Adequate zinc nutriture is critically important for human health, but the development of programmes to control zinc deficiency is limited by the lack of reliable information on population zinc status. The present analyses were conducted to: (1) estimate the absorbable zinc content of national food supplies; (2) compare this information with theoretical population requirements for zinc; and (3) use these results to predict national risks of inadequate zinc intake.

Setting and design: National food balance data were obtained for 176 countries from the Food and Agriculture Organization of the United Nations. The amount of absorbable zinc in these foods was estimated from food composition data, and zinc absorption was predicted using a model developed by the International Zinc Nutrition Consultative Group (IZiNCG). Demographic data were obtained from United Nations estimates, and age- and sex-specific physiological requirements for absorbable zinc were estimated using IZiNCG recommendations.

Results and conclusions: The mean per capita absorbable zinc content of national food supplies ranged from 2.98–3.01 mg day−1 in Western Europe and USA & Canada to 2.09 mg day−1 in Southeast Asia. The estimated percentage of individuals at risk of inadequate zinc intake ranged from 9.3–9.5% in the regions of North Africa & Eastern Mediterranean and USA & Canada to 33.1% in Southeast Asia. Overall, approximately 20.5% of the world's population is estimated to be at risk of inadequate zinc intake. Data on the absorbable zinc content of national food supplies can be used to determine whether further assessments of population zinc status and development of intervention programmes are warranted.

Adequate zinc nutriture is critically important for human health, but the development of programmes to control zinc deficiency is limited by the lack of reliable information on population zinc status. The present analyses were conducted to: (1) estimate the absorbable zinc content of national food supplies; (2) compare this information with theoretical population requirements for zinc; and (3) use these results to predict national risks of inadequate zinc intake.

Setting and design: National food balance data were obtained for 176 countries from the Food and Agriculture Organization of the United Nations. The amount of absorbable zinc in these foods was estimated from food composition data, and zinc absorption was predicted using a model developed by the International Zinc Nutrition Consultative Group (IZiNCG). Demographic data were obtained from United Nations estimates, and age- and sex-specific physiological requirements for absorbable zinc were estimated using IZiNCG recommendations.

Results and conclusions: The mean per capita absorbable zinc content of national food supplies ranged from 2.98–3.01 mg day−1 in Western Europe and USA & Canada to 2.09 mg day−1 in Southeast Asia. The estimated percentage of individuals at risk of inadequate zinc intake ranged from 9.3–9.5% in the regions of North Africa & Eastern Mediterranean and USA & Canada to 33.1% in Southeast Asia. Overall, approximately 20.5% of the world's population is estimated to be at risk of inadequate zinc intake. Data on the absorbable zinc content of national food supplies can be used to determine whether further assessments of population zinc status and development of intervention programmes are warranted.

To evaluate the impact of a low-cost nutritional intervention in changing the lifestyle of adults.

Randomised clinical trial.

Primary health-care centre in São José do Rio Preto, São Paulo State, Brazil.

We randomly assigned 104 adults (83 women and 21 men aged 30–65 years, body mass index 24–35 kg m−2, non-diabetic) into two groups: nutrition counselling and control. Each subject in the intervention group received three individualised nutritional counselling sessions during the first 6 months aimed at increasing intakes of fruits, vegetables and olive oil, reducing saturated fat and improving physical activity. Body composition, biochemical indicators and lifestyle were assessed at baseline and at 6 months and 1 year in both groups.

After 6 months of follow-up, body weight, waist circumference, diastolic blood pressure, fasting blood glucose, total and low-density lipoprotein cholesterol, total and saturated fat, and dietary energy and cholesterol levels showed a more significant decrease among subjects in the intervention group than in the control group (P<05). Moreover, the intervention group showed significantly greater improvement in each intervention goal, such as reduced intake of saturated fat and increased intakes of fruits, vegetables, fibre and olive oil (P<0.05). After 12 months of follow-up, most of the outcomes were maintained.

The low-cost nutritional intervention programme improved serum lipids profile and weight control, and appeared to be feasible for use at a primary health-care centre in a developing country.

To evaluate the impact of a low-cost nutritional intervention in changing the lifestyle of adults.

Randomised clinical trial.

Primary health-care centre in São José do Rio Preto, São Paulo State, Brazil.

