The present study was performed to investigate whether breast-feeding is associated with early pubertal development among children 7–9 years old in Korea.

Children were divided into those who did and did not receive breast-feeding for 6 months or longer in accordance with the recommendations of the WHO. Pubertal status was determined by clinical examination using Tanner staging.

Prospective observational study.

We conducted a follow-up study of children aged 7–9 years in 2011 who had taken part in the Ewha Birth & Growth Cohort study.

Fifty (22·8 %) of the total of 219 children were in early puberty, with the proportion being slightly higher for girls (24·1 %) than boys (21·4 %). Children who had entered early puberty were taller, weighed more and had a higher concentration of insulin-like growth factor 1. Moreover, the change in weight Z-score from birth to follow-up was significantly lower in children who were breast-fed than in those who were not (weight Z-score change: 0·32 (sd 1·59) v. 0·77 (sd 1·61), respectively, P=0·04). Comparison of breast-feeding by puberty status indicated a preventive association with early puberty in children who were breast-fed for 6 months or longer (OR=0·37; 95 % CI 0·18, 0·74). This association remained significant after adjustment for relevant covariates.

These results demonstrate a beneficial association between breast-feeding and early pubertal development, especially in those breast-fed for 6 months or longer. The study suggests that interventions would need to start early in life to prevent early pubertal development.

To examine demographic and behavioural correlates of unhealthy snack-food consumption among Australian secondary-school students and the association between their perceptions of availability, convenience and intake with consumption.

Cross-sectional survey of students’ eating, physical activity and sedentary behaviours using validated instruments administered via an online questionnaire.

Australian secondary schools across all states/territories.

Secondary-school students aged 12–17 years participating in the 2009–10 National Secondary Students’ Diet and Activity (NaSSDA) survey (n 12 188).

Approximately one in five students (21 %) reported consuming unhealthy snack foods ≥14 times/week (‘frequent snackers’). After adjusting for all covariates, older students and those with a BMI of ≥25 kg/m2 were less likely to be frequent snackers, while students who reported high fast-food and high sugar-sweetened beverage consumption and those who watched television for >2 h/d were more likely to snack frequently. Furthermore, after adjusting for all covariates and demographic factors, students who agreed that snack foods are usually available at home, convenient to buy and that they eat too many snack foods were more likely to be snacking frequently. Conversely, students who agreed that fruit is a convenient snack were less likely to be frequent snackers.

Frequent unhealthy snack-food consumption appears to cluster with other poor health behaviours. Perceptions of availability and convenience are factors most readily amenable to change, and findings suggest interventions should focus on decreasing the availability of unhealthy snack foods in the home and promoting healthier options such as fruit as convenient snacks.

To assess how breast-feeding and dietary diversity relate to infant length-for-age Z-score (LAZ) and weight-for-age Z-score (WAZ).

Breast-feeding, dietary and anthropometric data from the Cebu Longitudinal Health and Nutrition Survey were analysed using sex-stratified fixed-effects longitudinal regression models. A dietary diversity score (DDS) based on seven food groups was classified as low (<4) or high (≥4). The complementary feeding patterns were: (i) non-breast-fed with low DDS (referent); (ii) breast-fed with low DDS; (iii) non-breast-fed with high DDS; and (iv) breast-fed with high DDS (optimal). Interactions between age, energy intake and complementary feeding patterns were included.

Philippines.

Infants (n 2822) measured bimonthly from 6 to 24 months.

Breast-feeding (regardless of DDS) was significantly associated with higher LAZ (until 24 months) and WAZ (until 20 months). For example, at 6 months, breast-fed boys with low DDS were 0·246 (95 % CI 0·191, 0·302) sd longer and 0·523 (95 % CI 0·451, 0·594) sd heavier than the referent group. There was no significant difference in size between breast-fed infants with high v. low DDS. Similarly, high DDS conferred no advantage in LAZ or WAZ among non-breast-fed infants. There were modest correlations between the 7-point DDS and nutrient intakes but these correlations were substantially attenuated after energy adjustment. We elucidated several interactions between sex, age, energy intake and complementary feeding patterns.

