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.

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.

Dietary survey ‘Riksmaten Adolescents 2016–2017’ in schools across Sweden.

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

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.

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

This study examines secular changes in diet-related greenhouse gas emissions (GHGE) in younger and older Swedish adults, since the turn of this century.

Two cross-sectional health examination surveys were conducted in 2001–2004 (T1) and 2014–2018 (T2). At both times, an eighty-six-item FFQ was embedded in the survey. From the food frequencies and age-standardised portion sizes, GHGE estimates (kg CO2e/year) were calculated. GHGE was modelled as a function of time period and covariates, for five distinct age groups.

The municipality of Gothenburg, in western Sweden.

Women and men aged 25–34, 35–44, 45–54, 55–64 and 65–75 years were randomly selected from the population registry and recruited for examinations. After exclusion of participants with incomplete dietary data, the analytic sample consisted of 2569 individuals at T1 and 2119 at T2.

Lower dietary GHGE scores were observed at T2 compared with T1, in each age group, adjusting for sex, BMI and education. The largest differences in GHGE were observed in the youngest age group (approximately 30 % reduction). Decreasing trends in GHGE from animal-based foods were observed at all ages and were accompanied by smaller increases from plant-based sources in younger groups only. At all ages, GHGE from discretionary foods decreased, and prevalence of overweight remained stable.

Optimal dietary trends should support both human health and planetary health. Our results suggest that Swedish adults have moved in this direction, e.g. through less intake of red meat products and stable weight status.

Consumption of fruits and vegetables (F&V) among adolescents falls below recommendations in many Western countries. The impact of social and emotional aspects of family life on adolescent dietary behaviour may contribute to this, yet remains under-investigated. The present study examines the association between adolescents’ perceptions of emotional home atmosphere (EHA) and their F&V consumption frequency.

An FFQ was used to assess F&V consumption frequency. EHA was assessed by an eight-item measure with three subscales: perceived home warmth, strictness and relational tension. EHA subscales were used as binary variables: a score equal to or above the median value was considered as a higher perception, while a score below the median was considered as a lower perception of the EHA in question. Country differences in meeting the European 5-a-day recommendations were described. Further, the association between EHA and F&V consumption frequency was investigated using multiple linear regression.

Regional examination centres in eight European countries.

Adolescents (n 3196) aged 12–18 years.

The mean F&V consumption frequency was 3·27 (sd 2·84) times/d. Only 16·1 % of boys and 18 % of girls in our study sample met the recommendation of five F&V daily. After controlling for age, sex, education level of the parents and country of origin, perceived home warmth was associated with a 16 (95 % CI 9, 22) % higher F&V consumption frequency (P < 0·001).

F&V consumption frequency was suboptimal in the survey areas. Interventions targeting perceived warmth as a component of EHA could potentially have a positive effect on adolescents’ dietary behaviour.

The present study investigated the association between sugar and fat intake in childhood in relation to alcohol use in adolescence. We hypothesized that early exposure to diets high in fat and sugar may affect ingestive behaviours later in life, including alcohol use.

Children from the European IDEFICS/I.Family cohort study were examined at ages 5–9 years and followed up at ages 11–16 years. FFQ were completed by parents on behalf of children, and later by adolescents themselves. Complete data were available in 2263 participants. Children’s propensities to consume foods high in fat and sugar were calculated and dichotomized at median values. Adolescents’ use of alcohol was classified as at least weekly v. less frequent use. Log-binomial regression linked sugar and fat consumption in childhood to risk of alcohol use in adolescence, adjusted for relevant covariates.

Five per cent of adolescents reported weekly alcohol consumption. Children with high propensity to consume sugar and fat were at greater risk of later alcohol use, compared with children with low fat and low sugar propensity (relative risk=2·46; 95 % CI 1·47, 4·12), independent of age, sex and survey country. The association was not explained by parental income and education, strict parenting style or child's health-related quality of life and was only partly mediated by sustained consumption of sugar and fat into adolescence.

Frequent consumption of foods high in fat and sugar in childhood predicted regular use of alcohol in adolescence.

Children may influence household spending through ‘pester power’. The present study examined pestering through parent–child food shopping behaviours in relation to children’s diet and weight status.

Cross-sectional and prospective analyses drawn from the IDEFICS study, a cohort study of parents and their children. Children’s height and weight were measured and their recent diets were reported by parental proxy based on the Children’s Eating Habits Questionnaire-FFQ at baseline and 2-year follow-up. Parents also completed questionnaires at both time points about pestering, including whether the child goes grocery shopping with them, asks for items seen on television and is bought requested food items.

