Use of a Web-Based Dietary Assessment Tool (RiksmatenFlex) in Swedish Adolescents: Comparison and Validation Study

Assessing the relative validity of a web-based self-administered 24-hour dietary recall in a Canadian adolescent's population

BACKGROUND

Healthy eating habits at a young age are crucial to support growth and development and good general health. In this context, monitoring youth dietary intakes adequately with valid tools is important to develop efficient interventions and identify groups that are more at risk of inadequate intakes. This study aimed to assess the relative validity of the self-administered web-based 24-h dietary recall (R24W) for evaluating energy and nutrient intakes among active adolescents.

METHODS

Participants were invited to complete one interviewer-administered 24-h dietary dietary recall and the R24W on up to three occasions within one month. A total of 272 French-speaking active adolescents aged 12 to 17 years from the province of Québec were invited to complete three R24W and one interview-administered 24-h recall. Student's t-test and correlations were conducted on sex-adjusted data. Percent differences, cross-classification (percentage of agreement), weighted Kappa and Bland-Altman plots were calculated.

RESULTS

Mean (SD) energy intake from the R24W was 8.8% higher than from the interview-administered 24-h dietary recall (2558 kcal ± 1128 vs. 2444 kcal ± 998, p < 0.05). Significant differences in mean nutrient intake between the R24W and the interview-administered 24-h dietary recall ranged from 6.5% for % E from fat (p < 0.05) to 25.2% for saturated fat (p < 0.001), i.e., higher values with R24W. Sex-adjusted correlations were significant for all nutrients except for % E from proteins and thiamin (range: 0.24 to 0.52, p < 0.01). Cross-classification demonstrated that 36.6% of the participants were classified in the same fourth with both methods, 39.6% in the adjacent fourth, and 5.7% misclassified. Bland-Atman plots revealed proportional bias between the two methods for 7/25 nutrients. Completing at least two recalls with the R24W increased the precision of intake estimates.

CONCLUSION

These data suggest that the R24W presents an acceptable relative validity compared to a standard interview-administered 24-h recall for estimating energy and most nutrients in a cohort of French-speaking adolescents from the province of Québec.

AI nutritionist: Intelligent software as the next generation pioneer of precision nutrition

With the rapid development of information technology and artificial intelligence (AI), people have acquired the abilities and are encouraged to develop intelligent tools and software, which begins to shed light on intelligent and precise food nutrition. Despite the rapid development of such software, disparities still exist in terms of methodology, contents, and implementation strategies. Hence, a set of panoramic profiles is urgently needed to elucidate their values and guide their future development. Here a comprehensive review was conducted aiming to summarize and compare the objects, contents, intelligent algorithms, and functions realized by the already released software in current research. Consequently, 177 AI nutritionists in recent years were collected and analyzed. The advantages, limitations, and trends concerning their application scenarios were analyzed. It was found that AI nutritionists have been gradually advancing the production modes and efficiency of food recognition, dietary recording/monitoring, nutritional assessment, and nutrient/recipe recommendation. Most AI nutritionists have a relatively low level of intelligence. However, new trends combining advanced AI algorithms, intelligent sensors and big data are coming with new applications in real-time and precision nutrition. AI models concerning molecular-level behaviors are becoming the new focus to drive AI nutritionists. Multi-center and multi-level studies have also gradually been realized to be necessary.

Estimation of intake and quantification of hemoglobin adducts of acrylamide in adolescents in Sweden

Blood samples (n = 600) from participants in the Swedish dietary survey Riksmaten Adolescents 2016-17 were analyzed with respect to hemoglobin (Hb) adducts from acrylamide (AA) and its metabolite glycidamide (GA) as biomarkers of internal dose/exposure. The results are presented from statistical analyses of food consumption data (2-day dietary recall and questionnaires) and measured Hb adduct levels. The estimated exposure as well as consumption data were examined in relation to non-dietary factors such as sex, age (group medians of 12, 15, and 18 years), place of residence (urban/rural), smoking status, and parental education level. The median AA adduct level was estimated to be 34 pmol/g Hb (range 14-225). No significant difference was found for place of residence, parental education, sex, or age. A significant difference was found between the median adduct levels of daily smokers (n = 8) and never smokers (n = 323) in the older age groups, but not between occasional smokers (n = 47) and never smokers. The median differences between daily smokers and never smokers were 76, 40, and 128 pmol/g Hb for AA, GA, and AA + GA, respectively. The median AA intake for the whole group of adolescents, as estimated from dietary recall data combined with reported concentrations in food, was 0.40 μg/kg bw/day. The corresponding median intake estimated from measured Hb adduct levels of AA was 0.20 μg/kg bw/day. A significant, although low, positive Spearman correlation was found between the two intake estimates (p-value = 8 × 10-3; ρ = 0.11). From the estimated intake of AA from food frequency questionnaires, significance was found for the 15-year-old children with higher AA adduct levels observed at higher consumption frequencies of fried potatoes/French fries. AA is considered a genotoxic carcinogen. For the estimated intake of AA for any age group and method (dietary recall or AA adduct), both a calculated margin of exposure as well as lifetime quantitative cancer risk estimates indicate health concern. A future study on food consumption designed with respect to AA exposure would provide a better understanding of the correlation between consumption and exposure and should give a more reliable estimate of the contribution of dietary AA to the overall cancer risk.