These results demonstrate the importance of prolonged breast-feeding up to 24 months. The DDS provided qualitative information on infant diets but did not confer a significant advantage in LAZ or WAZ.

The present study aimed to translate the English version of the Nutritional Form For the Elderly into Simplified Chinese, as well as to test the reliability (homogeneity and stability) and validity (content and construct validity) of the Chinese version of the Nutritional Form For the Elderly (NUFFE-CHI).

The study adopted a cross-sectional design. The English version of the NUFFE was translated into Simplified Chinese and a questionnaire survey was conducted. The data were analysed with statistical methods to estimate the homogeneity, stability, content and construct validity.

Jinzhou City, China.

A total number of 701 community-dwelling older adults answered the questionnaire, including background variables and the NUFFE-CHI. A small group of the participants (n 50) completed the NUFFE-CHI twice for test–retest reliability.

Cronbach’s α was 0·65 and the split-half reliability was 0·67. Item-to-total correlation analyses showed that the scale has sufficient internal consistency. The test–retest reliability regarding the total scores of NUFFE-CHI was reflected in an intra-class correlation coefficient of 0·88. The intra-class correlation coefficients between the test and retest of the NUFFE-CHI items varied between 0·43 and 0·98. A content validity index of 0·83 explained good content validity. Construct validity was demonstrated in an exploratory factor analysis with a six-factor solution, explaining 57·65 % of the variance.

This first testing of the NUFFE-CHI indicates sufficient evidence for reliability, content and construct validity. Further testing studies regarding homogeneity, concurrent validity, sensitivity and specificity are required before the NUFFE-CHI can be used as a screening instrument in clinical settings and in research.

To investigate the predictors of wasting, stunting and low mid-upper arm circumference among children aged 6–59 months in Somalia using data from household cross-sectional surveys from 2007 to 2010 in order to help inform better targeting of nutritional interventions.

Cross-sectional nutritional assessment surveys using structured interviews were conducted among communities in Somalia each year from 2007 to 2010. A two-stage cluster sampling methodology was used to select children aged 6–59 months from households across three livelihood zones (pastoral, agro-pastoral and riverine). Predictors of three anthropometric measures, weight-for-height (wasting), height-for-age (stunting) and mid-upper arm circumference, were analysed using Bayesian binomial regression, controlling for both spatial and temporal dependence in the data.

The study was conducted in randomly sampled villages, representative of three livelihood zones in Somalia.

Children between the ages of 6 and 59 months in Somalia.

The estimated national prevalence of wasting, stunting and low mid-upper arm circumference in children aged 6–59 months was 21 %, 31 % and 36 %, respectively. Although fever, diarrhoea, sex and age of the child, household size and access to foods were significant predictors of malnutrition, the strongest association was observed between all three indicators of malnutrition and the enhanced vegetation index. A 1-unit increase in enhanced vegetation index was associated with a 38 %, 49 % and 59 % reduction in wasting, stunting and low mid-upper arm circumference, respectively.

Infection and climatic variations are likely to be key drivers of malnutrition in Somalia. Better health data and close monitoring and forecasting of droughts may provide valuable information for nutritional intervention planning in Somalia.

Diet in adolescence is important not only because of adolescents’ rapid growth but also due to its influence on future chronic diseases. On the other hand, dietary quality indices are noteworthy and useful approaches to evaluate dietary intakes. Thus the present study was conducted to assess dietary quality indices in adolescents.

Cross-sectional.

The data were collected from schools in Isfahan, Iran.

Female students (n 265) aged 11–13 years were enrolled using systematic cluster-random sampling in Isfahan (Iran). Dietary intakes were assessed by a validated FFQ. Diet quality indices including dietary diversity score (DDS), the Healthy Eating Index (HEI) and mean adequacy ratio (MAR) across ten nutrients were calculated.