Participants were recruited from eight European countries for the IDEFICS study (non-nationally representative sample).

Study participants were children aged 2–9 years at enrolment and their parents. A total of 13 217 parent–child dyads were included at baseline. Two years later, 7820 of the children were re-examined.

Most parents (63 %) at baseline reported ‘sometimes’ acquiescing to their children’s requests to purchase specific foods. Pestering was modestly associated with weight and diet. At baseline, children whose parents ‘often’ complied consumed more high-sugar and high-fat foods. Children who ‘often’ asked for items seen on television were likely to become overweight after 2 years (OR=1·31), whereas ‘never’ asking protected against overweight (OR=0·72).

Pestering was modestly related to diet and weight in cross-sectional, but not longitudinal analyses. Asking for items seen on television had the most robust relationships across child outcomes and over time.

The objective of the present study was to investigate the association between salivary counts of mutans streptococci (MS) and children’s weight status, while considering associated covariates. MS ferments carbohydrates from the diet and contributes to caries by lowering the pH in dental plaque. In adults, high counts of MS in saliva have been associated with overweight, but this has not been shown in children.

Cross-sectional study investigating salivary counts of MS, BMI Z-score, waist circumference, meal frequency, sugar propensity and sleep duration, in children.

West Sweden.

Children (n 271) aged 4–11 years.

Medium–high counts of MS were positively associated with higher BMI Z-score (OR=1·6; 95 % CI 1·1, 2·3). Positive associations were also found between medium–high counts of MS and more frequent meals per day (OR=1·5; 95 % CI 1·1, 2·2), greater percentage of sugar-rich foods consumed (OR=1·1; 95 % CI 1·0, 1·3) and female sex (OR=2·4; 95 % CI 1·1, 5·4). A negative association was found between medium–high counts of MS and longer sleep duration (OR=0·5; 95 % CI 0·3, 1·0).

BMI Z-score was associated with counts of MS. Promoting adequate sleep duration and limiting the intake frequency of sugar-rich foods and beverages could provide multiple benefits in public health interventions aimed at reducing dental caries and childhood overweight.

First, to evaluate the ability of a short dietary questionnaire (SDQ) to estimate energy intake (EI) on group and individual levels compared with total energy expenditure (TEE) measured by the doubly labelled water method. Second, to compare the SDQ's performance in estimating energy, nutrient and food intakes with a sixty-six-item FFQ used in large-scale Swedish epidemiological research.

Cross-sectional.

Umeå, Sweden.

In total, sixty-five non-pregnant women, of whom thirty-one were overweight or obese, and twenty-five pregnant, normal-weight women completed the protocol.

On average, the SDQ captured 78 % and 79 % of absolute TEE in the non-pregnant and pregnant normal-weight women, respectively. Furthermore, the SDQ captured an average of 57 % of TEE in the overweight/obese non-pregnant women. The Spearman correlation of EI and TEE was significant in the overweight and obese women only (ρ = 0·37, 95 % CI 0·02, 0·64). There was no significant difference between the SDQ and the more extensive FFQ in the ability to assess EI when compared with TEE. Intakes of most nutrients and foods were significantly higher when assessed with the SDQ compared with the FFQ.

A new short dietary questionnaire with an alternative design underestimated EI of non-pregnant and pregnant, overweight and obese women on a group level but was able to rank the overweight/obese women according to EI. Furthermore, the short questionnaire captured as much or more of the energy, nutrient and food intakes of non-pregnant normal-weight and overweight/obese women on the group level as a traditional, more extensive FFQ.

To estimate the prevalence of physical activity and sedentary behaviours in European children, and to evaluate the relationship between media availability in personal space and physical activity in relation to total screen time.

Data from the baseline IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cross-sectional survey. Information on hours of television/digital video disk/video viewing and computer/games-console use (weekday and weekend days), media device availability in personal space, sports club membership, hours of active organized play and commuting (to and from school) were assessed via a self-reported parental questionnaire. Total screen time was defined as the sum of daily media use and subsequently dichotomized into meeting or not meeting the guidelines of the American Academy of Pediatrics.

Eight survey centres (Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary and Spain).

Children (n 15 330; 51 % males) aged 2–10 years.

