Anna Karin Lindroos

Background: Sweden expanded its mandatory vitamin D fortification program in 2018 addressing high rates of insufficient vitamin D status and low intake. This study aimed to assess vitamin D status among young children post-expansion, evaluate its determinants, and identify main vitamin D sources and their climate impact. Methods: Dietary intake among 18-month-olds (18mo, n = 1074) and 4-year-olds (4yo, n = 746) were obtained from the Swedish national survey Riksmaten Young Children 2021-24 based on two non-consecutive 24-hour food records. Intake of vitamin D from drops (µg/d) was also recorded. Individual vitamin D intakes were adjusted using the Multiple Source Method to reflect habitual intake. Blood concentrations of 25-hydroxyvitamin D (25OHD) were provided for a subset (18mo, n = 281; 4yo, n = 270). Climate impact was expressed as greenhouse gas emissions (GHGEs) in carbon dioxide equivalents (CO₂ eq), using life cycle assessment data from the Research Institutes of Sweden. Associations between 25OHD and plausible determinants were analyzed with linear regression. Results: 16% of 18mo and 61% of 4yo had total vitamin D intakes (including diet and drops) below the average requirement, 7.5 µg/d. None were deficient (25OHD < 30 nmol/l), and 7% of 18mo and 4% of 4yo were insufficient (< 50 nmol/l). 25OHD was positively associated with dietary vitamin D intake and vitamin D from drops, and inversely associated with blood sampling during winter and parents’ birth country (≥ 1 parent born outside Nordics). Main vitamin D sources for 18mo were vitamin D drops and fortified foods: dairy, porridge and cereal drinks; and for 4yo, fortified dairy and fat spreads. Dairy was a large contributor to diet-related GHGEs (18mo: 10%, 4yo: 16%), whereas fortified fat spreads and plant-based dairy alternatives were effective sources of vitamin D, providing the highest vitamin D concentrations per kg CO₂ eq. Conclusions: A high proportion of young children in Sweden are vitamin D sufficient, with dietary vitamin D intake, vitamin D drops, and blood sampling season being major determinants. Fortified dairy is an important dietary source of vitamin D, but a shift to fortified plant-based alternatives would reduce diet-related climate impact and should be explored in future research.

A limited intake of free and added sugars is recommended due to potential associations with adverse health effects and nutrient inadequacy. However, the impact of free and added sugars intakes on dietary intake is unknown in Swedish adolescents. This study investigated associations of free and added sugars intakes with nutrient and food consumption. Data were derived from the Riksmaten Adolescents 2016–2017 cross-sectional survey, including a nationally representative sample of 3099 adolescents, aged around 12, 15 and 18 years, which provided two 24-h recalls. Median nutrient and food group intakes were compared across sugars intake quintiles, with adjustments for sex, school year and energy misreporting. Inverse associations were observed for almost all micronutrients, dietary fibre, essential fats and food groups commonly included in a healthy diet (e.g. vegetables, fruit, dairy products, meat, fish). However, positive associations between free sugars and vitamin C intake were observed, with fruit juice influencing intake trends. Total energy intake was not positively associated with free or added sugars intakes. Higher intakes of free and added sugars (> 12·9 and > 11·3 % of total energy intake) significantly reduced the likelihood of meeting nutrient reference values. However, for critical nutrients within the adolescent diet (vitamin D, Se, dietary fibre and polyunsaturated fats), lower odds of meeting reference values were observed even at lower intakes of free and added sugars. To conclude, with increasing sugars intake, Swedish adolescents appear to displace nutrient-dense foods with sugars-rich foods, emphasising differences in dietary patterns between those with lower v . higher free and added sugars intake.

Adolescence is a critical life stage characterised by rapid development and openness to change. Habits formed during adolescence tend to progress into adulthood, making adolescents a key target group for interventions promoting long-term sustainable dietary patterns. This study quantified the environmental impact of Swedish adolescents’ diets using eight indicators: carbon footprint, cropland use, new nitrogen (N) and new phosphorous (P) inputs, blue water use, pesticides use, biodiversity impact, and ammonia emissions. The national dietary survey Riksmaten Adolescents 2016–17 (n = 3099 adolescents, aged 11–12; 14–15; 17–18 years) was used in the analyses. Impacts were compared with per capita global planetary boundaries for the food system for six indicators and described by sex and age-group for all indicators. The carbon footprint, N and P inputs, and biodiversity impacts substantially exceeded planetary boundaries, even in the quartiles with the lowest impacts. Cropland use was slightly above, whereas blue water remained below. All environmental indicators were higher in males than in females, with the highest impacts observed in the oldest males. When standardizing for energy intake, indicators with the highest contribution from red meat and dairy (carbon footprint, cropland use, N input, ammonia emissions) and P input remained higher in males, whereas those dominated by plant-based foods and discretionary foods (blue water, pesticides) were higher in females. Biodiversity impact did not differ by sex. In the oldest female group beverages contributed to almost 40% of the biodiversity impact. This study shows notable differences in environmental impact by age and sex. The results highlight the importance of including multiple environmental indicators to capture diverse impacts of food consumption. Furthermore, they inform policies aiming at promoting sustainable dietary patterns.

