The aim of this study was to evaluate the relative validity of food and nutrient intakes estimated by a brief-type diet history questionnaire for Japanese children and adolescents (BDHQ15y) designed to assess habitual dietary intake during the previous month. A total of 432 boys and 412 girls aged 6–17 years from thirty-two prefectures in Japan completed the BDHQ15y and subsequently provided 8-day weighed dietary records (DR) on two non-consecutive days over four seasons for comparison. Among the intakes of forty-four nutrients and thirty-one food groups adjusted for energy intake using the density model, the BDHQ15y showed percentage differences in median intake of less than 10 % compared with the DR for nineteen nutrients in both sexes, as well as for eleven and seven food groups in boys and girls, respectively, indicating good agreement for key nutrients and food groups, including protein, fat, carbohydrate, dietary fibre, grains, vegetables, dairy products and sugar-sweetened beverages (SSB). The median values (25th–75th percentiles) of Spearman’s correlation coefficients in boys and girls were 0·33 (0·28–0·38) and 0·28 (0·23–0·35) for nutrients, respectively, and 0·36 (0·29–0·42) and 0·29 (0·24–0·36) for food groups, respectively. Bland–Altman plots showed wide limits of agreement, with overestimation at higher intakes for most nutrients and food groups, except SSB. In conclusion, the BDHQ15y shows promise for large-scale dietary monitoring, particularly for estimating group-level intakes of key nutrients and food groups. However, its limited ability to rank individual intakes and the variability in individual-level assessments necessitate cautious interpretation and application.

Type 2 diabetes (T2D) incidence has been steadily increasing over the past few decades. Several studies have evaluated the effect of plant-based, vegetarian or vegan diets on the risk of T2D, although their potential benefits need to be confirmed and characterised. We performed a literature search up to 10 July 2025, using the terms/keywords related to plant-based index (PDI), vegetarian/vegan diets and T2D. We included observational non-experimental studies evaluating adherence to such diets in adult subjects assessing T2D risk. We specifically considered overall PDI and related healthy PDI (hPDI) and unhealthy PDI (uPDI), assessing intake of different food groups. We included 36 studies published between 1999 and 2025. We found an inverse association between adherence to vegetarian/plant-based dietary patterns and T2D risk. This association was stronger, though statistically imprecise, for the vegan diet (RR = 0·65, 95 % CI 0·42, 1·00) and for lacto-ovo-vegetarian diet (RR = 0·68, 0·57, 0·82). For studies using plant-based indices, the RR were 0·82 (0·69, 0·82), 0·76 (0·69, 0·82) and 1·13 (0·98, 1·30) for overall PDI, hPDI and uPDI, respectively. In the dose–response meta-analysis, overall PDI and hPDI showed an inverse and almost linear association with T2D risk. Conversely, adherence to uPDI directly correlated with T2D risk. Overall, adherence to vegan/vegetarian diets may reduce T2D risk, while an unhealthy plant-based diet appears to linearly increase disease risk, indicating caution in the consumption of such unhealthy foods even if of plant origin. The beneficial association between vegetarian and healthy plant-based diets may have major public health implications.

L-theanine, an amino acid found in tea, and caffeine, found in tea and coffee, are claimed to enhance attention. We conducted a double-blind, placebo-controlled, counterbalanced, two-way crossover trial to determine the acute effects of a high-dose L-theanine–caffeine combination on neurobehavioural (reaction time) and neurophysiological (P3b cognitive event-related potential (ERP)) measures of selective attention in acutely sleep-deprived healthy adults. Thirty-seven overnight sleep-deprived healthy adults (aged 22–30 years, twenty-one men) completed a computerised traffic-scene-related visual stimulus discrimination task before and 50 min after ingesting 200 mg L-theanine–160 mg caffeine combination or a placebo. The task involved selectively responding to imminent accident scenes (20 % probability) while ignoring randomly intermixed, more frequent safe scenes (80 % probability). A 32-channel electroencephalogram was recorded concurrently to derive ERP. The L-theanine–caffeine combination significantly improved the hit rate (P = 0·02) and target-distractor discriminability (P = 0·047), compared with the placebo. Although both L-theanine–caffeine combination (△ = 52·08 ms, P < 0·0001) and placebo (△ = 13·97 ms, P = 0·024) improved reaction time to accident scenes, the pre-post-dose reaction time improvement of the L-theanine–caffeine combination was significantly greater than that of placebo (△ = 38·1 ms, P = 0·003). Compared with the placebo, the L-theanine–caffeine combination significantly increased the amplitudes and reduced the latencies of P3b ERP component. Our findings suggest that L-theanine–caffeine combination improves the accuracy and speed of deploying selective attention to traffic scenarios in sleep-deprived individuals. This improvement is brought about by greater and faster neural resource allocation in the attentional networks of the brain.