Validity of dietary assessment methods compared with doubly labeled water in children: A systematic review and meta-analysis

OBJECTIVES

We aimed to validate dietary assessment methods against the gold standard, doubly labeled water (DLW), for estimating total energy intake (TEI).

METHODS

PubMed, Scopus, Web of Science, and Google Scholar databases were searched until May 2023. Inclusion criteria encompassed studies involving participants aged 1-18 years, employing dietary assessment methods like food records, dietary histories, food frequency questionnaire (FFQ), or 24-h recalls estimating TEI alongside DLW to measure total energy expenditure (TEE). Data were pooled using random-effects meta-analysis models.

RESULTS

Thirty-three studies were identified, with sample sizes ranging from 9 to 118 participants. Meta-analysis of 22 studies identified underestimation of TEI (mean difference [MD] = -262.9 kcal/day [95% CI: -380.0, -145.8]; I2 = 93.55%) for food records compared with TEE estimated by DLW. Other dietary assessment methods, including food recalls (n = 9) (MD = 54.2 kcal/day [95% CI: -19.8, 128.1]; I2 = 49.62%), FFQ (n = 7) (MD = 44.5 kcal/day [95% CI: -317.8, 406.8]; I2 = 94.94%), and diet history (n = 3) (MD = -130.8 kcal/day [95% CI: -455.8, 194.1]; I2 = 77.48%), showed no significant differences in TEI compared with DLW-estimated TEE. All studies were of high quality.

CONCLUSION

Food records may underestimate TEI, yet additional research is needed to identify the most accurate methods for assessing children's dietary intake.

Comparing the web-based and traditional self-reported 24-hour dietary recall data in the PakNutriStudy

BACKGROUND

The flaws in dietary assessment methods can generate misleading information and thus may impact on the interventions planned based on that information. Context specific digitalization of dietary assessment tools is a potential way forward to reduce biases and resources involved in data handling.

METHODS

Two versions of Twenty-Four Hour Recall (24HR) (traditional [24HR Ver-01] and digital [24HR Ver-02]) were tested for data agreement and feasibility by gathering cross sectional paired data on both the versions from 102 participants (18-25 years age). The web based 24HR was setup using the system of Intake24 (New Castle University) with incorporation of South Asian food data base for beverages.

RESULTS

The data sets obtained from 24HR Ver-01 and 24HR Ver-02 on beverage consumption (food items as well as portion sizes) were compared for agreement. The highest percentage of agreement of food item reporting between 24HR Ver-01 and 24HR Ver-01 was during the lunch time. The average kappa value (κ =0.375833) for all the meals indicated a fair agreement betweenVer-01 and 24HR Ver-02 The correlation of portion sizes reported using 24HR Ver-01 and 24 HR Ver-02 was statisticallysignificant for morning snack, lunch and dinner (r = 0.465; r = 0.324; r = 0.407 respectively). According to Bland Altman plot, least agreement between the two versions was found in the portion sizes reported for morning snacks. Data collectors found 24 HR Ver-02 easier in terms of data processing but it was regarded time taking and less convenient by the participants.

CONCLUSION

The Intake 24 (digital version of 24HR) can be a preferred tool of data collection as the data collected through it may reach fairly good levels of accuracy. Future directions for research like conducting a follow up study with cross over design, expanding the study using food items other than beverages, and testing the digital dietary assessment tool against an objective gold standard of dietary intake can be helpful in reaching more conclusive evidence.

