We compared the dietary behaviour of three different household types and explored developmental trends in food choices following a life event.

The study is based on data from three Swiss Food Panel survey periods. A cross-sectional comparison between household types was conducted by using a one-way independent ANOVA. Repeated measures were analysed with a mixed ANCOVA to examine changes in dietary behaviour following a life event.

Participants in the survey filled in a questionnaire in the years 2010, 2011 and 2012.

The final sample consisted of 3559 persons with a mean age of 56 years (range 22–94 years; 46 % men). Seventy-two people moved in with their partner and sixty-five people reported the birth of their first child.

Cross-sectional evidence confirmed that women living in households with a partner reported higher consumption frequencies for meat and processed meats compared with those living alone. Men living in cohabitation had a higher vegetable intake. The transitional effect of moving in with a partner, however, resulted in a higher intake of processed meats for both genders and a higher intake of pork and savoury items for men. Transition to motherhood was linked to an increase in vegetable consumption, while the transition to fatherhood did not change consumption patterns significantly.

Individuals in life-stage transitions are more likely to change their nutritional strategies and life events can be a window of opportunity for changes towards better food choices.

To determine the best anthropometric measurement among waist: height ratio (WHtR), BMI, waist:hip ratio (WHR) and waist circumference (WC) associated with high CHD risk in adults and to define the optimal cut-off point for WHtR.

Population-based cross-sectional study.

Balcova, Izmir, Turkey.

Individuals (n 10 878) who participated in the baseline survey of the Heart of Balcova Project. For each participant, 10-year coronary event risk (Framingham risk score) was calculated using data on age, sex, smoking status, blood pressure, serum lipids and diabetes status. Participants who had risk higher than 10 % were defined as ‘medium or high risk’.

Among the participants, 67·7 % were female, 38·2 % were obese, 24·5 % had high blood pressure, 9·2 % had diabetes, 1·5 % had undiagnosed diabetes (≥126 mg/dl), 22·0 % had high total cholesterol and 45·9 % had low HDL-cholesterol. According to Framingham risk score, 32·7 % of them had a risk score higher than 10 %. Those who had medium or high risk had significantly higher mean BMI, WHtR, WHR and WC compared with those at low risk. According to receiver-operating characteristic curves, WHtR was the best and BMI was the worst indicator of CHD risk for both sexes. For both men and women, 0·55 was the optimal cut-off point for WHtR for CHD risk.

BMI should not be used alone for evaluating obesity when estimating cardiometabolic risks. WHtR was found to be a successful measurement for determining cardiovascular risks. A cut-off point of ‘0·5’ can be used for categorizing WHtR in order to target people at high CHD risk for preventive actions.

To compare obese v. non-obese consumers in terms of their general food-related lifestyles and to explore possible food-related factors affecting obesity in Italy.

The data were collected using a self-completion questionnaire. Data included sociodemographic information, measures of the Food-Related Lifestyle scale (FRL) and self-reported weight and height. A logistic regression model was fitted for the sample with obesity as the dependent variable and sociodemographic characteristics and FRL dimensions as the independent variables.

The survey was carried out in Italy between October and November 2010.

One thousand respondents were recruited with equal quotas for men v. women. The sample was representative of the Italian population in term of age groups and geographic areas. The participants were over 18 years of age and were solely or jointly responsible for the family's food shopping.

Our analyses revealed that sociodemographic, economic and cultural variables affect the increasing rate of obesity in Italy. Obese respondents appeared to find more enjoyment from shopping and interest in cooking compared with non-obese ones. Moreover, they were more likely to find self-fulfilment in foods. However, obese respondents appeared to be less interested in the nutritional content of foods, suggesting their weak involvement in nutritional aspects when they eat. In fact, the obese respondents gave preference to snacks over meals.

The outcome of the study would suggest that in targeted interventions for public health purposes in order to address obesity, attention should be placed on the role that food plays in obese consumers’ lives.

Psychological distress, defined as symptoms of depression and anxiety, is an increasingly important public health issue in developing countries. Little is known about the extent to which adverse dietary factors are associated with psychological distress in South Asians. Our aim was to compare the associations of diet and psychological distress in men and women in Goa, India.