The Scientific Advisory Committee on Nutrition (SACN) provides independent advice on nutrition and related health matters to UK government organisations. In keeping with its commitment to openness and transparency, SACN follows a set ‘Framework’ to ensure a prescribed and consistent approach is taken in all its evidence evaluations. Following an update of the SACN Framework in 2020, which addressed some straightforward issues, the SACN Framework subgroup was established in 2021 to consider more complex matters that were not addressed in the 2020 update. The SACN Framework subgroup considered four main topics for update: (1) the different types of evidence evaluations produced by SACN, (2) interpretation of statistical data, (3) tools for assessment of study quality and (4) tools to assess the certainty of a body of evidence for exposure–outcome relationships. The Framework subgroup agreed clear definitions and processes for the different types of evidence evaluations produced by SACN and agreed that interpretation of P values should be informed by consideration of study size, power and methodological quality. The subgroup recommended use of the AMSTAR 2 tool for quality assessment of evidence from systematic reviews and use of the Grading of recommendations, assessment, development and evaluation approach to assess the certainty of evidence. The updated Framework was published in January 2023. This was followed by publication of a further update in October 2024. As a ‘living’ document, the Framework will be subject to regular review by the Framework subgroup and continue to evolve in line with best practice.

To address limited data on whole grain (WG) consumption in the UK, we investigated trends and socio-demographic patterns of WG consumption from the National Diet and Nutrition Survey from 2008/2012 to 2016/2019 and examined the relationship between WG and dietary intakes. We analysed 15 655 individuals aged ≥ 1·5 years who completed a 4-day food diary. WG consumption was quantified by estimating the WG content of individual foods using publicly available ingredient information. Survey-weighted mean WG consumption over time and by population sub-group was calculated. Survey-weighted trend tests and Wald tests were used. Total WG intake in the general population did not change from 2008/2012 to 2016/2019. WG from high-fibre cereals and bread declined by 16·2 % (11·1–9·3 g/d) and 19·4 % (12·4–10 g/d), respectively, while other cereals (e.g. rice/pasta) increased by 72·5 % (4·0–6·9 g/d), but contributed considerably less than other categories. In the most recent data (2016–2019), older adults (65+ years) had the highest energy-adjusted WG consumption, followed by children 1·5–3 years. Individuals with lower incomes, adolescents and current smokers consumed the least WG. Whole grain intake was associated with generally higher quality diets, specifically consuming more fibre, potassium, Ca, Fe, Mg, fruits/vegetables, pulses/nuts and oily fish and consuming less free sugars, total fat, saturated fat, Na and red/processed meat (Ptrend < 0·001 for all). Despite some dietary improvements in the UK, WG intake appears unchanged from 2008/2012 to 2016/2019.

Diet in the first years of life is a key determinant of lifelong disease risk and is highly affected by socio-economic status (SES). However, the specific relation between SES and food consumption in toddlers and preschoolers is poorly understood. This study assesses SES-related differences in food consumption in 1- to 5-year-olds in Germany using weighed food records (3 + 1 d) of a subsample of 887 children from the cross-sectional Children’s Nutrition Survey to Record Food Consumption (KiESEL) undertaken between 2014 and 2017. Children were categorised as having a low, medium or high SES depending on parental income, education and occupation. A two-step generalised linear model corrected for age and sex was applied to assess differences in food consumption, using bootstrapping to address unequal group sizes. Differences between SES groups were found for unfavourable foods (and the subgroups sugar-sweetened beverages and confectionary/desserts), fruit, bread/cereals and fats/oils (PBoot < 0·05). Mean daily consumption in the low-SES group as compared with the high-SES group was 84 g lower for total fruit, 22 g lower for bread/cereals and 3 g lower for fats/oils, while being 123 g higher for sugar-sweetened beverages and 158 g higher for unfavourable foods in total (based on bootstrap 95 % CI). In conclusion, this study suggests a social gradient in the diet of German toddlers and preschoolers, with lower SES linked to lower diet quality. To prevent adverse health trajectories, public health measures to improve early life nutrition should address all children, prioritising those of lower SES.