Percentage of children engaged in total screen time for >2 h/d was higher on weekend days (52 % v. 20 % on weekdays) and in the older group (71 % in males; 57 % in females), varying by country. Children with a television set in their bedroom were more likely not to meet the screen time recommendations (OR = 1·54; 95 % CI 1·60, 1·74).

Approximately a third of the children failed to meet current screen time recommendations. Availability of a television set in personal space increased the risk of excess total screen time. This information could be used to identify potential targets for public health promotion actions of young population groups.

To analyse the association between family structure and adiposity in children.

Cross-sectional and longitudinal analysis of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study cohort.

Primary schools and kindergartens.

Children (n 12 350; aged 7·9 (sd 1·8) years) for the cross-sectional analysis and children (n 5236; at baseline: normal weight, aged 5·9 (sd 1·8) years) for the longitudinal study underwent anthropometry. Family structure was analysed as (i) number and type of cohabiting adults and (ii) number of siblings.

In the cross-sectional analysis, after controlling for covariates, children living with grandparents had significantly higher BMI Z-score than those living with both parents (0·63; 95 % CI 0·33, 0·92 v. 0·19; 95 % CI 0·17, 0·22; P < 0·01); in addition, the higher the number of siblings, the lower the BMI Z-score (only child = 0·31; 95 % CI 0·24, 0·38; 1 sibling = 0·19; 95 % CI 0·16, 0·23; 2 siblings = 0·15; 95 % CI 0·09, 0·20; >2 siblings = 0·07, 95 % CI 0·04, 0·19; P < 0·001). Over the 2-year follow-up, differences in weight gain were observed across family-structure categories. Further, the risk of incidence of overweight/obesity was significantly lower the higher the number of siblings living in the household (v. only child: 1 sibling = 0·74, 95 % CI 0·57, 0·96; 2 siblings = 0·63, 95 % CI 0·45, 0·88; >2 siblings = 0·40, 95 % CI 0·21, 0·77), independently of confounders.

The study suggests that an independent association between family structure and childhood obesity exists.

We investigated the association between full breast-feeding up to 6 months as well as partial breast-feeding after 6 months and maternal weight retention at 6, 18 and 36 months after delivery in the Norwegian Mother and Child Cohort Study (MoBa), conducted by the Norwegian Institute of Public Health.

Cohort study. Information on exposure and outcome was collected by questionnaire.

Norway.

Women at 6 months (n 49 676), 18 months (n 27 187) and 36 months (n 17 343) postpartum.

Longer duration of full breast-feeding as well as partial breast-feeding was significantly related to lower weight retention at 6 months. At 18 months full breast-feeding (0–6 months) and partial breast-feeding for 12–18 months were significantly related to lower weight retention. At 36 months only full breast-feeding (0–6 months) was significantly related to lower weight retention. For each additional month of full breast-feeding, maternal weight was lowered by 0·50 kg/month at 6 months, 0·10 kg/month at 18 months and 0·14 kg/month at 36 months (adjusted for pre-pregnant BMI, pregnancy weight gain, age and parity). Partial breast-feeding resulted in 0·25 kg/month lower maternal weight at 6 months. Interactions were found between household income and full breast-feeding in relation to weight retention at 6, 18 and 36 months, indicating most benefit among women with low income.

The present study supports the hypothesis that full breast-feeding contributes to lower postpartum weight retention and shows that the effect is maintained for as long as 3 years postpartum.

To compare, specifically by age group, proxy-reported food group estimates obtained from the food frequency section of the Children's Eating Habits questionnaire (CEHQ-FFQ) against the estimates of two non-consecutive 24 h dietary recalls (24-HDR).

Estimates of food group intakes assessed via the forty-three-food-group CEHQ-FFQ were compared with those obtained by a computerized 24-HDR. Agreement on frequencies of intakes (equal to the number of portions per recall period) between the two instruments was examined using crude and de-attenuated Pearson's correlation coefficients, cross-classification analyses, weighted kappa statistics (κw) and Bland–Altman analysis.

Kindergartens/schools from eight European countries participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) Study cross-sectional survey (2007–2008).

Children aged 2–9 years (n 2508, 50·4 % boys).

The CEHQ-FFQ provided higher intake estimates for most of the food groups than the 24-HDR. De-attenuated Pearson correlation coefficients ranged from 0·01 (sweetened fruit) to 0·48 (sweetened milk) in children aged 2–<6 years (mean = 0·25) and from 0·01 (milled cereal) to 0·44 (water) in children aged 6–9 years (mean = 0·23). An average of 32 % and 31 % of food group intakes were assigned to the same quartile in younger and older children, respectively, and classification into extreme opposite quartiles was ≤12 % for all food groups in both age groups. Mean κw was 0·20 for 2–<6-year-olds and 0·17 for 6–9-year-olds.