Low concentrations of perfluoroalkyl acids (PFAAs) in municipal drinking water associated with serum PFAA concentrations in Swedish adolescents

While highly contaminated drinking water (DW) is a major source of exposure to perfluoroalkyl acids (PFAAs), the contribution of low-level contaminated DW (i.e. < 10 ng/L of individual PFAAs) to PFAA body burdens has rarely been studied. To address this knowledge gap, we evaluated the association between concentrations of perflurooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS), and their sum (∑4PFAAs) in DW and serum in Swedish adolescents using weighted least squares regression. We paired serum PFAA concentrations in adolescents (age 10-21 years, n = 790) from the dietary survey Riksmaten Adolescents 2016-17 (RMA) with mean PFAA concentrations in water samples collected in 2018 from waterworks (n = 45) supplying DW to the participant residential and school addresses. The median concentrations of individual PFAAs in DW were < 1 ng/L. Median concentrations of PFNA and PFHxS in serum were < 1 ng/g, while those of PFOA and PFOS were 1-2 ng/g. Significant positive associations between PFAA concentrations in DW and serum were found for all four PFAAs and ∑4PFAAs, with estimated serum/DW concentration ratios ranging from 210 (PFOA) to 670 (PFHxS), taking exposure from sources other than DW (background) into consideration. The mean concentrations of PFHxS and ∑4PFAA in DW that would likely cause substantially elevated serum concentrations above background variation were estimated to 0.9 ng/L and 2.4 ng/L, respectively. The European Food Safety Authority has determined a health concern concentration of 6.9 ng ∑4PFAAs/mL serum. This level was to a large degree exceeded by RMA participants with DW ∑4PFAA concentrations above the maximum limits implemented in Denmark (2 ng ∑4PFAAs/L) and Sweden (4 ng ∑4PFAAs/L) than by RMA participants with DW concentrations below the maximum limits. In conclusion, PFAA exposure from low-level contaminated DW must be considered in risk assessment for adolescents.

Validation of Dietary Intake Estimated by Web-Based Dietary Assessment Methods and Usability Using Dietary Records or 24-h Dietary Recalls: A Scoping Review

The goal was to summarize studies comparing the accuracy of web-based dietary assessments with those of conventional face-to-face or paper-based assessments using 24-h dietary recall or dietary record methods in the general population. Using two databases, mean differences and correlation coefficients (CCs) for intakes of energy, macronutrients, sodium, vegetables, and fruits were extracted from each study independently by the authors. We also collected information regarding usability from articles reporting this. From 17 articles included in this review, the mean dietary intake differences in the web-based dietary assessment compared to conventional methods, were -11.5-16.1% for energy, -12.1-14.9% for protein, -16.7-17.6% for fat, -10.8-8.0% for carbohydrates, -11.2-9.6% for sodium, -27.4-3.9% for vegetables, and -5.1-47.6% for fruits. The CC was 0.17-0.88 for energy, protein, fat, carbohydrates, and sodium, and 0.23-0.85 for vegetables and fruits. In three out of four studies reporting usability, more than half of the participants preferred the web-based dietary assessment. In conclusion, % difference and CC of dietary intake were acceptable in both web-based dietary records and 24-h dietary recalls. The findings from this review highlight the possibility of wide-spread application of the web-based dietary assessment in the future.

Consumption of foods with the Keyhole front-of-pack nutrition label: potential impact on energy and nutrient intakes of Swedish adolescents

OBJECTIVE

The Keyhole is an internationally recognised front-of-pack nutrition label, guiding consumers to healthier food options. It indicates products in accordance with specific criteria for dietary fats, sugars, fibres, salt and wholegrains. The objective of this study was to simulate the potential impact of the Keyhole on adolescents' energy and nutrient intakes by modelling a shift from reported food intakes to foods meeting the Keyhole criteria.

DESIGN

Self-reported dietary intake data were derived from a cross-sectional survey. Multiple replacement scenarios were calculated, where foods meeting the Keyhole criteria replaced reported non-compliant foods with varying proportions of replacement.

SETTING

Dietary survey 'Riksmaten Adolescents 2016-2017' in schools across Sweden.

PARTICIPANTS

A nationally representative sample of 3099 adolescents in school years 5, 8 and 11 (55 % girls).

RESULTS

Overall, replacement with foods meeting the Keyhole criteria led to more adolescents meeting nutrition recommendations. Largest median intake improvements were seen for wholegrains (+196 %), SFA (-13 %), PUFA (+17 %) and fibres (+15 %). Smallest improvements were seen for free sugars (-3 %) and salt (-2 %), partly explained by the ineligibility of main food sources of free sugars for the Keyhole, and non-inclusion of ready meals that are often high in salt. Most micronutrient intakes were stable or improved. Unintentional effects included decreases in vitamin A, MUFA and energy intakes. Largest potential improvements in fat and fibre sources were observed in the youngest age group.

CONCLUSIONS

A shift to Keyhole alternatives for everyday foods would improve adolescents' nutrient intakes, even with smaller exchanges.