This study examined whether supplementation with collagen peptides (CP) affects appetite and post-exercise energy intake in healthy active females. In this randomised, double-blind cross-over study, fifteen healthy females (23 (sd 3) years) consumed 15 g/d of CP or a taste matched non-energy control (CON) for 7 d. On day 7, participants cycled for 45 min at ∼55 % Wmax, before consuming the final supplement. Sixty-min post supplementation an ad libitum meal was provided, and energy intake recorded. Subjective appetite sensations were measured daily for 6 d (pre- and 30 min post-supplement) and pre (0 min) to 280 min post-exercise on day 7. Blood glucose and hormone concentrations (total ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), cholecystokinin (CCK), dipeptidyl peptidase-4 (sDPP-4), leptin, and insulin) were measured fasted at baseline (day 0), then pre-breakfast (0 min), post-exercise (100 min), post-supplement (115, 130, 145, 160 min) and post-meal (220, 280 min) on day 7. Ad libitum energy intake was ∼10 % (∼41 kcal) lower in the CP trial (P = 0·037). There was no difference in gastrointestinal symptoms or subjective appetite sensations throughout the trial (P ≥ 0·412). Total plasma GLP-1 (AUC, CON: 6369 (sd 2330); CP: 9064 (sd 3021) pmol/l; P < 0·001) and insulin (+80 % at peak) were higher after CP (P < 0·001). Plasma ghrelin and leptin were lower in CP (condition effect; P ≤ 0·032). PYY, CCK and glucose were not different between CP and placebo (P ≥ 0·100). CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced ad libitum energy intake at a subsequent meal in physically active females.

This study explored whether lifestyle therapy that promoted adherence to a Mediterranean-style diet as a treatment for depression led to environmental co-benefits. Participants (n 75 complete case) were Australian adults in the Curbing Anxiety and Depression using Lifestyle Medicine non-inferiority, randomised controlled trial, which showed that lifestyle therapy was non-inferior to psychotherapy in reducing depressive symptoms, when delivered in group format via video conferencing over an 8-week treatment period. In this secondary analysis, we hypothesised that the lifestyle arm would be superior to the psychotherapy arm in reducing the environmental impact of self-reported diet over time. Dietary intake derived from FFQ at baseline and 8 weeks was transformed into environmental impact scores by calculating global warming potential (GWP)*. GWP* was calculated for total dietary intake and distinct food groups (Australian Dietary Guidelines and NOVA classifications). Within-arm changes in GWP* over time were calculated using the median difference. Neither arm showed significant changes. Between-arm differences in percentage change in GWP* scores over time were analysed using generalised estimating equations models. No between-arm difference for total GWP* score was found (β = 11·06 (–7·04, 29·15)). When examining distinct food groups, results were mixed. These novel findings contribute to the sparse evidence base that has measured the environmental impact of diets in a clinical trial context. Whilst lifestyle therapy that reduced depressive symptoms did not have clear environmental benefits relative to psychotherapy, nutritional counselling that focuses on the environmental impact of food choices may drive more pronounced planetary co-benefits.

Using a behavioural intervention to target nutrition during pregnancy may be key in meeting recommendations for healthy eating. The aim was to assess the use of a short-term dietary intake measurement tool (3-day food intake record) to infer long-term habitual dietary intake during pregnancy (using a short-form FFQ). A convenience sample (n 90) between 12- and 18-weeks’ gestation was recruited from a larger randomised controlled trial for cross-sectional analysis. Participants completed a forty-four-item FFQ and 3-day food intake record. Using the participant food intake record, the investigator blindly completed a second frequency questionnaire. The frequency questionnaires were scored using dietary quality scores (DQS) and compared. Aggregate data were evaluated using a Wilcoxon signed rank test, and individual-level data were evaluated using a Bland–Altman plot. No significant difference was observed in the scores (Z = –1·88, P = 0·06), with small effect size (r= 0·19). The Bland–Altman plot showed that comparing the DQS derived from the two different dietary assessments underestimated scores by a mean difference of 0·4 points (95 % limits of agreement: −3·50 to 4·26). The data points were evenly spread suggesting no systematic variation for over- or underestimation of scores. Minimal difference was observed between the functionality of the two assessment instruments. However, the food intake record can be completed by pregnant individuals to estimate short-term nutrient intake and then scored by the investigator to estimate long-term dietary quality. Combining these two instruments may best capture the most accurate representation of dietary habits over time.