We randomly assigned 104 adults (83 women and 21 men aged 30–65 years, body mass index 24–35 kg m−2, non-diabetic) into two groups: nutrition counselling and control. Each subject in the intervention group received three individualised nutritional counselling sessions during the first 6 months aimed at increasing intakes of fruits, vegetables and olive oil, reducing saturated fat and improving physical activity. Body composition, biochemical indicators and lifestyle were assessed at baseline and at 6 months and 1 year in both groups.

After 6 months of follow-up, body weight, waist circumference, diastolic blood pressure, fasting blood glucose, total and low-density lipoprotein cholesterol, total and saturated fat, and dietary energy and cholesterol levels showed a more significant decrease among subjects in the intervention group than in the control group (P<05). Moreover, the intervention group showed significantly greater improvement in each intervention goal, such as reduced intake of saturated fat and increased intakes of fruits, vegetables, fibre and olive oil (P<0.05). After 12 months of follow-up, most of the outcomes were maintained.

The low-cost nutritional intervention programme improved serum lipids profile and weight control, and appeared to be feasible for use at a primary health-care centre in a developing country.

To evaluate the efficacy of a community-based dietary intervention to reduce risk of micronutrient inadequacies in high-phytate maize-based Malawian diets.

Quasi-experimental post-test design with a non-equivalent control group.

Four villages in Mangochi District, Southern Malawi.

Households with children aged 3–7 years in two intervention (n = 200) and two control (n = 81) villages participated in a 6-month intervention employing dietary diversification, changes in food selection patterns, and modifications to food processing to reduce the phytate content of maize-based diets. Baseline comparability between the groups was confirmed via assessment of sociodemographic characteristics, anthropometry, knowledge and practices, morbidity, haemoglobin and hair zinc. After 12 months, knowledge and practices and dietary intakes were assessed by interactive 24-hour recalls, one during the food plenty and a second during the food shortage season. Nutrient adequacy for the two groups was compared via dietary quality indicators and predicted prevalence of inadequate intakes using the probability approach.

Intervention children had diets that were significantly more diverse and of a higher quality than those of controls. Median daily intakes of protein, calcium, zinc (total and available), haem iron, vitamin B12 and animal foods (grams; % of total energy) were higher (P<0.05) whereas phytate intakes, phytate/zinc and phytate/iron molar ratios were lower (P<0.01) in the intervention group; some spread of knowledge and practices to controls occurred.

Our community-based dietary strategies reduced the predicted prevalence of inadequate intakes of protein, calcium, zinc and vitamin B12, but not iron, in children from Malawian households with very limited resources.

To investigate the effects on maternal micronutrient status and infant growth of the increased maize prices that resulted from the southern African drought of 2001–2002.

Longitudinal cohort study.

A maternal and child health clinic in Lusaka, Zambia.

Maternal and infant health and nutrition data and maternal plasma were being collected for a study of breast-feeding and postpartum health. Samples and data were analysed according to whether they were collected before (June to December 2001), during (January 2002 to April 2003) or after (May 2003 to January 2004) the period of increased maize price. Season and maternal HIV status were controlled for in analyses.

Maize price increases were associated with decreased maternal plasma vitamin A during pregnancy (P = 0.028) and vitamin E postpartum (P = 0.042), with the lowest values among samples collected after May 2003 (vitamin A: 0.96 μmol l−1, 95% confidence interval (CI) 0.84–1.09, n = 38; vitamin E: 30.8 μmol mmol−1 triglycerides, 95% CI 27.2–34.8, n = 64) compared with before January 2002 (vitamin A: 1.03 μmol l−1, 95% CI 0.93–1.12, n = 104; vitamin E: 38.9 μmol mmol−1 triglycerides, 95% CI 34.5–43.8, n = 47). There were no significant effects of sampling date on maternal weight, haemoglobin or acute-phase proteins and only marginal effects on infant weight. Infant length at 6 and 16 weeks of age decreased progressively throughout the study (P-values for time of data collection were 0.51 at birth, 0.051 at 6 weeks and 0.026 at 16 weeks).

The results show modest effects of the maize price increases on maternal micronutrient status. The most serious consequence of the price increases is likely to be the increased stunting among infants whose mothers experienced high maize prices while pregnant. During periods of food shortages it might be advisable to provide micronutrient supplements even to those who are less food-insecure.