Timing of food intake seems to impact metabolism and circadian rhythms, and eating in synchronisation with the rhythms has been suggested to be favourable for health. This study aims to evaluate temporal meal patterns in the Swedish population and explore differences between population groups. Further, to investigate whether temporal meal patterns are associated with energy and nutrient intake, data were sourced from two national dietary surveys Riksmaten Adolescents 2016–2017 and Riksmaten Adults 2010–2011, with a total of 4763 participants. Food intake and temporal meal patterns were measured with 3- to 4-day food diaries and/or 24-hour recalls. The average meal frequency was 4·2 eating occasions (sd 0·9) per day for adolescents with an eating window of 11·9 h (sd 1·7). For adults, it was 4·6 (sd 1·1) eating occasions and an eating window of 12·0 h (sd 1·9) Meal frequency was positively associated with energy intake in both adolescents (r = 0·47) and adults (r = 0·51). Meal frequency was higher with age, and adolescents skipped breakfast more often, and had a later energy distribution than adults. A higher eating frequency and eating breakfast are associated with a higher absolute intake of whole grains, as well as Vitamin D and folate. A higher eating frequency makes it more likely to reach nutrient requirements. However, a higher eating frequency was also associated with a higher intake of free sugars. The findings can serve as reference data for temporal meal patterns in the Swedish context and also show differences within a population, which can be valuable insights for public health nutrition.

Purpose: The risk of inadequate micronutrient intake is a concern of low-climate impact diets. This study analyzes the prevalence of iron deficiency (ID) among adolescents with varying dietary climate impact, with special reference to different types and dietary sources of iron. Methods: Data on dietary intake (n = 3099) and plasma ferritin (n = 1030) were from Riksmaten Adolescents 2016–2017 survey of Swedish girls and boys aged 11–18 years. Dietary climate impact was estimated with life cycle assessment data. Linear and logistic regression models assessed associations between dietary climate impact, intakes of iron and food groups, and ID. Results: Higher total iron and heme, but not non-heme, iron intake, was linearly associated with higher dietary climate impact. Compared to girls, boys had higher climate impact and low prevalence of ID. Girls in the highest climate impact quartile had 56% lower odds of ID (OR 0.44, 95% CI 0.24–0.81) compared to the lowest quartile, whereas no association was found in boys. Lower intake of red meat and heme iron was associated with ID in girls, while higher intake of dairy was associated with ID in boys. Menstruating girls and adolescents born outside of Sweden were identified risk groups for ID. Conclusions: Girls with a more climate-friendly diet and lower intake of red meat/heme iron may be at higher risk of ID compared to girls with higher dietary climate impact. These results highlight the importance of considering risk groups of ID, such as menstruating girls, in the transition to more plant-based diets with lower climate impact.

Purpose: Swedish adolescents’ free and added sugars intake exceeds recommended levels. This poses potential health problems; however, little is known about dietary sources within the Swedish population. This study investigated dietary sources of sugars among Swedish adolescents, as well as timing and location of free sugars intake. Methods: A nationally representative sample of 3099 adolescents in school years 5, 8 and 11 (ages around 12, 15 and 18) was derived from the Riksmaten Adolescents 2016-17 cross-sectional survey. Dietary intake was self-reported over two non-consecutive days of retrospective registration. Various food categories’ contribution to sugars intake were evaluated in relative and absolute terms. To analyse differences between subsamples in consumption, non-parametric tests and logistic regression analyses were performed. Results: Sugar sweetened beverages (SSBs) were the biggest source of free (30%) and added sugars (34%) within the population, contributing with 4.4% of total energy intake among consumers. SSBs were particularly consumed by boys, adolescents to parents with lower education levels, and those residing in smaller cities/rural areas. Other food categories contributing substantially to free sugars intake were sweets and chocolates (20%), sweet bakery products and desserts (11%), fruit juices (11%), and sweetened dairy products (9%). Intakes of free sugars were higher during weekends, mostly consumed outside of main meals, predominantly within the home environment. Conclusion: The majority of free and added sugars consumed by Swedish adolescents comes from nutrient-poor food sources. SSB intake is highly associated with free and added sugars intake and is the primary source of sugars in the adolescent diet.