A local food-based approach, including school lunch with multiple-micronutrient fortified biscuits (MMB) as supplementary snacks, may enhance dietary adequacy, although current evidence remains limited. This study assessed nutrient inadequacies and developed food-based dietary recommendations (FBR) incorporating school lunch from the Ghana School Feeding Programme (GSFP) and MMB. Data from 292 girls aged 10–17 years, enrolled in the Ten2Twenty-Ghana study was analysed. Dietary intake was assessed via a quantitative 24-h dietary recall. Usual intakes were estimated using the National Cancer Institute method. Linear programming with Optifood was used to develop FBRs based on commonly consumed foods (≥5% of participants) and their median serving sizes, intake frequency, nutrient content, and cost per 100 g. Constraints included estimated energy needs and harmonised average nutrient requirements. The mean usual energy intake was 2351 (sd 66) kcal/d. Ca (99·8 %), vitamin B12 (99·8 %), riboflavin (96·2 %), vitamin A (91·5 %), vitamin C (87·6 %), Fe (73·7 %), folate (49·3 %) and Zn (8·5 %) inadequacies were prevalent. Optimised diets achieved adequacy for protein and most micronutrients, except Ca and vitamin B12, besides vitamin A for 15–17-year-old girls. School lunch from the GSFP did not enhance micronutrient levels when added to the daily diet. Adding MMB to the daily diet ensured adequacy for vitamin C, riboflavin and Fe, although marginal for Fe. Ca and vitamin A improved substantially with MMB for girls aged 15–17 but remained below the harmonised average requirements. Integrating regular school lunch with specialised fortified foods may be a cost-effective strategy to enhance dietary adequacy for adolescent girls in rural areas.

There has been substantial research undertaken on the role of a health-promoting diet in depression. Yet, the evidence of the relationship between the Nordic diet and the risk of depression is scarce. This cross-sectional study aimed to assess whether a healthy Nordic diet is associated with depressive symptoms. In total, 2603 men aged 42–60 years from the Kuopio Ischaemic Heart Disease Risk Factor Study were included. Diet quality was evaluated with a healthy Nordic diet score derived from the 4-day food diaries and depressive symptoms with the self-reported Human Population Laboratory (HPL) depression scale. Quade ANCOVA was used to examine the mean values of HPL scores in quartiles of a healthy Nordic diet score. Participants’ mean age was 53 years and BMI 26·8 kg/m2; 31·7 % were current smokers, and 86·9 % were married or living as a couple. The mean healthy Nordic diet score was 12·8 (sd 4·0, range 2–25), and the mean HPL depression score was 1·9 (sd 2·1, range 0–13). The findings suggested that lower adherence to a healthy Nordic diet was associated with higher HPL depression scores after adjusting for age, examination year, daily energy intake, leisure-time physical activity, adulthood socio-economic status, smoking and marital status (extreme quartile difference: 0·33 points, 95 % CI 0·10, 0·56, P for trend across the quartiles = 0·003). The results support the hypothesis that a lower-quality diet increases the odds of having depressive symptoms. However, prospective studies are needed to confirm the association.

Diet quality has been linked to socio-economic status. However, evidence within rural and regional populations is lacking. This cross-sectional study examined the relationship between diet quality and socio-economic position in adults living in rural and regional areas of Australia. The Australian Recommended Food Score (ARFS; range 0–73) measured diet quality (total and subscale scores). Area-level socio-economic position was determined by postcode-linked socio-economic index for areas (SEIFA), Index of Relative Social Advantage and Disadvantage scores, stratified into quintiles. The mean total ARFS (34·7; sd = 9·1; n 836) was classified as ‘getting there’. Findings showed significantly lower mean total ARFS between SEIFA quintile 1 (1 = lowest; mean total ARFS = 30·4; sd = 10·2; categorised as ‘needs work’) compared with all other SEIFA quintiles (F (44 831) = 8·44, P ≤ 0·001). Linear regression, adjusting for age, sex, income, education, employment status and household composition demonstrated significantly lower overall diet quality for SEIFA quintile 1 compared with SEIFA quintile 3 (B = –3·9; 95 % CI (–6·2, −1·5); P < 0·001) and lower subscale scores for vegetables (B = –1·6; 95 % CI (–2·7, −0·6); P = 0·003), fruit (B = –0·9; 95 % CI (–1·6, −0·1); P = 0·018) and grains (B = –0·6; 95 % CI (–1·3, −0·0); P = 0·050). After adjusting for individual confounders of diet quality, results indicate that lower area-level socio-economic position remained associated with poorer diet quality in this sample of rural and regional Australian adults. This suggests that broader social and environmental factors unique to these areas may impact diet quality and amplify individual barriers to achieving a healthy diet.