Cross-sectional study of consecutive attendees in nine urban and rural general practices in Goa, India in 2004–2005. All participants completed an FFQ on their dietary intake in a typical week. Psychological distress was measured using the Kessler Psychological Distress Scale (K10), a WHO-validated screening instrument.

Consecutive attendees (n 1512; 601 men and 911 women) aged 30 to 75 years participated. Moderate and high scores of psychological distress were detected in significantly more women than men (eighty-eight men v. 264 women, unadjusted OR = 0·39; 95 % CI 0·29, 0·52). Those who ate one or more portions of fish weekly had nearly half the prevalence of distress in both sexes (women, OR = 0·52; 95 % CI 0·29, 0·91; men, OR = 0·50; 95 % CI 0·25, 0·99) and this was independent of age, marital status, education, income, religion and living alone.

Psychological distress is significantly lower with fish intake in both sexes. Further longitudinal work is needed to establish temporal relationships. Addressing psychological distress is becoming an increasingly significant public health priority in both high- and low-income countries.

Identifying risk factors for insulin resistance in adolescence could provide valuable information for early prevention. The study sought to identify risk factors for changes in insulin resistance and fasting blood glucose levels.

Prospective cohort of girls participating in the National Heart, Lung, and Blood Institute Growth and Health Study.

USA.

Adolescent girls (n 774) assessed at the ages of 16–17 and 18–19 years. Over a 3-year period, measurements of fasting blood glucose and insulin and serum cotinine were taken, and dietary intake (3 d food diary), smoking status and physical activity levels were self-reported.

Improvements in homeostasis model assessment of insulin resistance (HOMA-IR) were associated with increases in the percentage of energy intake from polyunsaturated fats (β = −3·33, 95 % CI −6·28, −0·39, P = 0·03) and grams of soluble fibre (β = −5·20, 95 % CI −9·81, −0·59, P = 0·03) between the ages of 16–17 and 18–19 years; with similar findings for insulin. Transitioning into obesity was associated with an increase in insulin (β = 6·34, 95 % CI 2·78, 9·91, P < 0·001) and HOMA-IR (β = 28·77, 95 % CI 8·13, 49·40, P = 0·006). Serum cotinine concentrations at 16–17 years, indicating exposure to tobacco, were associated with large increases (β = 15·43, 95 % CI 6·09, 24·77, P < 0·001) in fasting blood glucose concentrations.

Increases in the percentage of energy from polyunsaturated fat and fibre, and avoidance of excess weight gain and tobacco exposure, could substantially reduce the risk of insulin resistance in late adolescence.

To assess micronutrient intakes and the prevalence of inadequacy in a sample of high-school pupils in Ouarzazate, Morocco.

Food records were compiled over three non-consecutive days by pre-trained pupils. Micronutrient intakes were estimated using the DIAL software, adapted to include foods commonly eaten in Morocco. The prevalence of inadequacy was estimated by the proportion of individuals with intakes below the Estimated Average Requirement (EAR) for vitamins B12, A and K, thiamin, riboflavin, niacin, pyridoxine, folate, ascorbic acid, iodine, Ca, Mg and P; below the Adequate Intake (AI) level for pantothenic acid, biotin, Na and K; and using the probability approach for Fe. Data were adjusted for intra-individual variation with exclusion of under-reporters.

Ouarzazate, a semi-urban region situated on the southern slopes of the High Atlas with little industrial development but an important tourism sector.

A self-selected sample of 312 pupils aged 15–19 years from the five public high schools. After exclusion of under-reporters, 293 remained for analysis.

The highest proportions of below-EAR/AI intakes were seen for pantothenic acid (girls 85·1 %, boys 78·0 %), biotin (boys 83·1 %, girls 79·4 %), thiamin (boys 66·9 %), folate (girls 93·1 %, boys 74·6 %), iodine (boys 94·9 %, girls 88·0 %) and Ca (girls 83·4 %, boys 74·6 %). Na intake was generally in excess whereas K intake was below the AI level. In general, girls had better-quality diets than boys, who appeared to consume more ‘empty calories’.

