As global warming intensifies, residents of temperate regions will also face heat waves in the near future. Food habits are one component in addressing the global challenge of climate change. However, water, the most important food for humans, has not been adequately addressed.

For this commentary, on the one hand, publications on the increasing heat stress of children were consulted. On the other hand, publications on the special demands of children’s temperature regulation in hot environments on fluid balance were analysed.

The situation of young children in care facilities on days with heat stress is presented as a scenario. In this way, the effects of climatic changes on fluid balance can be estimated and measures to reduce heat stress and stabilise the fluid balance of children can be developed.

For this analysis, first, infants will be considered in order to identify their specific fluid needs. Second, the possibilities for caregivers to improve fluid intake and train appropriate drinking habits already in infancy will be highlighted.

Climate change should be included in recommendations on hydration for children. The need to adapt drinking habits requires educational approaches to weather and water – starting in early childhood care.

In the face of rapid climate change, countries must act now by protecting, preparing and prioritising the high-risk group of children. Particular focus should be placed on supporting adequate hydration.

The present study aimed to assess the current state of breast-feeding promotion in hospitals and the prevalence of breast-feeding during the first year of life in Germany and to compare the results with a study 20 years earlier.

In the studies on ‘breast-feeding and infant nutrition in Germany’ named ‘SuSe’, a cross-sectional survey in hospitals was combined with a subsequent prospective survey of breast-feeding and infant nutrition during the first year of life (0·5, 2, 4, 6 and 12 months after birth) in mother–infant pairs who were recruited in the hospitals. Written questionnaires and phone calls were used in SuSe I and web-based questionnaires in SuSe II. Breast-feeding promotion and prevalence were evaluated using recommendations from the WHO and the UNICEF.

Two nationwide surveys SuSe I (1997–1998) and SuSe II (2017–2019).

In SuSe I, 177 hospitals and 1717 mother–infant pairs and in SuSe II 109 hospitals and 962 mother–infant pairs were included.

In SuSe II, hospitals implemented seven of the WHO ‘Ten Steps to Successful Breastfeeding’ to a greater extent than the hospitals in SuSe I. More mothers exclusively breastfed for 4 months (57 % v. 33 %) and continued breast-feeding until 6 (78 % v. 48 %) and 12 months (41 % v. 13 %). In both studies, exclusive breast-feeding decreased between 4 and 6 months of age due to the introduction of complementary feeding.

In Germany, breast-feeding habits have come closer to the recommendations over the last 20 years.

Psychosocial stressors deriving from socioeconomic disadvantages in adolescents can result in higher metabolic syndrome (MetS) risk. We aimed to examine whether socioeconomic disadvantages were associated with MetS independent of lifestyle and whether there was a dose response relationship between the number of cumulated socioeconomic disadvantages and the risk of MetS.

The present study included 1,037 European adolescents (aged 12.5–17.5) of the 3,528 total HELENA participants. Sociodemographic variables and lifestyle were assessed through self-reported questionnaires. Disadvantaged groups included adolescents with low educated parents, low family affluence, migrant origin, unemployed parents, and from non-traditional families. MetS score was calculated as the sum of sex- and age-specific z-scores of waist circumference, HOMA-IR index, mean of z-scores of diastolic and systolic blood pressure and mean of z-score of HDL-C multiplied by -1 and z-score of TG. A higher score indicates poor metabolic health. Linear mixed-effects models were used to study the association between social disadvantages and MetS risk score. Models were adjusted for sex, age, pubertal status (Tanner stage) and lifestyle (diet quality, physical activity, alcohol consumption and smoking status).

Adolescents with low educated mothers showed a higher MetS score (0.54 [0.09–0.98]; β [99% confidence interval]) compared to high-educated mothers. Adolescents who accumulated more than three disadvantages (0.69 [0.08–1.31]) or with missing information on disadvantages (0.72 [0.04–1.40]) had a higher MetS risk compared to non-socioeconomically disadvantaged groups. Stronger associations between socioeconomic disadvantages and MetS were found in male in comparison with female adolescents.

Out of the studied socioeconomic disadvantages, maternal education is the most important determinant of adolescent's MetS risk independently of sex, age, Tanner stage, smoking status, alcohol consumption, diet quality and physical activity. Social vulnerabilities (migrant background, unemployment status and belonging to a non-traditional family) were not associated with a higher MetS risk in European adolescents. However, we found a dose-response relationship between the number of factors related to social disadvantage and adolescents’ MetS risk with adolescents accumulating three or more socioeconomic disadvantages showing the highest risk. Stronger associations between socioeconomic disadvantages and MetS were found in male compared to female adolescents. Policy makers should focus on low educated families to tackle health disparities.