Previous research on the health transition and nutrition security in black South African households revealed the need for further research among farm workers who belong to the poorest population categories. This article gives an overview of the link between nutrition security, livelihoods and HIV/AIDS in South Africa, drawing conclusions for research among farm worker households.

Design and setting: A literature review, observations on farms and interviews with farmers and key informants were carried out in 2003 and 2004. Peer examination was done with South African and German researchers from the natural and social sciences.

Farm workers face poverty and nutrition insecurity and continue to be a tragically underserved population group, also in terms of research. There is furthermore a lack of in-depth research on underlying causes for nutrition security in South Africa and on the link with livelihoods, poverty and HIV/AIDS. Micro-social qualitative research from the household and gender perspective is required, as valid data on households, their internal dynamics and therefore the reflection of social realities are missing. A multidisciplinary research approach based on a new conceptual framework was developed to address the situation of farm worker households.

The outlined research contributes to existing programmes on farms in the North West Province, with the findings being valid also for other parts of southern Africa facing poverty, nutrition insecurity and HIV/AIDS.

To evaluate the reliability and validity of a six-item food security scale when self-administered by adolescents.

Cross-sectional questionnaire survey including the six-item food security measure, socio-economic variables and a food-frequency questionnaire.

Representative sample of 29 schools in Trinidad.

In total 1903 students aged approximately 16 years.

Item affirmatives ranged from 514 (27%) for the ‘balanced meal’ item to 128 (7%) for the ‘skipped or cut meals often’ item and 141 (7%) for the ‘hungry’ item. Item-score correlations ranged from 0.444 to 0.580. Cronbach's α was 0.77. Relative item severities from the Rasch model ranged from −1.622 (standard error 0.043) for the ‘balanced meal’ item to 1.103 (0.068) for the ‘skipped or cut meals often’ item and 0.944 (0.062) for the ‘hungry’ item. The ‘hungry’ item gave a slightly lower relative severity in boys than girls. Food insecurity was associated with household overcrowding (adjusted odds ratio comparing highest and lowest quartiles 2.61, 95% confidence interval 1.75 to 3.91), lack of pipe-borne water in the home, low paternal education or paternal unemployment. After adjusting for socio-economic variables, food insecurity was associated with less frequent consumption of fruit (0.75, 0.60 to 0.94) or fish (0.72, 0.58 to 0.88) but more frequent consumption of biscuits or cakes (1.47, 1.02 to 2.11).

The food security scale provides a valid, reliable measure in adolescents, although young people report being hungry but not eating relatively more frequently than adults. Food-insecure adolescents have low socio-economic position and may eat less healthy diets.

Longitudinal research has shown that eating fruit and vegetables during childhood has a positive impact on long-term health outcome from heart disease and asthma. However, recommendations for fruit and vegetable intakes in pre-school children are not as explicit as those for adults and few data exist on actual intakes of fruit and vegetables in this particular age group.

To describe fruit and vegetable intakes in the daily diets of a sample of pre-school children in Bradford, West Yorkshire, and to compare the findings with existing national UK data.

Pre-school children aged 3 and 4 years (n = 207). All subjects attended nurseries in the Airedale and Bradford South and West regions at the time of the study.

Dietary data were collected using the pre-validated CADET (Child and Diet Evaluation Tool) diary. All children were also seen individually in order to assess their awareness and preference for a range of fruit and vegetables.

Intakes of fruit and vegetables in this sample of pre-school children were below recommended levels. Only 16% of children in this sample were successfully eating fruit and vegetables on five occasions a day and conversely 14% ate no fruit and vegetables at all. Vegetable intakes were far lower than fruit intakes with 39% of the sample consuming no vegetables. There were statistically significant differences in median fruit and vegetable intakes between children with different demographic and lifestyle variables, such as which nursery they attended and what the highest educational qualification in the household was. Children's awareness of and preferences for different fruit and vegetables significantly affected their median intakes of fruit and vegetables.

Fruit and vegetable intakes in this sample of pre-school children were far lower than the recommended levels of 5 portions a day. A greater diversity of intakes should be encouraged and these data suggest that this may be attained by increasing children's awareness by exposing them to a wider range of fruit and vegetables.