Our findings suggest that in this population of Moroccan adolescents, nutritional intervention and educational strategies are needed to promote healthy eating habits and correct micronutrient inadequacies. To provide reliable and precise estimates of nutrient intakes, an update of Moroccan food composition databases is urgently needed. We recommend that national authorities address these issues.

To examine the patterns of consumption of foods high in solid fats and added sugars (SoFAS) in Brazil.

Cross-sectional study; individual dietary intake survey. Food intake was assessed by means of two non-consecutive food records. Foods providing >9·1 % of energy from saturated fat, or >1·3 % of energy from trans fat, or >13 % of energy from added sugars per 100 g were classified as high in SoFAS.

Brazilian nationwide survey, 2008–2009.

Individuals aged ≥10 years old.

Mean daily energy intake was 8037 kJ (1921 kcal), 52 % of energy came from SoFAS foods. Contribution of SoFAS foods to total energy intake was higher among women (52 %) and adolescents (54 %). Participants in rural areas (43 %) and in the lowest quartile of per capita family income (43 %) reported the smallest contribution of SoFAS foods to total energy intake. SoFAS foods were large contributors to total saturated fat (87 %), trans fat (89 %), added sugar (98 %) and total sugar (96 %) consumption. The SoFAS food groups that contributed most to total energy intake were meats and beverages. Top SoFAS foods contributing to saturated fat and trans fat intakes were meats and fats and oils. Most of the added and total sugar in the diet was supplied by SoFAS beverages and sweets and desserts.

SoFAS foods play an important role in the Brazilian diet. The study identifies options for improving the Brazilian diet and reducing nutrition-related non-communicable chronic diseases, but also points out some limitations of the nutrient-based criteria.

The present study investigates whether public organic food procurement policies have the potential to induce changes in the school food service environment.

A comparative cross-national survey was conducted in public primary and/or secondary schools in Finland, Germany and Italy. The school food coordinators completed a web-based questionnaire on their attitudes, intentions and actions towards organic school food provision.

In Germany, 122 out of 2050 schools in the state of Hesse responded. In Finland, 250 out of 998 schools across the country responded. In Italy, 215 out of 940 schools from eight provinces responded.

School food coordinators in the sample of schools in the three countries.

The German and Finnish school food coordinators separately most agreed with the promotion of healthy eating habits (P < 0·001) and organic food (P < 0·001) by schools. The Finnish schools were most likely to adopt a food and nutrition policy (P < 0·001), a health-promoting school policy according to WHO principles (P < 0·001), to have a playground (P < 0·001), to involve physical activity themes in teaching (P = 0·012) and to have a canteen (P < 0·001). The Italian schools were most likely to involve the food and nutrition policy in pedagogical activities (P = 0·004), to serve nutritional school meals (P < 0·001) and to recommend children to eat healthily (P < 0·001). In the three countries, the non-organic schools were less likely to adopt a food and nutrition policy (P < 0·001), a WHO health-promoting policy (P < 0·001) and have a canteen (P = 0·017) than the organic schools.

The study suggests that there is a gap in the effects of public organic food procurement policy on building a healthier school food environment.

We aimed to assess the prevalence and associated factors of vitamin D deficiency in healthy adolescents and to determine parent–adolescent association in vitamin D status.

A cross-sectional study.

Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008–2009. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using 125I-labelled RIA kits. Vitamin D deficiency in adolescents was defined as 25(OH)D level <27·5 nmol/l, and 25(OH)D levels between 27·5 and <50 nmol/l were considered insufficient. For the parents, vitamin D deficiency was defined as 25(OH)D level <50 nmol/l.

The study population consisted of 2062 adolescents (1095 boys, 967 girls; aged 10–18 years) and their parents (1005 fathers, 1341 mothers).