To develop a scale to assess health motivation influencing food choices and to explore its performance in the associations with food intakes and nutritional biomarkers.

Psychometric study using cross-sectional self-report questionnaires and nutritional biomarkers.

Multi-centre investigation conducted in ten European cities.

2954 adolescents who were included in the HELENA study and completed the Food Choices and Preferences (FCP) questionnaire.

Nineteen out of 124 items of the FCP questionnaire were in the same dimension. Sixteen presented adequate parameters for the Scale of evaluatiOn of Food choIcEs (SOFIE). The scores were positively associated with the intakes of cereals, dairy products, meats and eggs, and fish, as well as with blood concentrations of vitamin C, β-carotene, n-3 fatty acids, cobalamin, holo-transcobalamin and folate; scores were negatively associated with the intake of alcohol.

SOFIE can improve the assessment of motivation influencing food choices based on items with the best performance and is proposed as a new measure to health-related studies.

To investigate whether adherence to the adapted Mediterranean Diet Score for Adolescents (MDS_A) and the adapted Mediterranean Diet Quality Index for Adolescents (KIDMED_A) is associated with better food/nutrient intakes and nutritional biomarkers.

The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study is a cross-sectional study aiming to obtain comparable data on a variety of nutritional and health-related parameters in European adolescents aged 12·5–17·5 years.

Nine European countries.

European adolescents (n 2330) recruited to the HELENA study. Dietary intake was obtained with 24 h dietary recalls, an FFQ and a Food Choices and Preferences questionnaire. MDS_A was calculated as a categorical variable using cut-offs (MDS_A), as a continuous variable (zMDS_A) and with energy adjustments (zEnMDS_A). The KIDMED_A score was also calculated.

Multilevel linear regression analysis showed positive associations for zMDS_A and KIDMED_A with serum levels of vitamin D, vitamin C, plasma folate, holo-transcobalamin, β-carotene and n-3 fatty acids, while negative associations were observed with trans-fatty acid serum levels. For categorical indices, blood biomarkers showed few significant results. zMDS_A and KIDMED_A showed positive associations with vegetables and fruits intake, and negative associations with energy-dense and low-nutritious foods. zMDS_A and KIDMED_A were positively associated with all macronutrients, vitamins and minerals (all P < 0·0001), except with monosaccharides and PUFA for KIDMED_A and cholesterol for both indices (P < 0·05).

zMDS_A and KIDMED_A have shown the strongest associations with the dietary indicators and biomarkers that have been associated with the Mediterranean diet before, and are therefore considered the most appropriate and valid Mediterranean diet scores for European adolescents.

To analyse the Nutritional Knowledge Test (NKT) using Item Response Theory (ITR) analysis and to assess the construct validity of the Nutritional Knowledge Scale (NKTS) and its associations with adolescent food group consumption and nutritional biomarkers.

Cross-sectional study.

Multicentre investigation conducted in ten European cities.

Adolescents aged 12·5–17·5 years (n 3215) who completed over 75 % of the NKT.

Factor analysis indicated that the NKT can be analysed with a one-dimensional model. Eleven out of twenty-three items from the NKT presented adequate parameters and were selected to be included in the NKTS. Nutrition knowledge was positively associated with consumption of fruits, cereals, dairy products, pulses, meat and eggs, and fish, as well as with blood concentrations of vitamin C, β-carotene, n-3 fatty acids, holo-transcobalamin, cobalamin and folate; nutrition knowledge was negatively associated with intake of olives and avocado, alcohol and savoury snacks.

The NKTS assessed nutritional knowledge adequately and it is proposed as a new tool to investigate this subject in future studies.

To examine the associations between adolescents’ diet quality and their perceived relatives’ and peers’ diet engagement and encouragement.

Cross-sectional study performed in European countries. Diet quality was scored using the Diet Quality Index for Adolescents (DQI-A) based on four components: quality, diversity, balance and meal frequency. Perceived diet quality engagement and perceived encouragement of the relatives/peers were assessed using the questions ‘How healthy is each of the following persons’ diet?’ and ‘How often does each of the following persons encourage you to eat a healthy diet?’