Mean DDS, HEI score and MAR were 6·15 (sd 1·61) out of 10 points, 63·90 (sd 19·86) out of 100 points and 1·32 (sd 0·61), respectively. Mean nutrient adequacy ratio of all nutrients was above 1 except for vitamin D (0·53 (sd 0·51)). Those in the highest tertile of DDS had the most favourable anthropometric variables in comparison to the lowest tertile. There were no significant associations between HEI score and BMI, central or abdominal obesity and blood pressure. Those in the highest tertile of MAR had higher BMI, waist circumference and hip circumference.

Diet quality of Isfahani adolescents needs improvement. It may imply the necessity of implementing nutritional instructive policies in this age group and their parents.

Weight gained during pregnancy and postpartum weight retention might contribute to obesity in women of childbearing age. Whether breast-feeding (BF) may decrease postpartum weight retention (PPWR) is still controversial. The purpose of our systematic review and meta-analysis was to investigate the relationship between BF and PPWR.

Three databases were systematically reviewed and the reference lists of relevant articles were checked. Meta-analysis was performed to quantify the pooled standardized mean differences (SMD) of BF on PPWR by using a random-effect model. Heterogeneity was tested using the χ2 test and I2 statistics. Publication bias was estimated from Egger’s test (linear regression method) or Begg’s test (rank correlation method).

Among 349 search hits, eleven studies met the inclusion criteria for the meta-analysis. Seven studies were conducted in the USA, one in Brazil, one in France, one in Georgia and one in Croatia. Compared with formula-feeding, BF for 3 to ≤6 months seemed to have a negative influence on PPWR and if BF continued for >6 months had little or no influence on PPWR. In a subgroup meta-analysis, the results did not change substantially after the analysis had been classified by available confounding factors. There was no indication of a publication bias from the result of either Egger’s test or Begg’s test.

Although the available evidence held belief that BF decreases PPWR, more robust studies are needed to reliably assess the impact of patterns and duration of BF on PPWR.

Food guides are important tools for nutrition education. While developing a food guide in Benin, the objective was to determine the daily number of servings per food group and the portion sizes of common foods to be recommended.

Linear programming (LP) was used to determine, for each predefined food group, the optimal number and size of servings of commonly consumed foods. Two types of constraints were introduced into the LP models: (i) WHO/FAO Recommended Nutrient Intakes and dietary guidelines for the prevention of chronic diseases; and (ii) dietary patterns based on local food consumption data recently collected in southern Benin in 541 adults. Dietary intakes of the upper tertile of participants for diet quality based on prevention and micronutrient adequacy scores were used in the LP algorithms.

Southern area of the Republic of Benin.

Local key-players in nutrition (n 30) from the government, academic institutions, international organizations and civil society were partners in the development of the food guide directed at the population.

The number of servings per food group and the portion size for eight age–sex groups were determined. For four limiting micronutrients (Fe, Ca, folate and Zn), local diets could be optimized to meet only 70 % of the Recommended Nutrient Intakes, not 100 %.

It was possible to determine the daily number of servings and the portion sizes of common foods that can be recommended in Benin with the help of LP to optimize local diets, although Recommended Nutrient Intakes were not fully met for a few critical micronutrients.

With political support from the Danish Organic Action Plan 2020, organic public procurement in Denmark is expected to increase. In order to evaluate changes in organic food procurement in Danish public kitchens, reliable methods are needed. The present study aimed to compare organic food procurement measurements by two methods and to collect and discuss baseline organic food procurement measurements from public kitchens participating in the Danish Organic Action Plan 2020.

Comparison study measuring organic food procurement by applying two different methods, one based on the use of procurement invoices (the Organic Cuisine Label method) and the other on self-reported procurement (the Dogme method). Baseline organic food procurement status was based on organic food procurement measurements and background information from public kitchens.

