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.

Peer support interventions for dietary change may offer cost-effective alternatives to interventions led by health professionals. This process evaluation of a trial to encourage the adoption and maintenance of a Mediterranean diet in a Northern European population at high CVD risk (TEAM-MED) aimed to investigate the feasibility of implementing a group-based peer support intervention for dietary change, positive elements of the intervention and aspects that could be improved. Data on training and support for the peer supporters; intervention fidelity and acceptability; acceptability of data collection processes for the trial and reasons for withdrawal from the trial were considered. Data were collected from observations, questionnaires and interviews, with both peer supporters and trial participants. Peer supporters were recruited and trained to result in successful implementation of the intervention; all intended sessions were run, with the majority of elements included. Peer supporters were complimentary of the training, and positive comments from participants centred around the peer supporters, the intervention materials and the supportive nature of the group sessions. Attendance at the group sessions, however, waned over the intervention, with suggested effects on intervention engagement, enthusiasm and group cohesion. Reduced attendance was reportedly a result of meeting (in)frequency and organisational concerns, but increased social activities and group-based activities may also increase engagement, group cohesion and attendance. The peer support intervention was successfully implemented and tested, but improvements can be suggested and may enhance the successful nature of these types of interventions. Some consideration of personal preferences may also improve outcomes.

Adhering to a Mediterranean diet (MD) is associated with reduced CVD risk. This study aimed to explore methods of increasing MD adoption in a non-Mediterranean population at high risk of CVD, including assessing the feasibility of a developed peer support intervention. The Trial to Encourage Adoption and Maintenance of a MEditerranean Diet was a 12-month pilot parallel group RCT involving individuals aged ≥ 40 year, with low MD adherence, who were overweight, and had an estimated CVD risk ≥ 20 % over ten years. It explored three interventions, a peer support group, a dietician-led support group and a minimal support group to encourage dietary behaviour change and monitored variability in Mediterranean Diet Score (MDS) over time and between the intervention groups, alongside measurement of markers of nutritional status and cardiovascular risk. 118 individuals were assessed for eligibility, and 75 (64 %) were eligible. After 12 months, there was a retention rate of 69 % (peer support group 59 %; DSG 88 %; MSG 63 %). For all participants, increases in MDS were observed over 12 months (P < 0·001), both in original MDS data and when imputed data were used. Improvements in BMI, HbA1c levels, systolic and diastolic blood pressure in the population as a whole. This pilot study has demonstrated that a non-Mediterranean adult population at high CVD risk can make dietary behaviour change over a 12-month period towards an MD. The study also highlights the feasibility of a peer support intervention to encourage MD behaviour change amongst this population group and will inform a definitive trial.

This work investigated the effects of repeated sweet taste exposure at breakfast on perceptions and intakes of other sweet foods, while also examining the effects due to duration of exposure (1/3 weeks), test context (breakfast/lunch) and associations between taste perceptions and intakes. Using a randomised controlled parallel-group design, participants (n 54, 18 male, mean age: 23·9 (sd 5·8) years, mean BMI: 23·6 (sd 3·5) kg/m2) were randomised to consume either a sweet breakfast (cereal with sucralose) (n 27) or an equienergetic non-sweet breakfast (plain cereal) (n 27) for 3 weeks. On days 0 (baseline), 7 and 21, pleasantness, desire to eat and sweetness were rated for other sweet and non-sweet foods and sweet food consumption was assessed in an ad libitum meal at breakfast and lunch. Using intention-to-treat analyses, no statistically significant effects of exposure were found at breakfast (largest F2,104 = 1·84, P = 0·17, ηp2 = 0·03) or lunch (largest F1,52 = 1·22, P = 0·27, ηp2 = 0·02), and using Bayesian analyses, the evidence for an absence of effect in all rating measures was strong to very strong (smallest BF01 = 297·97 (BF01error = 2·68 %)). Associations between ratings of pleasantness, desire to eat and intake were found (smallest r = 0·137, P < 0·01). Effects over time regardless of exposure were also found: sugars and percentage energy consumed from sweet foods increased throughout the study (smallest (F2,104 = 4·54, P = 0·01, ηp2 = 0·08). These findings demonstrate no effects of sweet taste exposure at breakfast for 1 or 3 weeks on pleasantness, desire for, sweetness or intakes of other sweet foods in either the same (breakfast) or in a different (lunch) meal context.

Eggs tend to be eaten irregularly, e.g. they are often eaten as a standby for unplanned meals, and have been reported to be eaten as a treat or on special occasions. This intrapersonal variation may impact the accuracy of measuring the habitual intake of eggs. Food frequency questionnaires (FFQs) are often validated for nutrients but not foods, and may not be suitable for measuring the consumption of individual foods. The validity of measuring the consumption of specific foods can be particularly affected for foods with a greater within-person variation. Moreover, FFQs rarely include a detailed intake measure of eggs, and often do not include eggs in mixed dishes. With epidemiological studies focussing on individual foods to assess associations between foods and diseases, it is important to consider the accuracy of dietary assessment methods in measuring intake of individual foods.

In the current study we compare egg intake data from a validated FFQ and egg intake data from an FFQ specifically designed to measure egg intake. Both questionnaires were completed by a sample of 100 community-dwelling healthy older adults, which included 54 females and 46 males, with mean age 70 (SD = 7) years. Both FFQs had a similar layout, but the validated FFQ section on egg intake consisted of three questions on egg intake, while the egg FFQ included 18 preparations of eggs, including mixed dishes.