Healthy eating index and diet diversity score as determinants of serum perfluoroalkyl acid (PFAA) concentrations in a national survey of Swedish adolescents

Food is an important source of perfluoroalkyl acid (PFAA) exposure for the general adult population, but few data exist for adolescents. Healthy food habits established during adolescence may positively influence health later in life. Associations between serum PFAA concentrations and a healthy eating index (SHEIA15), as well as a diet diversity score (RADDS), were determined in a nationally representative adolescent population from Sweden (Riksmaten Adolescents 2016-2017, RMA). Using consumption data from food registrations and frequency questionnaires, we additionally analyzed associations with commonly consumed food groups. Associations were analyzed by fitting a cumulative probability model using ordinal regression. Among the seven PFAAs detected in ≥70% of the 1098 participants (age 10-21 years), median concentrations ranged from <1 ng/g serum of perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perflurorundecanoic acid (PFUnDA), linear (lin-) perfluorohexanesulfonic acid (PFHxS) and branched (br-) perfluorooctanesulfonic acid (PFOS) to 1-2 ng/g serum of lin-perfluorooctanoic acid (PFOA) and lin-PFOS. PFNA, PFDA, PFUnDA and lin-PFOS concentrations were positively associated with both SHEIA15 and RADDS, a finding most likely driven by higher consumption of seafood. PFDA, PFUnDA and lin-PFOS concentrations were positively related to commonly consumed fish/shellfish groups, such as lean marine fish and shellfish. Inverse associations between PFAA concentrations and dairy consumption suggest an underlying factor behind dairy consumption that similarly affects adolescent exposure to the different PFAAs. Isomeric differences in dietary exposure between lin-PFOS and br-PFOS were suggested, as br-PFOS concentrations, in contrast to lin-PFOS, were not associated with SHEIA15, RADDS and consumption of different food groups. We conclude that Swedish adolescents, adhering to a diverse and healthy diet, appears to be more highly exposed to legacy PFAAs than those eating less healthy. Additional research is necessary for a better understanding of the health implications of healthy eating from a PFAA exposure perspective.

Investigation of the Associations between Diet Quality and Health-Related Quality of Life in a Sample of Swedish Adolescents

Most adolescents do not consume a high-quality diet, while self-reported mental health problems within this group are increasing. This study aimed to investigate the association between diet quality and health-related quality of life, and to explore the differences in diet quality and health-related quality of life between gender and parental education status. In this cross-sectional study, a detailed web-based recall method was implemented to determine dietary intake, which was analysed using the newly developed Swedish Healthy Eating Index for Adolescents 2015 (SHEIA15) and the Riksmaten Adolescents Diet Diversity Score (RADDS), to determine diet quality. The KIDSCREEN-10 questionnaire was used to measure health-related quality of life, and parental education was self-reported through questionnaires. Parental education was divided into two groups: ≤12 years or >12 years. The study included 1139 adolescents from grade 7 (13−14 years old), 51% were girls. The results showed that girls had higher scores for healthy eating and diet diversity but lower scores for health-related quality of life. A positive association was found between diet diversity and health-related quality of life (Adj R2 = 0.072, p = 0.001), between vegetable/fruit consumption and health-related quality of life (Adj R2 = 0.071, p = 0.002), and between healthy eating and diet diversity (Adj R2 = 0.214, p < 0.001). No association was found between healthy eating and health-related quality of life for all participants. The mean scores for healthy eating and diet diversity were significantly higher in the higher education parental group. In conclusion, higher diet diversity and increased fruit and vegetable consumption could be a strategy to improve health-related quality of life among adolescents. There is a need to promote better diet quality, especially in households of low parental education. In addition, there is a further need to investigate the potential benefits of improved diet quality on mental health and overall well-being.

Vitamin D status and associations with diet, objectively measured physical activity patterns and background characteristics among adolescents in a representative national cross-sectional survey

OBJECTIVE

To report on vitamin D status, measured as plasma 25-hydroxyvitamin D concentration (25(OH)D), the prevalence of vitamin D insufficiency and deficiency, and to explore associations between vitamin D status and background characteristics.

DESIGN

Data were collected in a National Dietary Survey, Riksmaten adolescents 2016-2017. The participants completed dietary assessments and questionnaires on the web and wore accelerometers. (25(OH)D) was measured with a MS method.

SETTING

Representative survey conducted in schools throughout Sweden.

PARTICIPANTS

Participants attended school years 5 (Y5, mean age 12. 5 years), 8 (Y8, mean age 14. 5 years) and 11 (Y11, mean age 18 years), and included 1100 participants.