Public kitchens participating in the six organic food conversion projects funded by the Danish Organic Action Plan 2020 during 2012 and 2013.

Twenty-six public kitchens (comparison study) and 345 public kitchens (baseline organic food procurement status).

A high significant correlation coefficient was found between the two organic food procurement measurement methods (r=0·83, P<0·001) with measurements relevant for the baseline status. Mean baseline organic food procurement was found to be 24 % when including measurements from both methods.

The results indicate that organic food procurement measurements by both methods were valid for the baseline status report of the Danish Organic Action Plan 2020. Baseline results in Danish public kitchens suggest there is room for more organic as well as sustainable public procurement in Denmark.

Promotion of healthy eating can no longer be postponed as a priority, given the alarming growth rate of chronic degenerative diseases in Western countries. We elaborated a nutrieconomic model to assess and identify the most nutritious and affordable food choices.

Seventy-one food items representing the main food categories were included and their nationally representative prices monitored. Food composition was determined using CRA-NUT (Centro di Ricerca per gli Alimenti e la Nutrizione) and IEO (Istituto Europeo di Oncologia) databases. To define food nutritional quality, the mean adequacy ratio and mean excess ratio were combined. Both prices and nutritional quality were normalised for the edible food content and for the recommended serving sizes for the Italian adult population.

Stores located in different provinces throughout Italy.

Not applicable.

Cereals and legumes presented very similar nutritional qualities and prices per serving. Seasonal fruits and vegetables presented differentiated nutritional qualities and almost equal prices. Products of animal origin showed similar nutritional qualities and varied prices: the best nutrieconomic choices were milk, oily fish and poultry for the dairy products, fish and meat groups, respectively.

Analysing two balanced weekly menus, our nutrieconomic model was able to note a significant decrease in cost of approximately 30 % by varying animal-protein sources without affecting nutritional quality. Healthy eating does not necessarily imply spending large amounts of money but rather being able to make nutritionally optimal choices. The nutrieconomic model is an innovative and practical way to help consumers make correct food choices and nutritionists increase the compliance of their patients.

To examine the association between women’s empowerment in agriculture and nutritional status among children under 2 years of age in rural Nepal.

Cross-sectional survey of 4080 households conducted in 2012. Data collected included: child and maternal anthropometric measurements; child age and sex; maternal age, education, occupation and empowerment in agriculture; and household size, number of children, religion, caste and agro-ecological zone. Associations between the Women’s Empowerment in Agriculture Index (WEAI)’s Five Domains of Empowerment (5DE) sub-index and its ten component indicators and child length-for-age Z-scores (LAZ) and weight-for-length Z-scores (WLZ) were estimated, using ordinary least-squares regression models, with and without adjustments for key child, maternal and household level covariates.

Two hundred and forty rural communities across sixteen districts of Nepal.

Children under 24 months of age and their mothers (n 1787).

The overall WEAI 5DE was positively associated with LAZ (β=0·20, P=0·04). Three component indicators were also positively associated with LAZ: satisfaction with leisure time (β=0·27, P<0·01), access to and decisions regarding credit (β=0·20, P=0·02) and autonomy in production (β=0·10, P=0·04). No indicator of women’s empowerment in agriculture was associated with WLZ.

Women’s empowerment in agriculture, as measured by the WEAI 5DE and three of its ten component indicators, was significantly associated with LAZ, highlighting the potential role of women’s empowerment in improving child nutrition in Nepal. Additional studies are needed to determine whether interventions to improve women’s empowerment will improve child nutrition.

The development of type 1 diabetes (T1D) is potentially influenced by nutrition. The aim of our study was to assess food and nutrient intakes of children at increased risk of T1D.

Dietary intake of the last 4 weeks was assessed using a diet history interview. The daily nutrient and food intakes were compared with the German Dietary Reference Intakes, the Optimized Mixed Diet recommendations and those of a representative sample of children from the EsKiMo study.