The RDA for dietary protein is likely insufficient for individuals with cystic fibrosis (CF). This study sought to characterise protein intake and diet quality in adults with cystic fibrosis (awCF), before and after elexacaftor/tezacaftor/ivacaftor (ETI) therapy, compared with healthy controls. Dietary intake was assessed by diet diary in awCF at baseline (BL, n 40) and at follow-up > 3 months post ETI therapy (follow-up (FUP), n 40) and in age-matched healthy controls (CON, n 80) free from known disease at a single time point. Protein intake dose and daily distribution, protein quality, protein source and overall diet quality were calculated for each participant. Both CON (1·39 (sd 0·47) g·kg–1·day–1) and CF (BL: 1·44 (sd 0·52) g·kg–1·day–1, FUP: 1·12 (sd 0·32) g·kg–1·day–1) had a higher mean daily protein intake than the protein RDA of 0·75g·kg–1·day–1. There was a significant reduction in daily protein intake in the CF group at FUP (P = 0·0003, d = 0·73), with levels below the alternative suggested dietary intake of ≥ 1·2 g·kg–1·day–1. There were no sex differences or noticeable effects on protein quality or source following the commencement of ETI therapy when compared with CON (all P > 0·05), although overall diet quality decreased between time points (P = 0·027, d = 0·57). The observed reduction in daily protein intake in the present cohort emphasises the importance of ensuring appropriate dietary protein intake to promote healthy ageing in adults with CF. More research is needed to evidence base dietary protein requirements in this at-risk population.

Sessile serrated lesions (SSL) are recognised precursors to colorectal cancer. Little is known about risk factors for SSL due to their relatively recent clinical recognition as a cancer precursor and routine documentation of cases. Lifestyle and diet-related information were collected using validated questionnaires in a colonoscopy-based case–control study in Australia (257 SSL cases, 239 conventional adenoma (CA) cases, 180 polyp-free controls). A posteriori dietary patterns were derived from self-reported dietary intake in the past 12 months using principal component analysis. Multivariable-adjusted OR and 95 % CI were used to examine associations between lifestyle factors and dietary patterns on risk of SSL and CA v. polyp-free controls and SSL v. CA using logistic regression modelling. Use of anti-inflammatory medications was associated with reduced SSL risk (OR = 0·61; 95 % CI 0·38, 1·00), while current smoking was associated with increased SSL risk (OR = 1·96; 95 % CI 1·09, 3·53). Unlike CA, SSL risk was not increased by hormone replacement therapy use and current alcohol consumption but was increased by taller height. Higher adherence to a dietary pattern featuring processed meats, ready-made convenience foods and high-energy drinks was associated with increased SSL risk (OR = 2·13; 95 % CI 1·13, 4·00; Ptrend = 0·03) and CA (OR = 2·60; 95 % CI 1·32, 5·09; Ptrend = 0·005). Compared with CA, a dietary pattern featuring wholegrains, low-fat dairy products, nuts, seeds and oily fish was associated with reduced SSL risk (OR = 0·60; 95 % CI 0·36, 0·98; Ptrend = 0·04). This study supports a healthy diet as primary prevention for both SSL and CA and reinforces smoking as a risk factor for SSL.

Vitamin A deficiency (VAD) poses significant health risks and is prevalent in children and adolescents in India. This study aimed to determine the effect of seasonal variation and availability of vitamin A-rich (VA-rich) foods on serum retinol in adolescents. Data on serum retinol levels from adolescents (n 2297, mean age 14 years) from the Comprehensive National Nutrition Survey (2016–2018) in India were analysed, with VAD defined as serum retinol < 0·7 µmol/L. Five states were selected based on a comparable under-five mortality rate and the seasonal spread of the data collection period. Dietary data from adolescents and children ≤ 4 years old were used to assess VA-rich food consumption. A linear mixed model framework was employed to analyse the relationship between serum retinol, month of the year and VA-rich food consumption, with a priori ranking to control for multiple hypothesis testing. Consumption of VA-rich foods, particularly fruits and vegetables/roots and tubers, showed seasonal patterns, with higher consumption during summer and monsoon months. Significant associations were found between serum retinol concentrations and age, month of sampling, consumption of VA-rich foods and fish. VAD prevalence was lowest in August, coinciding with higher consumption of VA-rich fruits and foods. Findings highlight the importance of considering seasonality in assessing VAD prevalence and careful interpretation of survey findings. Intentional design, analysis and reporting of surveys to capture seasonal variation is crucial for accurate assessment and interpretation of VAD prevalence, including during monitoring and evaluation of programmes, and to ensure that public health strategies are appropriately informed.