Since lack of culture-specific foods in dietary assessment methods may bias reported dietary intake, we identified foods and dishes consumed by residents not born in Sweden and describe consequences for reported foods and nutrient intake using a culturally adapted dietary assessment method. Design consisted of cross-sectional data collection using (semi-)qualitative methods of dietary assessment (and national diet survey instrument RiksmatenFlex) with subsequent longitudinal data collection using quantitative methods for method comparison (December 2020–January 2023). Three community-based research groups were recruited that consisted of mothers born in Sweden, Syria/Iraq, and Somalia, with a median age of 34, 37, and 36 years, respectively. Women born in Syria/Iraq and Somalia who had lived in Sweden for approximately 10 years, reported 78 foods to be added to RiksmatenFlex. In a subsequent study phase, 69% of these foods were reported by around 90% of the ethnic minority groups and contributed to 17% of their reported energy intake. However, differences between the three study groups in median self-reported energy intake remained (Sweden 7.19 MJ, Syria/Iraq 5.54 MJ, and Somalia 5.69 MJ). The groups also showed differences in relative energy contribution from fats and carbohydrates, as well as differences in energy intake from food groups such as bread and sweet snacks. We conclude that a dietary assessment instrument containing culture-specific foods could not resolve group differences in reported energy intake, although these foods provided content validity and contributed 17% of energy intake. The dietary habits collected in this study serve to develop new dietary assessment instruments.

Early puberty has been found to be associated with adverse health outcomes such as metabolic and cardiovascular diseases and hormone-dependent cancers. The decrease in age at menarche observed during the past decades has been linked to an increased exposure to endocrine-disrupting compounds (EDCs). Evidence for the association between PFAS and phthalate exposure and menarche onset, however, is inconsistent. We studied the association between PFAS and phthalate/DINCH exposure and age at menarche using data of 514 teenagers (12 to 18 years) from four aligned studies of the Human Biomonitoring for Europe initiative (HBM4EU): Riksmaten Adolescents 2016–2017 (Sweden), PCB cohort (follow-up; Slovakia), GerES V-sub (Germany), and FLEHS IV (Belgium). PFAS concentrations were measured in blood, and phthalate/DINCH concentrations in urine. We assessed the role of each individual pollutant within the context of the others, by using different multi-pollutant approaches, adjusting for age, age- and sex-standardized body mass index z-score and household educational level. Exposure to di(2-ethylhexyl) phthalate (DEHP), especially mono(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), was associated with an earlier age at menarche, with estimates per interquartile fold change in 5OH-MEHP ranging from −0.34 to −0.12 years in the different models. Findings from this study indicated associations between age at menarche and some specific EDCs at concentrations detected in the general European population, but due to the study design (menarche onset preceded the chemical measurements), caution is needed in the interpretation of causality.

Human biomonitoring has become a pivotal tool for supporting chemicals’ policies. It provides information on real-life human exposures and is increasingly used to prioritize chemicals of health concern and to evaluate the success of chemical policies. Europe has launched the ambitious REACH program in 2007 to improve the protection of human health and the environment. In October 2020 the EU commission published its new chemicals strategy for sustainability towards a toxic-free environment. The European Parliament called upon the commission to collect human biomonitoring data to support chemical’s risk assessment and risk management. This manuscript describes the organization of the first HBM4EU-aligned studies that obtain comparable human biomonitoring (HBM) data of European citizens to monitor their internal exposure to environmental chemicals. The HBM4EU-aligned studies build on existing HBM capacity in Europe by aligning national or regional HBM studies. The HBM4EU-aligned studies focus on three age groups: children, teenagers, and adults. The participants are recruited between 2014 and 2021 in 11 to 12 primary sampling units that are geographically distributed across Europe. Urine samples are collected in all age groups, and blood samples are collected in children and teenagers. Auxiliary information on socio-demographics, lifestyle, health status, environment, and diet is collected using questionnaires. In total, biological samples from 3137 children aged 6–12 years are collected for the analysis of biomarkers for phthalates, HEXAMOLL^® DINCH, and flame retardants. Samples from 2950 teenagers aged 12–18 years are collected for the analysis of biomarkers for phthalates, Hexamoll^® DINCH, and per- and polyfluoroalkyl substances (PFASs), and samples from 3522 adults aged 20–39 years are collected for the analysis of cadmium, bisphenols, and metabolites of polyaromatic hydrocarbons (PAHs). The children’s group consists of 50.4% boys and 49.5% girls, of which 44.1% live in cities, 29.0% live in towns/suburbs, and 26.8% live in rural areas. The teenagers’ group includes 50.6% girls and 49.4% boys, with 37.7% of residents in cities, 31.2% in towns/suburbs, and 30.2% in rural areas. The adult group consists of 52.6% women and 47.4% men, 71.9% live in cities, 14.2% in towns/suburbs, and only 13.4% live in rural areas. The study population approaches the characteristics of the general European population based on age-matched EUROSTAT EU-28, 2017 data; however, individuals who obtained no to lower educational level (ISCED 0–2) are underrepresented. The data on internal human exposure to priority chemicals from this unique cohort will provide a baseline for Europe’s strategy towards a non-toxic environment and challenges and recommendations to improve the sampling frame for future EU-wide HBM surveys are discussed.