Overall, 13·4 % of adolescents (boys 11·7 %, girls 15·4 %) were 25(OH)D deficient, 54·7 % were 25(OH)D insufficient. Prevalence of vitamin D deficiency increased with age (P < 0·0001). Parental vitamin D deficiency was more prevalent in vitamin D-deficient adolescents than in non-deficient adolescents (all P < 0·0001). In multivariate logistic regression analyses, predictors for vitamin D deficiency were senior high school students (OR = 3·45–4·33), winter/spring season (OR = 3·18–5·11/5·35–7·36) and parental vitamin D deficiency (OR = 1·78–4·88; all P < 0·05).

Vitamin D insufficiency is prevalent among healthy Korean adolescents and the parent–offspring association warrants vitamin D screening for family members of deficient individuals.

To identify behavioural patterns of protective and risk factors for non-communicable diseases (NCD) and to explore the association between these patterns and sociodemographic characteristics.

Principal component analysis was used to identify behavioural patterns from a list of twelve protective and risk factors for NCD. Linear regression was used to explore the association between the patterns and sociodemographic characteristics.

Participants from the Brazilian Surveillance System of Risk and Protective Factors for NCD through Telephone Interviews (VIGITEL) from the years 2009 and 2010 were included.

A sample of 108 706 adults was included in the analysis.

Two behavioural patterns were identified in the analysis, a ‘prudent pattern’ and a ‘risky pattern’. The first involved mostly protective behaviours, while the second one involved essentially the risky ones. Both the less prudent and the more risky behaviour patterns were concentrated in younger men, with lower education, from the more developed region.

Public policies to decrease NCD should be aware of the possible tendency towards behavioural patterns in order to be more effective.

The most accurate method to estimate Na and K intakes is to determine 24 h urinary excretions of these minerals. However, collecting 24 h urine is burdensome. Therefore it was studied whether spot urine could be used to replace 24 h urine samples.

Participants collected 24 h urine and kept one voiding sample separate. Na, K and creatinine concentrations were analysed in both 24 h and spot urine samples. Also 24 h excretions of Na and K were predicted from spot urine concentrations using the Tanaka and Danish methods.

In 2011 and 2012, urine samples were collected and brought to the study centre at Wageningen University, the Netherlands.

Women (n 147) aged 19–26 years.

According to p-aminobenzoic acid excretions, 127 urine collections were complete. Correlations of Na:creatinine, K:creatinine and Na:K between spot urine and 24 h urine were 0·68, 0·57 and 0·64, respectively. Mean 24 h Na excretion predicted with the Tanaka method was higher (difference 21·2 mmol/d, P<0·001) than the measured excretion of 131·6 mmol/d and mean 24 h Na excretion predicted with the Danish method was similar (difference 3·2 mmol/d, P=0·417) to the measured excretion. The mean 24 h K excretion predicted with the Tanaka method was higher (difference 13·6 mmol/d, P<0·001) than the measured excretion of 66·8 mmol/d. Bland–Altman plots showed large individual differences between predicted and measured 24 h Na and K excretions.

The ratios of Na:creatinine and K:creatinine in spot urine were reasonably well associated with their respective ratios in 24 h urine and appear to predict mean 24 h Na excretion of these young, Caucasian women.

To investigate possible associations of lifestyle patterns with obesity and fat mass in children.

Cross-sectional epidemiological study. Principal component analysis was used to identify lifestyle patterns.

Primary schools from four regions in Greece.

A total of 2073 schoolchildren (aged 9–13 years).

Children in the fourth quartile of the lifestyle pattern combining higher dairy foods with more adequate breakfast consumption were 39·4 %, 45·2 % and 32·2 % less likely to be overweight/obese and in the highest quartile of sum of skinfold thicknesses and fat mass, respectively, than children in the first quartile of this pattern. Similarly, children in the fourth quartile of a lifestyle pattern comprising consumption of high-fibre foods, such as fruits, vegetables and wholegrain products, were 27·4 % less likely to be in the highest quartile of sum of skinfold thicknesses than children in the first lifestyle pattern quartile. Finally, children in the fourth quartile of a lifestyle pattern characterized by more time spent on moderate-to-vigorous physical activity and more frequent meals were 38·0 %, 26·3 % and 29·5 % less likely to be overweight, centrally obese and in the highest quartile of fat mass, respectively, than their peers in the first quartile of this lifestyle pattern (all P < 0·05).