Children included in the analysis participated in the prospective TEENDIAB study.

First-degree relatives of people with T1D (n 268), aged 8–12 years.

The TEENDIAB children consumed 52·0 % of their total energy from carbohydrates, 32·6 % from fat and 14·3 % from protein. Compared with the reference values, their intake was lowest for folate at 61·3 % of the reference, for iodine at 58·1 % and for vitamin D at 8·9 %, and exceeded the reference for vitamin K about 5-fold, for Na about 3·5-fold and for protein about 1·5-fold. Their nutrient intakes were similar to those of a control cohort without increased T1D risk. The consumption of non-desirable food groups (meat products, sweets/snacks) was above the recommendations and the consumption of desirable food groups (fruits, vegetables, carbohydrate-rich foods) was below the recommendations.

The TEENDIAB children had intakes considerably below the recommendations for vitamin D, iodine, folate and plant-based foods, and intakes above for vitamin K, Na, protein, meat products and sweets/snacks. They showed similar dietary patterns to non-risk children.

To assess the validity and reliability of the Arabic version of the Household Food Insecurity Access Scale (HFIAS) in rural Lebanon.

A cross-sectional study on a sample of households with at least one child aged 0–2 years. In a one-to-one interview, participants completed an adapted Arabic version of the HFIAS. In order to evaluate the validity of the HFIAS, basic sociodemographic information, anthropometric measurements of the mother and child, and dietary intake data of the child were obtained. In order to examine reproducibility, the HFIAS was re-administered after 3 months.

Rural Lebanon.

Mother and child pairs (n 150).

Factor analysis of HFIAS items revealed two factors: ‘insufficient food quality’ and ‘insufficient food quantity’. Using Pearson's correlation, food insecurity was inversely associated with mother's and father's education levels, number of cars and electrical appliances in the household, income, weight-for-age and length-for-age of the child and the child's dietary adequacy. In contrast, mother's BMI and crowding index were positively associated with food insecurity scores (P < 0·05 for all correlations). Cronbach's α of the scale was 0·91. A moderate correlation was observed between the two administrations of the questionnaire (intra-class correlation = 0·58; P < 0·05).

Our findings indicated that the adapted Arabic version of the HFIAS is a valid and reliable tool to assess food insecurity in rural Lebanon, lending further evidence to the utility of the HFIAS in assessing food insecurity in culturally diverse populations.

Food neophobia has been associated with decreased consumption of vegetables mainly among children. We hypothesized that food neophobia in adults is also associated with lower overall dietary quality and higher BMI.

Data for the present cross-sectional analyses were derived from parents in a follow-up family study.

The STEPS study, a longitudinal study of health and development of a cohort of children born in south-west Finland.

The parents, 1178 women (age 19–45 years, mean 32·2 years) and 1013 men (age 18–57 years, mean 34·1 years), completed a questionnaire at home when their child was 13 months old. The questionnaire included the Food Neophobia Scale (FNS; range 10–70), the Index of Diet Quality (IDQ; range 0–16) and a measure of fruit and vegetable consumption. At that time the participants’ height and weight were also measured by a research nurse to calculate BMI.

Compared with the food neophilics (FNS score 10–24), the food neophobics (FNS score 40–70) consumed fewer vegetables (women: 15 v. 10 portions/week; men: 13 v. 7 portions/week), scored lower on the IDQ (women: 9·7 v. 8·5; men: 8·8 v. 7·8) and had higher BMI (women: 24·2 v. 26·0 kg/m2; men: 26·5 v. 27·5 kg/m2) as tested by one-way ANOVA, with all P values <0·001 in women and <0·05 in men. The food neophobics followed a diet lower in nutritional quality than did the food neophilics, especially regarding vegetables.

Food neophobia may complicate adaptation to dietary recommendations and predispose to overweight.