RESULTS

Overall, there was no difference in plasma 25(OH)D between girls and boys. Vitamin D insufficiency differed between the three school years. The prevalence of insufficiency in Y5 was 32 (boys) and 48 (girls) percent, while in Y11 62 (boys) and 43 (girls) percent. The prevalence of deficiency in Y11 was 16 and 15 % in boys and girls, respectively. Being born outside of Sweden was associated with a 10-fold increased risk of being vitamin D deficient. Deficiency was also associated with longer time spent in sedentary intensity, a lower consumption of fortified dairy products and fats and oils.

CONCLUSIONS

Vitamin D deficiency was most common in the oldest age group and being born outside of Sweden increased the risk of being deficient. The present study will form a baseline for future follow-up studies of the implementation of a new mandatory vitamin D fortification policy in 2018.

Demographic, life-style and physiological determinants of serum per- and polyfluoroalkyl substance (PFAS) concentrations in a national cross-sectional survey of Swedish adolescents

PER: and polyfluoroalkyl substances (PFAS) may affect adolescent health, yet factors related to PFAS concentrations in serum are poorly understood. We studied demographic, life-style and physiological determinants of serum PFAS concentrations in Swedish adolescents from a nation-wide survey, Riksmaten Adolescents 2016-17 (RMA, age 10-21 years, n = 1098). Serum samples were analyzed for 42 PFAS, using liquid chromatography-tandem mass spectrometry. The cumulative probability model was used to estimate associations between serum PFAS and determinants, using ordinal logistic regression. Legacy linear (lin-) perfluorooctanoic acid (PFOA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), lin-perfluorohexanesulfonic acid (PFHxS) and lin-/branched (br-) perfluorooctanesulfonic acid (PFOS) were quantifiable in ≥70% of the samples. The emerging PFAS 9-chlorohexanedecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) was quantified in 5.4% of the samples, suggesting initiation of long-range transport far from production sites. Median concentrations of all legacy PFAS were <2 ng/g serum, with a few participants having very high (>100 ng/g serum) lin-PFHxS and lin-/br-PFOS concentrations due to previous high exposure from PFAS-contaminated drinking water. Legacy PFAS exposure was strongly associated with birth country of the participants and their mothers. 2-fold higher estimated adjusted mean (EAM) concentrations were seen among high income country participants with mothers from high income countries than among low/lower-middle income country participants with mothers from the same category. Menstruating females had lower br-PFOS EAM concentrations than those who were not. Iron status (plasma ferritin) among females may be a marker of intensity of menstrual bleeding, but it was not significantly associated with legacy PFAS concentrations among females. Further studies are needed to determine how physiological changes occurring around menstruation affect the toxicokinetics of PFAS in females. In conclusion, PFAS are pollutants of the industrialized world and some of the identified determinants may be overlooked confounders/effect modifiers that should be included in future PFAS/health studies among adolescents.

Leisure-time organised physical activity and dietary intake among Swedish adolescents

This study aimed to investigate associations between participation in leisure-time organised physical activity (LTOPA) and dietary intake in a large representative sample of Swedish adolescents participating in the national dietary survey Riksmaten Adolescents 2016-2017. A sample of 2807 participants aged 11-12, 14-15 and 17-18 years were included. Information about LTOPA and dietary intake were collected through questionnaires and two 24-hour recalls on the web (RiksmatenFlex). For dietary intake, overall healthy eating index, intake of fruit, vegetables, candy, sugar-sweetened beverages, and the proportion of added sugar to total energy intake were analysed. Significance-testing for associations was performed with analysis of covariance. LTOPA was associated with lower sugar-sweetened beverages intake among adolescent boys (p < 0.001, ηp2 = 0.012) and girls (p = 0.007, ηp2 = 0.005), higher fruit intake among boys (p = 0.043, ηp2 = 0.003), and lower vegetable intake among girls (p < 0.001, ηp2 = 0.009). However, LTOPA was unrelated to the overall healthy eating index, candy intake, and the proportion of added sugar to total energy intake (p > 0.05). LTOPA was only associated with some healthy eating behaviours, and there is much room for improvement in the diets of Swedish adolescents.

