British Journal of Nutrition最新文献

Ultra-processed foods (UPFs), defined using frameworks such as NOVA, are increasingly linked to adverse health outcomes, driving interest in ways to identify and monitor their consumption. Artificial intelligence (AI) offers potential, yet it's application in classifying UPFs remains underexamined. To address this gap, we conducted a scoping review mapping how AI has been used, focusing on techniques, input data, classification frameworks, accuracy, and application. Studies were eligible if peer-reviewed, published in English (2015-2025), and they applied AI approaches to assess or classify UPFs using recognised or study-specific frameworks. A systematic search in May 2025 across PubMed, Scopus, Medline, and CINAHL identified 954 unique records with eight ultimately meeting the inclusion criteria; one additional study was added in October following an updated search after peer review. Records were independently screened and extracted by two reviewers. Extracted data covered AI methods, input types, frameworks, outputs, validation, and context. Studies used diverse techniques, including random forest classifiers, large language models, and rule-based systems, applied across various contexts. Four studies explored practical settings: two assessed consumption or purchasing behaviours, and two developed substitution tools for healthier options. All relied on NOVA or modified versions to categorise processing. Several studies reported predictive accuracy, with F1 scores from 0.86 to 0.98, while another showed alignment between clusters and NOVA categories. Findings highlight the potential of AI tools to improve dietary monitoring and the need for further development of real-time methods and validation to support public health.

There is substantial international variation in recommended vitamin C intake levels. In the United States, the recommendation is 90 mg/day for men and 75 mg/day for women, while in the United Kingdom (UK), the current recommendation - established in 1991 - is only 40 mg/day for adults. This UK level was based on the 1953 Sheffield study, which found that 10 mg/day prevents scurvy, with 40 mg/day chosen as the recommended level for yielding somewhat higher plasma levels. In this commentary, we argue that the UK recommendation overlooked key evidence available at the time. Specifically, at least six controlled trials published before 1991 reported benefits from vitamin C supplementation in participants whose baseline vitamin C intake was already 40 mg/day or higher. One randomized controlled trial, published in 1993, found benefits from vitamin C supplementation even at a baseline intake of about 500 mg/day; however, this trial involved ultramarathon runners, and the findings should not be broadly generalised. Nonetheless, such results challenge the assumption that 40 mg/day is universally adequate to maintain full health. We also highlight that the UK recommendations were narrowly focused on preventing dermatological symptoms of scurvy, despite strong evidence - even at the time - that vitamin C deficiency can also cause cardiac dysfunction and greater morbidity due to respiratory infections. We conclude that the current UK vitamin C recommendation should be re-evaluated in light of controlled trial evidence and broader clinical outcomes.

Obesity and depression are highly prevalent diseases that are strongly correlated. At the same time, there is a growing gap in care, and treatment options should be improved and extended. Positive effects of a Mediterranean diet on mental health have already been shown in various studies. In addition to the physiological effects of nutrients, the way food is eaten, such as mindful eating, seems to play a role. The present study investigates the effect of a Mediterranean diet and mindful eating on depression severity in people with clinically diagnosed major depressive disorder and obesity. Participants will be randomised to one of the four intervention groups (Mediterranean diet, mindful eating, their combination and a befriending control group). The factorial design allows investigating individual effects as well as potential synergistic effects of the interventions. The study consists of a 12-week intervention period, where five individual appointments will take place, followed by a 12-week follow-up. The primary outcome is depression severity. Secondary outcomes are remission of depression, assessor-rated depression severity, quality of life, self-efficacy, BMI, waist:hip ratio and body composition; adherence to the Mediterranean diet and mindful eating will also be assessed. Alongside mediator and moderator analysis, a microbiome analysis, a qualitative evaluation and an economic analysis will be conducted. The study investigates an important health issue in a vulnerable target group. It allows to draw valuable conclusions regarding the effectiveness of different interventions and therefore contributes to improving available care options for people suffering from depression and obesity.

Previous studies have shown that low-fat diet (LFD) is associated with various health benefits, and that lipid and fatty acid metabolism is linked to telomere shortening. However, no epidemiological studies have examined the association between LFD and telomere length (TL). Dietary information was collected using 24-h recalls among 6981 adults from a nationwide cross-sectional study. Diet quality was assessed using overall LFD, healthful LFD (hLFD) and unhealthful LFD (uLFD). TL was measured using quantitative PCR. Linear regression was employed to evaluate the association between LFD and log-transformed TL, and ordinal logistic regression was performed to assess the association of LFD with ordinal quintiles of TL in descending order. In both fully adjusted linear and ordinal regression models, higher overall LFD (Tertile 3 v. Tertile 1: percentage change = 2·48 %, 95 % CI: 0·60 %, 4·40 %, P_trend = 0·003; OR = 0·79, 95 % CI: 0·68, 0·93; P_trend = 0·001) and hLFD (Tertile 3 v. Tertile 1: percentage change = 2·71 %, 95 % CI: 0·87 %, 4·58 %; P_trend = 0·002; OR = 0·84, 95 % CI: 0·72, 0·97; P_trend = 0·003) scores were significantly associated with longer TL. The positive association between hLFD and TL was observed in other racial/ethnic groups, but not in non-Hispanic whites (P_interaction < 0·005). There was no significant association between uLFD and TL in all the models. Our results suggest that LFD rich in high-quality carbohydrates, unsaturated fat and plant protein is associated with longer TL and underscore the need to consider the quality and dietary sources of the macronutrients.