We investigated whether life-long adherence to a vegetarian diet is associated with adult height, age at menarche, adult body weight and body mass index (BMI), used as indicators of growth, development and obesity, in a large sample of adults.

This was a cross-sectional study. Anthropometric data and information on age, ethnicity, education, age at menarche and age at becoming a vegetarian were obtained through a questionnaire. Self-reported height and weight were calibrated using predictive equations derived from a previous validation study.

United Kingdom.

The study includes 45 962 British men and women aged ≥ 20 years of whom 16 083 were vegetarians (not eating fish or meat).

In men and women, there were no significant differences in height, weight or BMI between life-long vegetarians (n = 125 (men) and n = 265 (women)) and people who became vegetarian at age ≥ 20 years (n = 3122 (men) and n = 8137 (women)). Nor was there a significant difference in age at menarche between life-long vegetarian women and women who became vegetarian at age ≥ 20 years.

This study suggests that, compared with people who become vegetarian when adult, life-long vegetarians do not differ in adult height, weight, BMI or age at menarche in women.

To examine if obesity status and socio-economic and lifestyle factors are associated with self-reported past food habit change, and also whether the level of obesity depends on the reason for change.

Cross-sectional analysis within the Malmo Diet and Cancer (MDC) study using data from the baseline examination and the extensive socio-economic and lifestyle questionnaire including questions of past food habit change. The risk of having changed food habits in the past was examined using logistic regression. Mean differences in obesity status across categories of reasons for past food habit change were examined using analysis of variance.

Malmö, the third largest city in Sweden.

A sub-sample (15 282 women and 9867 men) from the MDC cohort recruited from 1992 to 1996.

Individuals with body mass index (BMI) >30 kg m−2 had an increased risk of having reported past food habit change compared with individuals with BMI <25 kg m−2 (odds ratio (OR) = 1.63, 95% confidence interval (CI) = 1.48–1.83 for women; OR = 1.53, 95% CI = 1.32–1.76 for men). The highest level of obesity was observed among individuals who had changed their diet due to reasons related to the metabolic syndrome. Changers were more likely to be highly educated and to live alone, be retired, ex-smokers and non-drinkers at baseline.

Because past food habit change is related to obesity and other lifestyle and socio-economic factors, a complex confounding situation may exist that could seriously influence observed relationships between diet and disease. Studies need to collect information on past food habit change and take this information into account in the analysis and when interpreting study outcomes.

To investigate differences in reported physical activity levels and in perceived environmental and psychosocial correlates of activity between Portuguese and Belgian adults; and to analyse the relative contribution of environmental and psychosocial variables in explaining physical activity within different contexts in Portugal and Belgium.

Cross-sectional study.

One city in Portugal (Oeiras) and one in Belgium (Ghent).

In total 526 participants, 247 from Portugal and 279 from Belgium, completed the long International Physical Activity Questionnaire and a validated questionnaire on environmental and psychosocial correlates.

For the sum of all activities of at least moderate intensity, a significantly higher mean level of activity was found in Belgian adults (P < 0.001). However, comparable percentages of the Belgian (38%) and Portuguese (42%) samples did not meet the recommendation of 30 min per day. The variance explained by environmental factors was lower (1% to 8%) than by psychosocial factors (maximum 42%). Regression analyses showed activity-specific relations with environmental variables which were analogous in both countries. Walking/cycling for transportation and walking for recreation were related to social support from family and/or friends and to walkability and walking facilities in the neighbourhood. Recreational physical activity was mainly determined by social support, self-efficacy, and perceived benefits and barriers.

Activity campaigns addressing psychosocial determinants are needed to encourage leisure-time activity, while a combination of neighbourhood design changes and encouragement of social support in walking is warranted to increase walking in different contexts.

To evaluate gender differences for levels of physical activity, for sedentary behaviour and for psychosocial correlates in children, to evaluate whether psychosocial correlates cluster in meaningful ways and to examine whether physical activity and sedentary behaviour differ between children of clusters, differentiated by the level of perceived barriers and benefits, attitudes, social support and self-efficacy.

Cross-sectional study using the Flemish Physical Activity Questionnaire.

Questionnaires to be filled out by the children and one of their parents, contacted through the school system.

A sample of 1124 10- to 11-year-olds (579 boys and 545 girls).