Breakfast Habits and Associations with Fruit and Vegetable Intake, Physical Activity, Sedentary Time, and Screen Time among Swedish 13-14-Year-Old Girls and Boys

This study explored whether breakfast habits were associated with intake of fruits and vegetables, minutes in moderate-to-vigorous physical activity (MVPA), minutes spent sedentary, and screen time among adolescents. Cross-sectional data were collected among 13–14-year-old boys and girls (n = 1139). Breakfast habits and screen time were determined via questionnaire, fruit and vegetable intake were determined through dietary recall, and physical activity and sedentary time were determined via accelerometers. Multilevel mixed models and general estimation equation models were applied. Almost 40% of participants skipped breakfast at least one day of the week. Participants with irregular breakfast habits on weekdays had lower fruit and vegetable consumption by 26.7 g (95% CI = −49.3, −5.9) while irregular breakfast habits during the whole week were associated with higher levels of screen time (OR = 1.5, 95% CI = 1.1, 2.1) compared to regular breakfast habits. Girls with irregular breakfast habits on weekdays had 7.7 min more sedentary time (95% CI = 0.8, 15.7) than girls with regular breakfast habits, while the opposite was found in boys (β = −13.3, 95% CI = −25.3, −2.6)). No significant associations were found for MVPA. Regular breakfast habits should be encouraged, as they might contribute to a higher intake of fruit and vegetables and are associated with lower levels of screen time, although further studies are necessary to establish causation.

Potential of existing online 24-h dietary recall tools for national dietary surveys

OBJECTIVE

To describe existing online, 24-h dietary recall (24-h DR) tools in terms of functionalities and ability to tackle challenges encountered during national dietary surveys, such as maximising response rates and collecting high-quality data from a representative sample of the population, while minimising the cost and response burden.

DESIGN

A search (from 2000 to 2019) was conducted in peer-reviewed and grey literature. For each tool, information on functionalities, validation and user usability studies, and potential adaptability for integration into a new context was collected.

SETTING

Not country-specific.

PARTICIPANTS

General population.

RESULTS

Eighteen online 24-h DR tools were identified. Most were developed in Europe, for children ≥10 years old and/or for adults. Eight followed the five multiple-pass steps but used various methodologies and features. Almost all tools (except three) validated their nutrient intake estimates, but with high heterogeneity in methodologies. User usability was not always assessed, and rarely by applying real-time methods. For researchers, eight tools developed a web platform to manage the survey and five appeared to be easily adaptable to a new context.

CONCLUSIONS

Among the eighteen online 24-h DR tools identified, the best candidates to be used in national dietary surveys should be those that were validated for their intake estimates, had confirmed user and researcher usability, and seemed sufficiently flexible to be adapted to new contexts. Regardless of the tool, adaptation to another context will still require time and funding, and this is probably the most challenging step.

Designing Nutritionally Adequate and Climate-Friendly Diets for Omnivorous, Pescatarian, Vegetarian and Vegan Adolescents in Sweden Using Linear Optimization

Low-carbon diets can counteract climate change and promote health if they are nutritionally adequate, affordable and culturally acceptable. This study aimed at developing sustainable diets and to compare these with the EAT-Lancet diet. The Swedish national dietary survey Riksmaten Adolescents 2016–2017 was used as the baseline. Diets were optimized using linear programming for four dietary patterns: omnivores, pescatarians, vegetarians and vegans. The deviation from the baseline Riksmaten diet was minimized for all optimized diets while fulfilling nutrient and climate footprint constraints. Constraining the diet-related carbon dioxide equivalents of omnivores to 1.57 kg/day resulted in a diet associated with a reduction of meat, dairy products, and processed foods and an increase in potatoes, pulses, eggs and seafood. Climate-friendly, nutritionally adequate diets for pescatarians, vegetarians and vegans contained fewer foods and included considerable amounts of fortified dairy and meat substitutes. The optimized diets did not align very well with the food-group pattern of the EAT-Lancet diet. These findings suggest how to design future diets that are climate-friendly, nutritionally adequate, affordable, and culturally acceptable for Swedish adolescents with different dietary patterns. The discrepancies with the EAT diet indicate that the cultural dietary context is likely to play an important role in characterizing sustainable diets for specific populations.

The Contribution of Foods and Beverages of Low Nutritional Value to the Diets of Swedish Adolescents, by Food Group, Time and Place. A Nationally Representative Study

Adolescence is a time in life when lifestyle behaviours are acquired. One indicator of poor diet quality is the intake of foods and beverages with a relatively low nutritional value. Using the Australian classification of such foods, termed "discretionary", we classified the intakes of Swedish adolescents who participated in the Riksmaten Adolescent 2016-17 national dietary survey. From selected schools, 3099 adolescents in age groups 11-12, 14-15 and 17-18 years provided two 24-h recalls. Intakes and healthy dietary scores were calculated. Plasma ferritin, folate and 25(OH)D were available for a third. Almost 40% of total energy came from discretionary foods/beverages. Adolescents with higher intakes were more likely to be female, older, from a low socioeconomic position-household and born in Sweden. Most discretionary foods/beverages were consumed on weekend days and during in-between meals, outside of the home and at school. Percent energy from discretionary intake was associated with healthy dietary scores but not nutritional status. A substantial amount of energy was obtained from discretionary foods/beverages, and we found that consumption is pervasive across sociodemographic factors, time and place. Addressing this pattern will require a comprehensive approach to food environments and behaviours to reach all adolescents in an equitable manner.