Vienna, Ghent, Lille, Athens, Heraklion, Pecs, Rome, Dortmund, Zaragoza and Stockholm.

Healthy adolescents (n 2943).

The perceived engagement level of the mother, father and sister was each positively associated with the DQI-A (P<0·05). A positive association was found for the perceived engagement level of siblings, father and mother with all specific components (P<0·05). DQI-A was negatively associated with the perceived encouragement level from a best friend and positively associated with the encouragement level of the mother and father (P<0·05). Diversity, balance and quality components were positively associated with the perceived encouragement level from the mother and father (P<0·05), whereas the best friend’s perceived encouragement was negatively associated with the meal frequency component (P<0·01).

These findings highlight the role of social engagement and encouragement of relatives and peers in adolescents’ diet quality. Intervention or promotion programmes aimed at enhancing diet quality in adolescents should target both family and peers.

To investigate dietary sources of Ca and vitamin D (VitD) intakes, and the associated sociodemographic and lifestyle factors, among European adolescents.

Linear regression mixed models were used to examine sex-specific associations of Ca and VitD intakes with parental education, family affluence (FAS), physical activity and television (TV) watching while controlling for age, Tanner stage, energy intake and diet quality.

The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA)Cross-Sectional Study.

Adolescents aged 12·5–17·5 years (n 1804).

Milk and cheese were the main sources of Ca (23 and 19 % contribution to overall Ca intake, respectively). Fish products were the main VitD source (30 % contribution to overall VitD intake). Ca intake was positively associated with maternal education (β=56·41; 95 % CI 1·98, 110·82) and negatively associated with TV viewing in boys (β=–0·43; 95 % CI −0·79, −0·07); however, the significance of these associations disappeared when adjusting for diet quality. In girls, Ca intake was positively associated with mother’s (β=73·08; 95 % CI 34·41, 111·74) and father’s education (β=43·29; 95 % CI 5·44, 81·14) and FAS (β=37·45; 95 % CI 2·25, 72·65). This association between Ca intake and mother’s education remained significant after further adjustment for diet quality (β=41·66; 95 % CI 0·94, 82·38). Girls with high-educated mothers had higher Ca intake.

Low-educated families with poor diet quality may be targeted when strategizing health promotion programmes to enhance dietary Ca.

The present study aimed to examine the association between different breakfast consumption patterns and vitamin intakes and blood vitamin concentrations in European adolescents.

Breakfast consumption was assessed by a questionnaire. Vitamin intake was calculated from two 24 h recalls. Blood vitamin and total homocysteine (tHcy) concentrations were analysed from fasting blood samples.

The European Commission-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.

Participants were 1058 (52·8 % females) European adolescents (aged 12·5–17·5 years) from ten cities.

Lower vitamin D and vitamin C concentrations were observed in male and female breakfast skippers than in consumers (P<0·05). Female breakfast consumers presented higher holo-transcobalamin and lower tHcy (P<0·05), while males had higher cobalamin concentrations, compared with skippers (P<0·05). Higher vitamin D and total folate intakes were observed in adolescents who consumed breakfast compared with skippers (P<0·05). Likewise, female consumers had higher intakes of vitamin B6 and vitamin E than occasional consumers (P<0·05).

Regular breakfast consumption is associated with higher blood vitamin D and cobalamin concentrations in males and with higher vitamin D and holo-transcobalamin and lower tHcy concentrations in females. Moreover, breakfast consumption is associated with high intakes of vitamin D and total folate in both sexes, and with high intakes of vitamin B6 and vitamin E in females.

An adequate nutritional intake in childhood and adolescence is crucial for growth and the prevention of youth and adult obesity and nutrition-related morbidities. Improving nutrient intake in children and adolescents is of public health importance. The purpose of the present study was to describe and evaluate the nutrient intake in a European sample using the D-A-CH nutrient intake recommendations and the Nutritional Quality Index (NQI).

The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study is a cross-sectional study, the main objective of which is to obtain comparable data on a variety of nutritional and health-related parameters in adolescents aged 12·5–17·5 years.

Eight cities in Europe.

The initial sample consisted of 3528 European adolescents. Among these, 1590 adolescents (54 % female) had sufficient and plausible dietary data on energy and nutrient intakes from two 24 h recalls using the HELENA-DIAT software.