Mean monthly egg consumption for the validated FFQ was 16 (SD = 13) eggs, while the egg FFQ showed an egg intake of 22 (SD = 16) eggs per month, suggesting under- or over-reporting on one or both measures. Although the mean values are noticeably different, validated FFQ egg intake correlates strongly with egg FFQ intake (r = .773, p < .001).

National Diet and Nutrition Survey data indicates that British older adults (65 years + ) consume 33 g of eggs/egg dishes per day, the equivalent of 16–17 eggs per month. This means that the validated FFQ egg intake of 16 eggs per month is more similar to the NDNS data. However, FFQs generally tend to overestimate food intake compared to diet records and the validated FFQ is validated for the total nutrient intake, not for individual foods. With only three questions and without including mixed dishes, the validated FFQ may under-estimate intake of eggs, while the egg FFQ may be more comprehensive. More research is needed to explore the most appropriate methods for measuring intakes of foods that are irregularly consumed, such as eggs.

A randomized controlled intervention study was undertaken to increase egg and protein intake in community-dwelling adults over 55 years old. During a 12 week intervention, recipes for protein-rich egg-based meals and single-use herbs/spice packets were provided to 53 individuals in the intervention group to promote the addition of flavour and variety to the diet. Egg intakes increased by 20%, and this increase was sustained up to 12 weeks after the end of the intervention. Exploratory analyses however revealed some individual differences within the intervention group, where some participants increased their egg intake and others did not.

We compared the participants who increased their egg intake to those who did not on several demographic characteristics and baseline outcomes, and explored the qualitative feedback related to recipe use collected after the intervention.

Results show that the participants who increased their egg intake during the intervention (n = 27) had a significantly higher BMI (U = 402, p = .035), a lower health-related quality of life (U = 198, p = .047), and take external reports and recommendations about eggs and health from media and health professionals more seriously (U = 399, p = .038) than those who did not increase egg intake. Those who increased their egg intake during the 12 week follow up period (n = 19) reported a lower availability of eggs during their upbringing (U = 371, p = .041), with no other differences between the groups.

Feedback from the whole group showed that reasons for choosing to use or not use the recipes were based on preferences, culinary skills, time/effort to prepare the meal, having ingredients already in the cupboard, the importance of variety, habits and familiarity, and the portion sizes, which were generally considered too large. The recipes used most often included ingredients that are more traditionally combined with eggs in the English diet (e.g. cheese/ham), while the recipes used least often were more unfamiliar (e.g. Turkish eggs with yoghurt).

Our study used recipes that specifically focus on eggs, but our findings suggest that recipe based interventions in this age group may be particularly beneficial for those with a higher BMI, those who may feel their health could be improved, those who are more likely to respect external advice, and those who have less early experience with the included foods. Greater future benefit may also be obtained from recipes that are for smaller dishes, using familiar ingredients, and that cater to a range of culinary skills and preferences.

Low intakes of fruit and vegetables have previously been reported in the older population of Great Britain, particularly among certain socio-demographic groups. Levels and patterns of consumption in the older population of Northern Ireland, however, remain unknown. A representative sample of 1000 members of the older population of Northern Ireland were contacted by telephone to assess average intake of all fruits and vegetables and various demographic details. Data from 426 individuals (representative of the whole population) reported a mean consumption of 4·0 (sd 1·3) and 4·1 (sd 1·3) portions of fruit and vegetables per weekday and per weekend day respectively. Regression analyses revealed greater consumption on weekdays by females (B 0·53; P < 0·01), younger individuals (B − 0·02; P = 0·01) and those living in less deprived areas (B − 0·01; P = 0·04), and greater consumption at weekends by females (B 0·54; P < 0·01) and younger individuals (B − 0·03; P = 0·01). The amount of fruit and vegetables consumed is slightly higher than that reported in older populations in Great Britain, possibly as a result of differences in farming practices and rural activities, although levels of consumption remain below current recommendations for health. Patterns of consumption are similar across the UK, and suggest that strategies to increase fruit and vegetable consumption should target males, older individuals and those living in more deprived areas.

We recently reported a null outcome from a study of n-3 long-chain PUFA supplementation in depressed mood(1).

Low dietary intakes of the n-3 long-chain PUFA (LCPUFA) EPA and DHA are thought to be associated with increased risk for a variety of adverse outcomes, including some psychiatric disorders. Evidence from observational and intervention studies for a role of n-3 LCPUFA in depression is mixed, with some support for a benefit of EPA and/or DHA in major depressive illness. The present study was a double-blind randomised controlled trial that evaluated the effects of EPA+DHA supplementation (1·5 g/d) on mood and cognitive function in mild to moderately depressed individuals. Of 218 participants who entered the trial, 190 completed the planned 12 weeks intervention. Compliance, confirmed by plasma fatty acid concentrations, was good, but there was no evidence of a difference between supplemented and placebo groups in the primary outcome – namely, the depression subscale of the Depression Anxiety and Stress Scales at 12 weeks. Mean depression score was 8·4 for the EPA+DHA group and 9·6 for the placebo group, with an adjusted difference of − 1·0 (95 % CI − 2·8, 0·8; P = 0·27). Other measures of mood, mental health and cognitive function, including Beck Depression Inventory score and attentional bias toward threat words, were similarly little affected by the intervention. In conclusion, substantially increasing EPA+DHA intake for 3 months was found not to have beneficial or harmful effects on mood in mild to moderate depression. Adding the present result to a meta-analysis of previous relevant randomised controlled trial results confirmed an overall negligible benefit of n-3 LCPUFA supplementation for depressed mood.