The current study identified three lifestyle patterns (i.e. one pattern comprising higher dairy consumption with a more adequate breakfast; a second pattern characterized by increased consumption of high-fibre foods; and a third pattern combining higher physical activity levels with more frequent meals), which were all related with lower odds of obesity and/or increased fat mass levels. From a public health perspective, promotion of these patterns among children and their families should be considered as one of the components of any childhood obesity preventive initiative.

To evaluate the prevalence of vitamin D deficiency and insufficiency, as well as their association with Hb and elevated blood lead levels (BLL) in children in China.

A cross-sectional and 1-year retrospective study.

Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, China.

Children aged from 6 months to 14 years living in south-west China who were taken to physical examinations (January–December 2011).

Of 1218 children included in the study, 25-hydroxyvitamin D (25(OH)D) concentration (mean 33·18 (sd 16·48) ng/ml) was deficient in 21·6 % and insufficient in 27·4 %, which were higher than the prevalence of both anaemia at 8·5 % and elevated BLL (Pb ≥ 10 μg/dl) at 1·8 %, but lower than mildly elevated BLL prevalence (5 μg/dl ≤ Pb < 10 μg/dl) at 56·9 %. There was a negative correlation between 25(OH)D concentration and BLL (r = −0·216, P < 0·001) while no significant relationship was found between 25(OH)D concentration and Hb (r = −0·012, P > 0·05). After multivariable adjustment, the significant predictors of 25(OH)D deficiency and insufficiency were increasing child age especially between 8 and 14 years (OR = 18·29; 95 % CI 10·14, 32·99; P < 0·001) and BLL (OR = 1·01; 95 % CI 1·00, 1·02; P = 0·045).

The prevalence of 25(OH)D deficiency and insufficiency was much higher than that of anaemia or elevated BLL in south-west China, and associated with increasing age and BLL.

To assess racial/ethnic differences in the diet in young children and the explanatory role of maternal BMI, immigrant status and perception of child's weight.

Among white, black and Hispanic 3-year-olds, we used negative binomial and linear regression to examine associations of race/ethnicity with foods and nutrients assessed by a validated FFQ.

Project Viva, Boston (MA), USA.

Children aged 3 years (n 898).

Mean age was 38·3 (sd 2·8) months; 464 (52 %) were boys and 127 mothers (14 %) were immigrants. After adjustment for sociodemographic factors, black and Hispanic children (v. white) had a higher intake of sugar-sweetened beverages (rate ratio (RR) = 2·59 (95 % CI 1·95, 3·48) and RR = 1·59 (95 % CI 1·07, 2·47), respectively) and lower intakes of skimmed/1 % milk (RR = 0·42 (95 % CI 0·33, 0·53) and RR = 0·43 (95 % CI 0·31, 0·61), respectively) and trans-fat (−0·10 (95 % CI −0·18, −0·03) % of energy and −0·15 (95 % CI −0·26, −0·04) % of energy, respectively). Among Hispanics only, a lower intake of snack food (RR = 0·83 (95 % CI 0·72, 0·98)) was found and among blacks only, a higher intake of fast food (RR = 1·28 (95 % CI 1·05, 1·55)) and lower intakes of saturated fat (−0·86 (95 % CI −1·48, −0·23) % of energy), dietary fibre (0·85 (95 % CI 0·08, 1·62) g/d) and Ca (−120 (95 % CI −175, −65) mg/d) were found. Being born outside the USA was associated with more healthful nutrient intakes and less fast food.

Three-year-old black and Hispanic (v. white) children ate more sugar-sweetened beverages and less low-fat dairy. Total energy intake was substantially higher in Hispanic children. Snack food (Hispanic children) and fat intakes (black children) tended to be lower. Children of immigrants ate less fast food and bad fats and more fibre.

To verify associations of income and education with nutrient intakes in Brazilian adults.

Data from the population-based National Dietary Survey conducted in 2008–2009. Family per capita income and education levels were categorized into quartiles. Prevalences of inadequate nutrient intakes and excessive intakes of saturated fat and Na were calculated by using the method prescribed by the National Cancer Institute. The Estimated Average Requirement was used as a reference for micronutrient intake. Linear regression models for both the independent and the mutually adjusted associations of education and income with nutrient intakes were tested. Interaction between education and income was tested.