The intakes of most macronutrients, vitamins and minerals were in line with the D-A-CH recommendations. While the intakes of SFA and salt were too high, the intake of PUFA was too low. Furthermore, the intakes of vitamin D, folate, iodine and F were less than about 55 % of the recommendations. The median NQI was about 71 (of a maximum of 100).

The intakes of most nutrients were adequate. However, further studies using suitable criteria to assess nutrient status are needed. Public health initiatives should educate children and adolescents regarding balanced food choices.

The present study aimed to evaluate the relationship between the consumption of selected food groups and insulin resistance, with an emphasis on sugar-sweetened beverages (SSB).

The present research is a large multicentre European study in adolescents, the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study).

Homeostasis model assessment–insulin resistance index (HOMA-IR) was calculated. Several anthropometric and lifestyle characteristics were recorded. Dietary assessment was conducted by using a short FFQ.

The participants were a subset of the original sample (n 546) with complete data on glucose, insulin and FFQ. All participants were recruited at schools.

Median (25th, 75th percentile) HOMA-IR was 0·62 (0·44, 0·87). Mean HOMA-IR was significantly higher among adolescents consuming brown bread ≤1 time/week than among those consuming 2–6 times/week (P = 0·011). Mean values of HOMA-IR were also higher in adolescents consuming SSB >5 times/week compared with those consuming less frequently, although a statistically significant difference was detected between those consuming SSB 5–6 times/week and 2–4 times/week (P = 0·049). Multiple linear regression analysis showed that only the frequency of SSB consumption was significantly associated with HOMA-IR after controlling for potential confounders. In particular, it was found that HOMA-IR levels were higher among adolescents consuming SSB 5–6 times/week and ≥1 time/d compared with those consuming ≤1 time/week by 0·281 and 0·191 units, respectively (P = 0·009 and 0·046, respectively).

The present study revealed that daily consumption of SSB was related with increased HOMA-IR in adolescents.

To determine the relative validity of a 3 d estimated food record (EFR) used to assess energy and nutrient intakes in toddlers, using a 3 d weighed food record (WDR) as the reference method.

Parents reported the food and beverage intakes of their children using an EFR concurrently with a WDR over three consecutive days. Estimation of mean differences, Spearman correlation coefficients, cross-classifications and Bland–Altman plots were used to assess the agreement between the intakes of energy and fourteen nutrients obtained from the EFR and the WDR.

Data obtained from a representative sample of infants or toddlers in Germany.

Sixty-seven toddlers aged 10–36 months who had completed an EFR for a 3 d recording period that corresponded to the WDR were included in the present analysis.

Energy and nutrient intakes did not differ between the EFR and the WDR, except for linoleic acid and retinol. For all dietary intakes, Spearman rank correlation coefficients between the EFR and the WDR ranged from 0·35 to 0·80 (P ≤ 0·004). The proportion of participants correctly classified into quartiles ranged from 75 % for ascorbic acid intake to 96 % for Fe intake, and the percentage of misclassification was 9 % or less. The weighed κ values ranking the participants ranged from 0·23 for ascorbic acid intake to 0·59 for Fe intake. The Bland–Altman plots indicated a good agreement for all dietary intakes estimated from the EFR.

Our study suggests that this EFR is a valid assessment instrument for estimating the energy and nutrient intakes among toddlers at the group level.

To describe breakfast habits at food group level in European adolescents and to investigate the associations between these habits and sociodemographic factors.

Cross-sectional study.

Secondary schools from nine European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study. Breakfast habits were assessed twice using a computer-based 24 h dietary recall. Adolescents who consumed breakfast on at least one recall day were classified as ‘breakfast consumers’ and adolescents who did not have anything for breakfast on either of the two recall days were considered ‘breakfast skippers’. A ‘breakfast quality index’ to describe breakfast quality was created based on the consumption or non-consumption of cereals/cereal products, dairy products and fruits/vegetables. The sociodemographic factors studied were sex, age, region of Europe, maternal and paternal education, family structure and family affluence.

Adolescents (n 2672, 53 % girls) aged 12–17 years.

The majority of the adolescents reported a breakfast that scored poorly on the breakfast quality index. Older adolescents, adolescents from the southern part of Europe and adolescents from families with low socio-economic status were more likely to consume a low-quality breakfast.

The study highlights the need to promote the consumption of a high-quality breakfast among adolescents, particularly in older adolescents, adolescents from southern Europe and adolescents from families with low socio-economic status, in order to improve public health.