The evaluation of usual food intake is of central importance in nutritional epidemiology studies. Some authors propose the usual dietary recall (UDR) as a viable method for assessing usual food intake; however, its characteristics remain poorly understood. The objective of this study is to review the literature on the application and performance characteristics of the UDR as a dietary assessment method. Electronic search strategies were conducted using the Excerpta Medica Database, Publisher Medline, Cochrane Central Register of Controlled Trials, Latin American and Caribbean Health Sciences Literature, Coordination for the Improvement of Higher Education Personnel (CAPES) Periodicals Portal, and Google Scholar. Studies published in Portuguese, English, and Spanish were included, with no restrictions on publication date. Eligible studies included those utilising the UDR in experimental or observational designs, as well as literature reviews. A total of 116 studies were included in the review. The most common application method (n 34; 29·3 %) involved reporting foods typically consumed over a 24-h period. However, most studies (n 66; 56·9 %) did not specify the method for applying the UDR. Key limitations identified included under or overestimation (n 9; 7·8 %), memory bias (n 7; 6·0 %) and the lack of instrument validation (n 5; 4·3 %). Findings show that the UDR lacks a standardised application method, and its validity remains unconfirmed. Future research should establish a standardised protocol and assess its psychometric properties to reduce errors and biases, ensuring accurate dietary assessments in nutritional epidemiology.

There is a gap in the understanding of meal patterns offered to students targeted by the National School Feeding Programme (PNAE). This study aimed to identify and analyse the menu patterns planned in schools participating in the PNAE. This observational cross-sectional study was carried out from a database consisting of 557 weekly menus from primary schools across Brazilian municipalities. We used factor analysis (FA) with principal components analysis (PCA) to identify menu patterns. Nutritional quality assessment of the menus was based on the Revised School Feeding Menu Quality Index (IQCAE-R). Differences in nutritional quality and associations with sociodemographic factors were analysed using the Kruskal-Wallis test, followed by Wilcoxon post hoc testing with Bonferroni correction. Two menu patterns were identified: (1) 'Traditional', predominantly composed of cereals and pasta, roots and tubers, legumes, vegetables, and meats and eggs; and (2) 'Snack', with a higher occurrence of bread, cakes, and biscuits, milk and dairy products, chocolate powder, and coffee and tea. The 'Traditional' pattern, consisting of food items commonly found in Brazilian food culture, and the 'Snack' pattern, characterised by the presence of sweets and highly processed foods, showed significant relationships with sociodemographic variables and nutritional quality of menus. Stimulating schools to provide meals that resemble the 'Traditional' pattern may contribute to the adoption of healthier dietary patterns, thus benefiting and strengthening health promotion through PNAE.

Diet can affect health directly or by altering the gut microbiota; thus, there are strong interrelationships between the gut immune system, gut microbiota and diet. This study examined the effects of ingesting AIN-93M purified diet (PD) on gut immune function and gut microbiota in DO11·10 mice, in which T cell-dependent and T cell-independent (TI) IgA can be analysed separately. Ingestion of the PD for 2 weeks reduced both T cell-dependent and TI secretory IgA in the faeces compared with non-PD, whereas the diet did not affect T cell-dependent and TI serum IgA. Ingestion of the PD had no effect on systemic immune system splenocyte responses. Ingestion of the PD reduced intestinal tissue expression levels of B-cell activating factor and A proliferation-inducing ligand, cytokines involved in TI-IgA production and polymeric Ig receptor, which transports IgA into the intestinal lumen. Co-abundance group (CAG) analysis of the intestinal microbiota was conducted based on correlations between changes in the abundance of bacterial genera, and the correlations between CAG and IgA were determined. The Allobaculum-dominated CAG expanded following ingestion of the PD, accompanied by an inverse correlation with the decrease in faecal IgA, whereas the Lactobacillus-dominated CAG shrank relative to the Allobaculum-dominated CAG. These results suggest that TI-IgA suppresses the expansion of some intestinal bacteria and that ingestion of the PD induces dysbiosis via impaired IgA secretion into the intestinal lumen.