Cadmium, total mercury, and lead in blood and associations with diet, sociodemographic factors, and smoking in Swedish adolescents

BACKGROUND

Despite their vulnerability to the toxic effects of certain metals, biomonitoring data on adolescents are limited. In the present study, we assessed blood concentrations of toxic metals (cadmium [Cd], total mercury [Hg], and lead [Pb] in a national representative sample of Swedish adolescents. We also examined the associations of Cd, total Hg and Pb with habitual intakes of major energy-providing food groups and other possible determinants such as age, sex, household education, Nordic or non-Nordic origin, and smoking.

METHODS

We analysed blood concentrations of Cd, total Hg, and Pb in a sample of 1099 adolescents from the Riksmaten Adolescents 2016-17 study in three age groups (mean age of 12, 15, and 18 years) using inductively coupled plasma mass spectrometry. The participants completed web-based questionnaires on food consumption frequency, sociodemographic factors and health status. Dietary data from two web-based 24-h dietary recalls were used to estimate the habitual intake of 10 major food groups.

RESULTS

Almost all participants had detectable concentrations of Cd, total Hg, and Pb in whole blood. The median blood concentrations were 0.12 μg/L for Cd, 0.72 μg/L for total Hg, and 7.1 μg/L for Pb. Higher blood concentrations of Cd were observed in girls than in boys, whereas concentrations of total Hg and Pb were higher in boys. We observed an inverse association between Cd and meat intake. Total Hg concentrations were positively associated with intakes of fish, eggs, meat, and vegetables, and Pb concentrations were inversely associated with intakes of dairy products. Furthermore, smokers had higher concentrations of Cd and Pb.

CONCLUSIONS

We found that fish was a potentially important source of exposure to total Hg in Swedish adolescents. No other food group was identified to have a strong impact on the blood levels of Cd, total Hg and Pb. Thirteen per cent of the adolescents had blood Pb concentrations above 12 μg/L, the reference point used in the risk assessment of Pb by the European Food Safety Authority (EFSA).

Sustainable and acceptable school meals through optimization analysis: an intervention study

Background

School meals hold considerable potential to shape children’s diets and reduce food-related greenhouse gas emissions (GHGE)—in the short and long term. This study applied linear optimization to develop a GHGE-reduced, nutritionally adequate, and affordable school lunch menu. The effects on food waste, consumption and pupils’ satisfaction with the meals were evaluated.

Methods

A pre-post design was employed to assess the effects of implementing an optimized lunch menu on daily food waste, consumption, and pupils’ school meal satisfaction in three schools (grades 0–9) from one Swedish municipality. A food list containing amounts, prices, nutrient content, and GHGE-values of all foods used for a previously served (baseline) four-week lunch menu was created. Using linear programming, this food list was optimized for minimum deviation and constrained to ensure nutritional adequacy and a reduced climate impact. The optimized food list was developed into a new (intervention) four-week lunch menu by a professional meal planner, following the baseline menu as closely as possible. The baseline and intervention menus were served for four weeks, respectively, with a two week break in between. Prepared, wasted and leftover food were weighed daily by the school kitchen staff during both periods. Interrupted time series analysis assessed mean and slope differences in daily food waste and consumption between the two periods. School lunch satisfaction was assessed with an online questionnaire at baseline and during the intervention.

Results

Optimization resulted in a food list that was 40% lower in GHGE, met all nutrient recommendations for school meals, and cost 11% less compared to baseline. The intervention menu was served as planned, with only minor changes required (for practical reasons). Plate waste, serving waste, consumption and school lunch satisfaction did not differ significantly from baseline, in any of the schools.

Conclusions

The findings demonstrate that school meals can successfully be improved regarding health and environmental sustainability using linear optimization, without negative effects on food waste, consumption or cost. This approach offers the necessary flexibility to tailor menus towards different priorities and could therefore be transferred to other types of meal services.

Trial registration

The trial is registered at clinicaltrials.gov (NCT04168632 Fostering Healthy and Sustainable Diets Through School Meals (OPTIMAT).