The present study examined whether maternal diet and early infant feeding experiences relating to being breast-fed and complementary feeding influence the range of healthy foods consumed in later childhood.

Data from four European birth cohorts were studied. Healthy Plate Variety Score (HPVS) was calculated using FFQ. HPVS assesses the variety of healthy foods consumed within and across the five main food groups. The weighted numbers of servings consumed of each food group were summed; the maximum score was 5. Associations between infant feeding experiences, maternal diet and the HPVS were tested using generalized linear models and adjusted for appropriate confounders.

The British Avon Longitudinal Study of Parents and Children (ALSPAC), the French Etude des Déterminants pre et postnatals de la santé et du développement de L’Enfant study (EDEN), the Portuguese Generation XXI Birth Cohort and the Greek EuroPrevall cohort.

Pre-school children and their mothers.

The mean HPVS for each of the cohorts ranged from 2·3 to 3·8, indicating that the majority of children were not eating a full variety of healthy foods. Never being breast-fed or being breast-fed for a short duration was associated with lower HPVS at 2, 3 and 4 years of age in all cohorts. There was no consistent association between the timing of complementary feeding and HPVS. Mother’s HPVS was strongly positively associated with child’s HPVS but did not greatly attenuate the relationship with breast-feeding duration.

Results suggest that being breast-fed for a short duration is associated with pre-school children eating a lower variety of healthy foods.

To assess the prevalence of household food insecurity (FI) in France and to describe its associations with socio-economic factors, health behaviours, diet quality and cost (estimated using mean food prices).

Cross-sectional nationally representative survey. FI was assessed using an adapted version of the US Department of Agriculture’s Food Insufficiency Indicator; dietary intake was assessed using a 7 d open-ended food record; and individual demographic, socio-economic and behavioural variables were assessed using self-administered questionnaires and interviews. Individuals experiencing FI were compared with food-secure individuals, the latter being divided into four categories according to quartiles of their income per consumption unit (FS1 to FS4). Differences among categories were analysed using χ2 tests, ANOVA and tests for trend.

Individual and National Dietary Survey (INCA2), 2006–2007.

Adults aged 18–79 years (n 2624).

Individuals experiencing FI represented 12·2 % of the population. They were on average younger, more frequently women and single parents with children compared with those in the other four categories. Their mean income per consumption unit was higher than that in the FS1 category, but they reported poorer material and housing conditions. The prevalence of smoking and the mean daily time spent watching television were also higher in the FI category. No significant difference among categories was found for energy intake, but mean intakes of fruits, vegetables and fish were lower, and diet quality was slightly but significantly poorer in the FI category. Daily diet cost was also lower in the FI category.

France is not spared by FI. FI should be routinely monitored at the national level and research should be promoted to identify effective strategies to reduce nutrition inequalities in France.

To evaluate the accuracy of the most commonly used anthropometric-based equations in the estimation of percentage body fat (%BF) in both normal-weight and overweight women using air-displacement plethysmography (ADP) as the criterion measure.

A comparative study in which the equations of Durnin and Womersley (1974; DW) and Jackson, Pollock and Ward (1980) at three, four and seven sites (JPW3, JPW4 and JPW7) were validated against ADP in three groups. Group 1 included all participants, group 2 included participants with a BMI<25·0 kg/m2 and group 3 included participants with a BMI≥25·0 kg/m2.

Human Performance Laboratory, Institute for Sport and Health, University College Dublin, Republic of Ireland.

Forty-three female participants aged between 18 and 55 years.

In all three groups, the %BF values estimated from the DW equation were closer to the criterion measure (i.e. ADP) than those estimated from the other equations. Of the three JPW equations, JPW3 provided the most accurate estimation of %BF when compared with ADP in all three groups.

In comparison to ADP, these findings suggest that the DW equation is the most accurate anthropometric method for the estimation of %BF in both normal-weight and overweight females.