This population-based cross-sectional study investigated the complex interplay of factors influencing high ultra-processed food (UPF) consumption among Brazilian adolescents using a hierarchical socio-ecological model. Data from 100 028 adolescents (13-17 years) enrolled in public and private schools nationwide were collected via self-administered questionnaires from the 2019 National School Health Survey. High UPF consumption was defined as ≥ 7 subgroups consumed on the previous day based on the NOVA classification. Poisson regression adjusted for complex sampling and hierarchical structure identified prevalence ratios (PR) for associated factors. High UPF consumption was significantly associated with younger age (PR = 1·22; 95 % CI 1·11, 1·34), regular breakfast consumption (PR = 1·32; 95 % CI 1·23, 1·42), regular screen time during meals (PR = 1·36; 95 % CI 1·27, 1·45), frequent UPF purchases at and around school (PR for canteen: 1·57; 95 % CI 1·43, 1·72; street vendors: 1·71; 95 % CI 1·55, 1·89), higher maternal education (PR 1·23, 95 % CI 1·12, 1·36) and lower parental supervision (PR 1·34, 95 % CI 1·11, 1·62). Living in the South (PR 1·50, 95 % CI 1·34, 1·69), Southeast (PR 1·30, 95 % CI 1·17, 1·44) and Midwest regions (PR 1·21, 95 % CI 1·09, 1·34) also correlated with higher consumption. Conversely, high body satisfaction and attending private school showed an inverse association. These findings underscore the intricate, multilevel influences on UPF consumption among Brazilian adolescents. Integrated interventions, spanning schools, family environments and public policies are crucial for promoting healthier eating habits and preventing obesity in this vulnerable population.

There is a lack of knowledge available on how cats adjust their macronutrient partitioning due to the consumption of single-macronutrient meals. The objective of this study was to evaluate consumption of a single meal of ingredients that contained foods of strictly carbohydrates (CHO), fat (FAT) or protein (PRO), on energy expenditure (EE) and macronutrient metabolism in cats. Ten domestic shorthair adult cats (1·9 years; 4·12 kg) were fed 22-24 g of chicken fat (FAT), 56-62 g of whey protein solution (PRO) or 54-56 g of cornstarch solution (CHO) for a single day in a randomised complete block design. Indirect calorimetry was conducted for 24 h post-feeding. Mean average EE over 24 h was highest in cats fed PRO (44 kcal/kg BW) and FAT (43 kcal/kg BW) compared with that in cats fed CHO (42 kcal/kg BW; P < 0·01). During 0 to 4 h, cats fed FAT had greater EE (49 kcal/kg BW), suggesting that cats respond to oxidising more dietary fat over protein in the early postprandial stage. Mean 24 h respiratory quotient (RQ) was greatest for cats fed CHO (0·76) followed by PRO (0·75) and FAT (0·74; P < 0·05). During 4 to 8 h, the RQ of cats fed PRO was the greatest (0·77), suggesting that cats initially increase gluconeogenesis from amino acids for subsequent glucose oxidation. In comparison to omnivores and herbivores, obligate carnivores have unique responses to single macronutrient intake, where they apparently generate energy from carbohydrate metabolism and rely more on gluconeogenic precursors.

While the effects of multidisciplinary weight loss (WL) on resting energy expenditure remain unclear in adolescents with obesity, the potential presence of adaptive thermogenesis (AT) has never been explored, which was the objective of the present work. Twenty-six adolescents (14·1 (sd 1·5) years) with severe obesity completed a 9-month inpatient multidisciplinary intervention followed by a 4-month follow-up. Anthropometric measurements, body composition (dual X-ray absorptiometry) and resting energy expenditure (REE, indirect calorimetry) were assessed before (T0) and after 9 months of WL intervention (T1) and after a 4-month follow-up (T2). AT, at the level of REE, was defined as a significantly lower measured v. predicted (using regression models with baseline data) REE. Two pre-cited REE equations were used, using both fat mass and fat-free mass (FFM) (predicted REE using equation 1) or FFM only (predicted REE using equation 2). Measured and predicted REE significantly decreased between T0 and T1 (P < 0·001) and remained lower at T2 compared with T0 (measured REE: P = 0·017; predicted REE: P < 0·001). Predicted REE using equation 2 was significantly higher than measured REE at T1 (P = 0·012), suggesting the presence of AT. FFM at T0 was negatively correlated with ATp1T1 (Rho = -0·428; P = 0·033) and ATp2T1 (Rho = -0·485; P = 0·014). The variation of FFM between T0 and T1 was negatively correlated with AT at T1 and T2. These preliminary results suggest the existence of AT in response to WL in adolescents with obesity, independently of the degree of WL. AT was associated with subsequent body weight and fat regain, suggesting AT may represent a damper to WL attempts while increasing the adolescents' risks for subsequent weight and adiposity rebounds.