Mycotoxins in blood and urine of Swedish adolescents-possible associations to food intake and other background characteristics

The exposure to mycotoxins of Swedish adolescents is currently unknown. The aim of the present study was to investigate the exposure to mycotoxins and their association with food intake, and background characteristics in adolescents of a national dietary survey. About 3000 school students (1000 from the 5th, 8th and 11th school years) were recruited for the survey. The participants completed Web-based questionnaires on food propensity, sociodemography and health, and a Web-based dietary recall. Spot urine and blood samples were collected from 1105 of the participants for mycotoxin biomarker analysis. Mycotoxins were analysed with multibiomarker methods in urine (HPLC-MS/MS) and serum (HPLC-MS/MS). Of the 35 different analytes in urine, the frequency of positive samples were the following: deoxynivalenol (DON, 4.8%), DON-15-β-D-O-glucuronide (DON-15GlcA, 9.1%), dihydro-citrinone (DH-CIT, 0.5%), HT-2-glucuronide (HT-2-3-GlcA, 0.1%) and ochratoxin A (OTA, 0.1%). Of the 27 different analytes in serum, OTA was detected in all samples, while 2'R-ochratoxin A (2'R-OTA) was found in 8.3% and enniatin B (EnB) in 99.2% of the samples. Exposure assessment calculations were performed on OTA from the serum concentration and on DON equivalents (DON eqv) from the urine concentration. All probable daily intake (PDI) estimates were below tolerable daily intakes, except for 1.6% of the participants for DON. The maximum PDI was 4.3 μg DON eqv/kg body weight and day. Consumption of cereal grain commodities was associated with levels of DON, EnB or OTA in biofluids. Serum OTA was also associated with intakes of raisins and coffee. Furthermore, coffee consumption correlated well with 2'R-OTA concentration in serum. In conclusion, exposure to mycotoxins in Swedish adolescents is common, but fortunately, high exposure was rare.

The importance of school lunches to the overall dietary intake of children in Sweden: a nationally representative study

Objective:

School lunches have potential to foster healthy diets in all children, but data on their importance are relatively scarce. The current study aimed to describe the dietary intake from school lunches by sex and school grade, and to assess how the daily intake, school lunch intake and the daily intake provided by lunch differ by sex and parental education.

Design:

Cross-sectional. All foods and drinks consumed for 1–3 weekdays were self-reported. Energy, absolute and energy-adjusted intakes of nutrients and food groups were calculated per weekday and per school lunch. Mixed-effects linear models assessed sociodemographic differences in dietary intakes. Nutrient and energy density at lunch and during the rest of the day were compared.

Setting:

Seventy-nine Swedish primary schools.

Participants:

Pupils in grades 5 and 8 (N 2002), nationally representative.

Results:

Lunch provided around half of daily vegetable intake and two-thirds of daily fish intake. Nutrient density was higher and energy density lower at lunch compared with the rest of the day (P < 0·001). Boys had greater energy-adjusted intakes of red/processed meat and lower intakes of vegetables and dietary fibre compared with girls (P < 0·001), overall and at lunch. Daily energy-adjusted intakes of most nutrients/food groups were lower for pupils of lower-educated parents compared with pupils of parents with higher education, but at lunch, only Fe and fibre intakes were significantly lower in this group.

Conclusions:

School lunches are making a positive contribution to the diets of Swedish children and may mitigate well-established sex differences and social inequalities in dietary intake.

Diet diversity score and healthy eating index in relation to diet quality and socio-demographic factors: results from a cross-sectional national dietary survey of Swedish adolescents

Objective:

Groups with low socio-economic status have less healthy diets and higher prevalence of non-communicable diseases. Using the latest Swedish national dietary survey data, we developed a healthy eating index and a diet diversity score with the aim to explore associations between the scores and socio-demographic factors.

Design:

Cross-sectional national dietary survey. A web-based retrospective registration of food and beverages during 2 d was used to assess dietary intake. This information was used to construct the Swedish Healthy Eating Index for Adolescents 2015 (SHEIA15) and the Riksmaten Adolescents Diet Diversity Score (RADDS). The scores were based on the latest Swedish dietary guidelines from 2015. Intakes of food and nutrients across the scores were examined. Mixed-effects multilevel models were used to assess associations between the scores and household education, sex, school grade, weight status and school municipality.

Setting:

School-based survey in Sweden.

Participants:

2905 adolescents in grades 5, 8 and 11, 56 % girls.

Results:

High scores on SHEIA15 and RADDS were associated with higher intake of vegetables, fish and several nutrients, and lower intake of sugar-sweetened beverages and red meat. Boys and participants in households with lower education level scored lower on both indices. Individuals with overweight/obesity scored lower on RADDS.

Conclusions:

The newly developed indices can be used to identify healthy eating patterns among Swedish adolescents. Both indices show that boys and adolescents from households with lower education level have poorer dietary habits. Lower diet diversity was related to overweight/obesity, but the overall healthy eating index was not.