Knowledge of the types and quantities of foods and drinks available in family homes supports the development of targeted intervention programmes for obesity prevention or management, or for overall diet improvement. In the UK, contemporary data on foods that are available within family homes are lacking. The present study aimed to explore home food and drink availability in UK homes.

An exploratory study using researcher-conducted home food availability inventories, measuring all foods and drinks within the categories of fruits, vegetables, snack foods and beverages.

Bradford, a town in the north of the UK.

Opportunistic sample of mixed ethnicity families with infants approximately 18 months old from the Born in Bradford birth cohort.

All homes had at least one type of fruit, vegetable and snack available. Fresh fruits commonly available were oranges, bananas, apples, satsumas and grapes. Commonly available fresh vegetables included potatoes, cucumber, tomatoes and carrots. The single greatest non-fresh fruit available in homes was raisins. Non-fresh vegetables contributing the most were frozen mixed vegetables, tinned tomatoes and tinned peas. Ethnic differences were found for the availability of fresh fruits and sugar-sweetened beverages, which were both found in higher amounts in Pakistani homes compared with White homes.

These data contribute to international data on availability and provide an insight into food availability within family homes in the UK. They have also supported a needs assessment of the development of a culturally specific obesity prevention intervention in which fruits and vegetables and sugar-sweetened beverages are targeted.

To examine national patterns in cooking frequency and diet quality among adults in the USA, overall and by weight-loss intention.

Analysis of cross-sectional 24 h dietary recall and interview data. Diet quality measures included total kilojoules per day, grams of fat, sugar and carbohydrates per day, fast-food meals per week, and frozen/pizza and ready-to-eat meals consumed in the past 30 d. Multivariable regression analysis was used to test associations between frequency of cooking dinner per week (low (0–1), medium (2–5) and high (6–7)), dietary outcomes and weight-loss intention.

The 2007–2010 National Health and Nutrition Examination Survey.

Adults aged 20 years and over (n 9569).

In 2007–2010, 8 % of adults lived in households in which someone cooked dinner 0–1 times/week and consumed, on an average day, 9627 total kilojoules, 86 g fat and 135 g sugar. Overall, compared with low cookers (0–1 times/week), a high frequency of cooking dinner (6–7 times/week) was associated with lower consumption of daily kilojoules (9054 v. 9627 kJ, P=0·002), fat (81 v. 86 g, P=0·016) and sugar (119 v. 135 g, P<0·001). Individuals trying to lose weight consumed fewer kilojoules than those not trying to lose weight, regardless of household cooking frequency (2111 v. 2281 kJ/d, P<0·006).

Cooking dinner frequently at home is associated with consumption of a healthier diet whether or not one is trying to lose weight. Strategies are needed to encourage more cooking among the general population and help infrequent cookers better navigate the food environment outside the home.

The present study validates a revised scale measuring individuals’ level of the ‘engagement in dietary behaviour’ aspect of ‘critical nutrition literacy’ and describes how background factors affect this aspect of Norwegian tenth-grade students’ nutrition literacy.

Data were gathered electronically during a field trial of a standardised sample test in science. Test items and questionnaire constructs were distributed evenly across four electronic field-test booklets. Data management and analysis were performed using the RUMM2030 item analysis package and the IBM SPSS Statistics 20 statistical software package.

Students responded on computers at school.

Seven hundred and forty tenth-grade students at twenty-seven randomly sampled public schools were enrolled in the field-test study. The engagement in dietary behaviour scale and the self-efficacy in science scale were distributed to 178 of these students.

The dietary behaviour scale and the self-efficacy in science scale came out as valid, reliable and well-targeted instruments usable for the construction of measurements.

Girls and students with high self-efficacy reported higher engagement in dietary behaviour than other students. Socio-economic status and scientific literacy – measured as ability in science by applying an achievement test – did not correlate significantly different from zero with students’ engagement in dietary behaviour.