Households (n 13 569) selected using a two-stage cluster sampling design.

Food records for two non-consecutive days were obtained for 21 003 Brazilian adults (aged 20–59 years).

For most of eleven nutrients, the prevalence of inadequate intake declined with increasing income and education levels; however, it remained high across all income and education quartiles. Excessive intake of saturated fat and low fibre intake increased with both variables. Most nutrients were independently associated with income and education in both sexes. Fe, vitamin B12 and Na intakes among women were associated only with education. There was an interaction between income and education for Na intake in men, P intake in women and Ca intake in both sexes.

Education is one important step to improve nutrient intakes in Brazil. Emphasis should be laid on enhancing dietary knowledge and formulating economic strategies that would allow lower-income individuals to adopt a healthy diet.

To investigate the association between eating behaviours (eating speed and energy intake of main meals) and overweight in pre-school children.

Cross-sectional study. Data consisted of measurements (height and weight), questionnaire information (eating behaviours of eating speed and overeating) and on-site observation data (meal duration and energy intake of main meals).

Seven kindergartens in Beijing, China.

Pre-school children (n 1138; age range 3·1–6·7 years old) from seven kindergartens participated in the study.

The multivariate-adjusted odds ratio of overweight in participants with parent-reported ‘more than needed food intake’ was 3·02 (95 % CI 2·06, 4·44) compared with the ‘medium food intake’ participants, and higher eating speed was associated with childhood overweight. For the two observed eating behaviours, each 418·7 kJ (100 kcal) increase of lunch energy intake significantly increased the likelihood for overweight by a factor of 1·445, and each 5-min increase in meal duration significantly decreased the likelihood for overweight by a factor of 0·861. Increased portions of rice and cooked dishes were significantly associated with overweight status (OR = 2·274; 95 % CI 1·360, 3·804 and OR = 1·378; 95 % CI 1·010, 1·881, respectively).

Eating speed and excess energy intake of main meals are associated with overweight in pre-school children.

To evaluate ethnic and anthropometric correlates of adiposity among a nationally representative, multi-ethnic, Trinidadian pre-school population.

Cross-sectional study conducted between June 2008 and July 2009.

Government and privately owned Early Childhood Care and Education Centres in Trinidad.

A total of 596 pre-school children (aged 31–73 months) from thirty-four schools had their weight, height, mid-upper arm circumference, waist circumference, biceps and triceps skinfold thicknesses measured by a registered dietitian using standard procedures. Percentage body fat was estimated using a foot-to-foot bioelectric impedance analyser (Tanita 531, Tokyo, Japan). Date of birth, religion and ethnicity were extracted from school records and pre-schoolers’ ethnicity was categorized as East Indian, African, Mixed (a combination of two or more ethnicities), Chinese or Caucasian.

Anthropometric variables explained significantly more of the variance in adiposity among girls (67·4–88·1 %) than boys (24·4–39·2 %; P < 0·0 0 1). Pre-schoolers of African descent were significantly taller, heavier and had higher abdominal fat and mid-upper arm circumference than their East Indian and Mixed counterparts (all P < 0·001). The overall prevalence of excess adiposity (≥25 % body fat) as determined by bioelectrical impedance was 14·6 %, while 2·9 % of the children were undernourished according to WHO weight-for-age criteria. Differences in anthropometry were non-existent between children attending government and private pre-schools.

Gender, ethnicity and anthropometry all explained excess adiposity in these pre-schoolers. These findings highlight the need to elucidate the mechanisms that may be involved in explaining these differences, particularly those of ethnic origin.

The present study aimed to model obesity trends and future obesity-related disease for nine countries in the Middle East; in addition, to explore how hypothetical reductions in population obesity levels could ameliorate anticipated disease burdens.

A regression analysis of cross-sectional data v. BMI showed age- and sex-specific BMI trends, which fed into a micro simulation with a million Monte Carlo trials for each country. We also examined two alternative scenarios where population BMI was reduced by 1 % and 5 %.

