour (h1) and second hour (h2) after intake, differences were found between the effects of theanine plus caffeine, and placebo, that favoured the former, on cognitive outcomes including choice reaction time (h1; ReSMD: -24.71 ms; 95 % CI: -51.90 to 2.48), digit vigilance task accuracy (h2; ReSMD: 1.59 %; 95 % CI: 0.17 to 3.01), and attention switching task accuracy (h2; ReSMD: 1.10 %; 95 % CI: 0.43 to 1.77), and mood outcomes including overall mood (h2; ReSMD: 3.46 units on the caffeine research visual analogue scale; 95 % CI: -1.36 to 8.28) and alertness(h2; ReSMD: 2.94 units on the Bond-Lader visual analogue scale; 95 % CI: −0.87 to 6.75). Improvements favouring theanine, compared to placebo, were found for cognitive outcomes including rapid visual information processing accuracy (h2; ReSMD: 1.20 %; 95 % CI: 0.75 to 1.65) and reaction time (h2; ReSMD: -9.77 ms; 95 % CI: -16.98 to -2.55), and choice reaction time (h1; ReSMD: -18.01 ms; 95% CI: -31.27 to -4.83). No consistent evidence was found to indicate whether tea or theanine were beneficial for sleep.

This meta-analysis provides evidence that theanine plus caffeine, and theanine alone, possibly improve attention and mood, however, tea-inequivalent doses, small numbers of studies eligible for meta-analysis, and confidence intervals showing uncertainty surrounding the direction and magnitude of overall effect sizes, were common. More research of tea or tea-equivalent bioactive doses, in free-living participants, would be beneficial. PROSPERO registration no. CRD42022351601

Food-related infrastructure in primary schools can be used to deliver healthy and sustainable food education from a young age(1), though little is known about the presence and use of such infrastructure in primary schools. The aim of this study is to explore the use of physical infrastructure in healthy and sustainable food education in Australian primary schools. A quantitative cross-sectional online survey of primary school teachers undertaken between August 2022-July 2023 collected data about the presence and teaching-related use of food gardens, cooking facilities and food waste management systems in primary schools. Descriptive statistics were generated using Stata 17.0 statistical software. Participants were 239 teachers recruited via social media advertising and education/nutrition networks. The majority of teachers agreed that primary schools should have a food garden (n = 194, 81%), cooking facilities (n = 196, 82%) and a food waste system (n = 205, 86%) that can be used for teaching. Whilst three quarters of participants stated their school had a food garden (n = 181, 76%), just over half reported their school had cooking facilities (n = 130, 54%) or a food waste system (n = 131, 55%) that could be used for teaching purposes. More than 60% of participants reported they used such infrastructure within their teaching when it was available. Food waste systems were most commonly reported to be used more than once a week (n = 30, 33%) to teach students about food waste (n = 69, 77%), food sustainability (n = 65, 72%) and the environment (n = 63, 60%). Food gardens were most commonly reported to be used once a week (n = 33, 30%) to teach students about gardening skills (n = 97, 87%), the environment (n = 77, 69%), healthy eating (n = 67, 60%) and food sustainability (n = 67, 60%). Cooking facilities were most commonly reported to be used once or twice a term (n = 21, 23%) to teach students about food preparation and cooking (n = 71, 84%) and healthy eating (n = 62, 73%) and for tasting food (n = 55, 64%). From these findings we conclude that primary school teachers consider food gardens, cooking facilities and food waste systems to be important for delivering healthy and sustainable food education. Whilst food gardens appear to be common in Australian primary schools, there is variability in their use as an educational resource. Further variability exists regarding the presence and use of cooking facilities and food waste systems in primary school settings. There is future scope to (1) extend the presence of food-related infrastructure in primary schools; and (2) develop resources and training opportunities for teachers to support their use of such infrastructure in delivering healthy and sustainable food education for primary school students.

The global pandemic of paediatric overweight and obesity, along with undernutrition among children in low-income countries pose challenges for future health. Unhealthy dietary intake among children is of great concern(1). The aim of this study was to determine the association between intakes from healthy and unhealthy food groups and adiposity among 5- to 9-year-old South African children (n = 920). Conventional dietary intake assessment methods are burdensome; therefore, a short unquantified food frequency questionnaire was developed based on the WHO Global school-based student health survey, which focused on healthy and unhealthy food groups. The new questionnaire includes four healthy food groups (fruits, vegetables, milk, meats) and six unhealthy food groups (hot sugar-sweetened beverages (SSBs), cold SSBs, cookies, candies, salty snacks, fast foods) with five different responses of frequency of intake per week. The food groups reflect foods generally eaten by South African school children. The questionnaire was completed by the parents. Weight and height were measured and WHO BMI z-score (BAZ) was calculated(2). Descriptive statistics were reported using median and interquartile range. Frequency of intakes from food groups were compared across tertiles of BAZ using the Kruskal-Wallis test. The correlation between frequency of intakes from different food groups, and between the food groups and BAZ was calculated. The children reported similar daily intakes from the milk (35.3%), cold SSBs (33%) and hot SSBs groups (27%). Fruit (14%) and vegetables (9.6%) were consumed daily by a small percentage of children, while animal source protein foods (meat, fish, poultry, eggs) were consumed daily by 39% of children. The most frequent daily consumed snacks were salty snacks, e.g. crisps (13.2%), candy (11.1%) and cookies (5.3%), while fast foods were consumed once per week by the largest proportion of children (60.7%). Based on the WHO BMI z-scores, 15.2% of children were overweight, 4.4% were obese and 3.8% were underweight. Children in the highest two tertile groups of BAZ had a higher median weekly frequency of SSB intake (5, IQR 1,7), compared to those in the lowest BAZ tertile (3, IQR 1,7). No other differences were found between frequency of food group intake across BAZ tertiles. There was a weak positive correlation between BAZ and the frequency of SSB intake (r = 0.08, = 0.015), as well as between frequency of milk intake and frequency of SSB intake (r = 0.13, P<0.001), but a weak negative correlation between the frequency of vegetable intake and frequency of SSB intake (r = −0.08, P = 0.01). In conclusion, low fruit and vegetable intakes, combined with regular SSB intakes are evident in this group of children. The frequency of SSB intake was positively associated with adiposity, and SSB intake apparently replaced vegetable intake, but not milk intake among the children.