The strength of association estimates assessed by the CEHQ-FFQ and the 24-HDR varied by food group and by age group. Observed level of agreement and CEHQ-FFQ ability to rank children according to intakes of food groups were considered to be low.

To assess the association between exclusive breast-feeding and childhood overweight.

Cross-sectional data are from the baseline survey of the longitudinal cohort study IDEFICS. Exclusive rather than partial breast-feeding is the focus of the study due to the theoretical relationship between exclusive breast-feeding and development of dietary self-regulation. Children's measured heights and weights were used to calculate weight status, while waist-to-height ratio (WtHR) and skinfold measures were examined as alternative indicators of adiposity and fat patterning.

Examination centres in eight European countries (Italy, Estonia, Cyprus, Belgium, Sweden, Hungary, Germany and Spain).

The analysis included 14 726 children aged 2–9 years for whom early feeding practices were reported by parents in standardized questionnaires.

After controlling for education, income and other potential confounders, breast-feeding exclusively for 4–6 months was protective of overweight (including obesity) when compared with children never exclusively breast-fed (OR = 0·73; 95 % CI 0·63, 0·85) across all measures of overweight. Exclusively breast-feeding for 6 months offered slightly more protection than for 4 and 5 months combined (OR = 0·71; 95 % CI 0·58, 0·85). The associations could not be explained by socio-economic characteristics or maternal overweight.

This multi-country investigation indicated that exclusive breast-feeding for 4–6 months may confer protection against overweight in addition to other known benefits. There was no demonstrated benefit of exclusive breast-feeding for more than 6 months or combination feeding for any duration across all measures of overweight examined.

Dietary patterns capture the overall diet and thereby provide information on how nutrients are consumed in combinations, and have been suggested to be a better method than studying single nutrients. The present study explored the relationship between dietary patterns at baseline and incidence of obesity at 10-year follow-up in women.

A longitudinal study using baseline measurements from 1992–1996, including food intake, medication, heredity, socio-economic status, lifestyle and measured body composition, and follow-up data collected in 2002–2006 including measured body composition.

Data from the Västerbotten Intervention Programme (VIP) in Sweden.

A total of 6545 initially non-obese women aged 30–50 years.

Among women reporting plausible energy intakes, the ‘Fruit and vegetables cluster’ predicted the highest incidence of obesity (OR = 1·76, 95 % CI 1·11, 2·76; P = 0·015) compared with women in the other food pattern groups combined. When adjusting for metabolic factors and BMI at baseline, the risk for obesity in the ‘Fruit and vegetables cluster’ was attenuated to non-significance. In contrast, high intake of fruit per se was associated with a decreased risk of developing obesity (OR = 0·69, 95 % CI 0·51, 0·91; P = 0·010).

Dietary pattern groups identified by cluster analysis are likely to reflect characteristics in addition to diet, including lifestyle, previous and current health status and risk factors for future disease, whereas intake of fruit per se was a stable indicator and less affected by baseline characteristics. These results underscore the need for complementary methods in understanding diet–disease relationships.

To describe the consequences of systematic reporting bias by the obese for diet–disease relationships.

The present report used 24-hour urinary nitrogen and estimates of 24-hour energy expenditure to assess error in diet reporting, and examined the consequence of accounting for this error for associations between dietary fat intake and serum low-density lipoprotein (LDL)-cholesterol.

Sub-study to the Danish MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) project, carried out in 1987–1988.

A random sub-sample of the adult Danish male population (n = 152).

Correcting dietary fat for underreporting error weakened, rather than strengthened, the association between dietary fat intake and LDL-cholesterol by reducing the slope of the regression from β = 3.4, P = 0.02 to β = 2.7, P = 0.04.

This example illustrates that systematic underreporting of dietary fat by high-risk groups such as the obese may produce an overestimated association. These results imply that previous epidemiological studies showing a positive association between percentage of energy from fat and other health outcomes, e.g. cancer and heart disease, may have overestimated the negative effects of a high-fat diet. If we were able to correctly assess dietary fat intake in general populations, recommendations for fat intake may be more liberal than the 30% suggested today. Improved assessment of fat intake in epidemiological studies is necessary for future development of evidence-based recommendations for diet and health.