Statistical modelling of obesity trends was carried out in nine Middle East countries (Bahrain, Egypt, Iran, Jordan, Kuwait, Lebanon, Oman, Saudi Arabia and Turkey).

BMI data along with disease incidence, mortality and survival data from national and sub-national data sets were used for the modelling process.

High rates of overweight and obesity increased in both men and women in most countries. The burden of incident type 2 diabetes, CHD and stroke would be moderated with even small reductions in obesity levels.

Obesity is a growing problem in the Middle East which requires government action on the primary prevention of obesity. The present results are important for policy makers to know the effectiveness of obesity interventions on future disease burden.

To determine if children aged 1–6 years from non-Western immigrant families have lower serum 25-hydroxyvitamin D (25(OH)D) levels than children from Western-born families and examine which factors influence this relationship.

Cross-sectional study.

Toronto, Canada.

Healthy children (n 1540) recruited through the TARGet Kids! practice-based research network. Serum 25(OH)D concentrations of non-Western immigrants were compared with those of children from Western-born families. Children from non-Western immigrant families were defined as those born, or their parents were born, outside a Western country. Univariate and multiple linear regression analyses were used to identify factors which might influence this relationship.

Median age was 36 months, 51 % were male, 86 % had ‘light’ skin pigmentation, 55 % took vitamin D supplements, mean cow's milk intake was 1·8 cups/d and 27 % were non-Western immigrants. Median serum 25(OH)D concentration was 83 nmol/l, with 5 % having 25(OH)D < 50 nmol/l. Univariable analysis revealed that non-Western immigrant children had serum 25(OH)D lower by 4 (95 % CI 1·3, 8·0) nmol/l (P = 0·006) and increased odds of 25(OH)D < 50 nmol/l (OR = 1·9; 95 % CI 1·3, 2·9). After adjustment for known vitamin D determinants the observed difference attenuated to 0·04 (95 % CI −4·8, 4·8) nmol/l (P = 0·99), with higher cow's milk intake (P < 0·0001), vitamin D supplementation (P < 0·0001), summer season (P = 0·008) and increased age (P = 0·04) being statistically significant covariates. Vitamin D supplementation was the strongest explanatory factor of the observed difference.

There is an association between non-Western immigration and lower 25(OH)D in early childhood. This difference appears related to known vitamin D determinants, primarily vitamin D supplementation, representing opportunities for intervention.

To develop a child- and adolescent-appropriate physical activity frequency questionnaire (PAFQ) in Tunisia, North Africa.

A PAFQ was developed from a physical activity (PA) inventory that comprised major activity components (at home, preparing meals, school time, transport, non-sport leisure, sports, prayer and sleeping time). Then, type and duration of each activity undertaken during the past week were estimated. Total energy expenditure (TEE) estimated by the PAFQ was compared with data derived from two criterion methods: heart-rate monitoring (HRM) and a 24 h PA recall (24h-R), both collected during a 3 d period including one weekday and two weekend days.

Two elementary schools and two high schools of the most developed and urbanized area, Greater Tunis.

One hundred and forty-two volunteer children and adolescents aged 10–19 years.

The PAFQ strongly was correlated with both HRM (r = 0·70; 95 % CI 0·62, 0·76) and 24h-R (r = 0·81; 95 % CI 0·77, 0·84). It featured acceptable agreement with both criterion measures, slightly underestimating TEE compared with 24h-R (−2·8 %, mean of individual differences −272·7 kJ/d; 95 % CI −490·6, −57·4 kJ/d) and moderately overestimating it compared with HRM (+11·3 %, mean of individual differences +1106·2 kJ/d; 95 % CI 845·8, 1366·6 kJ/d). Reliability ranged from moderate to good (weighted kappa coefficients from 0·47 to 0·78 and intra-class correlation coefficients between 0·79 and 0·86 for energy expenditure by PA categories), indicating strong agreement between the two assessments.

This PAFQ could be useful in the description and surveillance of PA patterns or for the evaluation of population-based interventions directed at promoting PA in Tunisian children and adolescents.