Approximately 40% of cancers in the UK are attributable to modifiable, lifestyle risk factors such as overweight and obesity and low dietary fibre intake(1). The WCRF and AICR published ten lifestyle- based Cancer Prevention Recommendations with the aim of reducing the risk of cancer and other non-communicable diseases(2). In the UK Biobank cohort, we have found reduced risk of cancer overall and of breast and colorectal cancers with greater adherence to these Cancer Prevention Recommendations (i.e., healthier lifestyles). The present study aimed to investigate whether the magnitude of these associations is modified by the presence of co-morbidities, such as diabetes and cardiovascular disease, at baseline.

We used data from 94,778 participants (53% female, mean age 56 years) from the UK Biobank prospective cohort study, recruited between 2006 and 2010 and free from cancer at baseline. Adherence to the 2018 WCRF/AICR Cancer Prevention Recommendations was calculated from dietary, physical activity, and body composition data using a standardised score(3). Multimorbidity (list of 43 chronic diseases) was self-reported at baseline and categorised into: 0, 1, 2, or 3+ chronic illnesses. Incident cancer cases were identified using population-based cancer registries available until July 2019 for England and Wales and October 2015 for Scotland. Participants were categorised into approximate score tertiles, and the lowest tertile (lowest adherence, 0-3.5 points) was used as the reference category. Cox proportional hazard models were used to investigate associations between total score and incidence of cancer, adjusting for confounders, and to test for an interaction between total score and multimorbidity.

55,191 (58%) participants had one chronic illness at baseline and 8,430 (9%) had ≥3. Mean total 2018 WCRF/AICR score was 3.8 (SD 1.0) points, and participants with the presence of chronic illnesses had a significantly lower total score (mean for ≥3 illnesses = 3.58 points vs 3.96 points for participants without chronic illness, p<0.001). During a median follow-up of 8 years, 3,303 individuals developed cancer. When investigating associations between score tertiles and the risk of cancer overall, there was a significant interaction between the total score and multimorbidity (HR for interaction: 1.59, p=0.002). There was also evidence for an interaction between total score and multimorbidity with breast cancer risk (HR for interaction: 1.23, p=0.030), but no evidence of an interaction between total score and multimorbidity for risk of colorectal cancer.

We found stronger associations between total adherence score and the risk of cancer in participants with ≥3 chronic illnesses. This suggests that the chemoprotective effects of greater adherence to the 2018 WCRF/AICR Cancer Prevention Recommendations may be particularly beneficial for individuals with multimorbidity.

University students often face high levels of stress and sleep disturbances due to their academic demands and lifestyle factors(1). Ashwagandha (Withania somnifera), an adaptogenic herb, has shown the potential to mitigate stress and improve cognitive function(2). However, limited research has examined its effects on these variables in university students. This study aimed to determine the effects of ashwagandha supplementation on sleep quality, mood, and cognitive function in university students.

A randomized, double-blind, placebo-controlled crossover study was used. Nine university students (5 males, 4 females; Age: 21±1 years; BMI: 25±2.5 kg/m2) were randomly assigned to receive 500 mg of standardized ashwagandha root extract capsules for 7 days or a placebo (encapsulated cornstarch) with a 7-day washout between treatments. Sleep was measured during the 7-day supplementation period using the Loughborough Daily Sleep Diary. Postsupplementation mood and cognitive function were measured by the Profile of Mood States (POMS) scale(3) and computerised Stroop, and Deary-Liewald simple and choice reaction tasks(4). Paired sample t-tests were used to determine differences between the ashwagandha and placebo conditions with calculated effect sizes (Cohen’s d).

Participants reported lower confusion indicator on the POMS following ashwagandha compared to the placebo (mean±SD: 4.8±2.0 vs 7.6±3.1 arbitrary units; P=0.03; d = −0.92). No other differences were found for any other mood indicators, sleep, or cognitive function parameters (P > 0.05).

These data suggest that ashwagandha may improve feelings of confusion in university students but further studies with larger sample sizes are needed to verify these findings and elucidate the underlying mechanisms.