Girls were found to be less active than boys, with boys scoring better for social support, perceived benefits and self-efficacy compared with girls. The way of clustering differed between boys and girls. Boys were allocated to three clusters: one cluster with positive correlates towards physical activity, labelled ‘positives’; one with negative correlates, labelled ‘negatives’; and one characterised mainly by high perceived barriers, labelled ‘hindered’;. In both genders the highest levels of physical activity were found in the ‘positives’;, the lowest in the ‘negatives’;. In girls a fourth cluster was identified, characterised mainly by low perceived barriers and low social support. Physical activity levels in the girls of this cluster, labelled ‘indifferents’;, were the second highest.

More research is needed to further characterise these clusters. To prevent the physical activity decline during the transition from childhood to adulthood, novel interventions need to be explored that focus on children of the clusters with the most negative correlates.

This study assessed and compared heath-related behaviours and nutrient and food group intakes between US-born and Korea-born Korean American women.

Cross-sectional analyses were performed for ethnic Koreans who participated in the Multiethnic Cohort Study in Hawaii and Los Angeles in 1993–1996. The sample included 492 Korean American women aged 45–75 years who were born in the USA (n = 274) or Korea (n = 218). Participants were recruited using driver's license files as a primary sampling source and completed a self-administered questionnaire, including a quantitative food frequency section.

The proportion overweight or obese was 31.4% in US-born and 9.4% in Korea-born women. US-born women had higher intakes of total fat and fat as a percentage of energy, and lower intakes of sodium, vitamin C, β-carotene and carbohydrate as a percentage of energy, than Korea-born women. Comparing intakes of food group servings from the Food Guide Pyramid, US-born women reported more whole grains, red meat and nuts, and less soy products, than did Korea-born women. US-born women also consumed fewer vegetables and fruit than those born in Korea. Few women in either group reported intakes that met the recommendations for dairy foods. Intake of discretionary fat from the Pyramid tip was higher in US-born than in Korea-born women.

These findings indicate that the acculturation of Korean immigrants affects dietary intakes in ways that may alter risks of several chronic diseases. Further studies will be necessary to examine the effects of dietary acculturation on disease patterns.

High-glycaemic-load diets may increase endometrial cancer risk by increasing circulating insulin levels and, as a consequence, circulating oestrogen levels. Given the paucity of epidemiological data regarding the relationship between dietary glycaemic index and glycaemic load and endometrial cancer risk, we sought to examine these associations using data from a prospective cohort study.

We examined the association between dietary glycaemic load and endometrial cancer risk in a cohort of 49 613 Canadian women aged between 40 and 59 years at baseline who completed self-administered food-frequency questionnaires between 1982 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000.

During a mean of 16.4 years of follow-up, we observed 426 incident cases of endometrial cancer. Hazard ratios for the highest versus the lowest quartile level of overall glycaemic index and glycaemic load were 1.47 (95% confidence interval (CI) = 0.90–2.41; P for trend = 0.14) and 1.36 (95% CI = 1.01–1.84; P for trend = 0.21), respectively. No association was observed between total carbohydrate or total sugar consumption and endometrial cancer risk. Among obese women (body mass index > 30 kg m−2) the hazard ratio for the highest versus the lowest quartile level of glycaemic load was 1.88 (95% CI = 1.08–3.29; P for trend = 0.54) and there was a 55% increased risk for the highest versus the lowest quartile level of glycaemic load among premenopausal women. There was also evidence to support a positive association between glycaemic load and endometrial cancer risk among postmenopausal women who had used hormone replacement therapy.

Our data suggest that diets with high glycaemic index or high glycaemic load may be associated with endometrial cancer risk overall, and particularly among obese women, premenopausal women and postmenopausal women who use hormone replacement therapy.

The objective of this analysis was to test the validity of the estimates of energy expenditure and sedentary lifestyle obtained through a self-administered questionnaire of physical activity for Spanish-speaking people adapted from US questionnaires (Nurses' Health Study and Health Professionals' Follow-up Study) using a triaxial accelerometer (RT3 Triaxial Research Tracker) as the reference.

Design and setting: Validation study, calculating the non-parametric correlation coefficients between the level of physical activity and sedentary lifestyle collected by the self-administered questionnaire and the triaxial accelerometer measurements. Percentage of misclassification and kappa coefficients were also calculated.

The study population consisted of a sample of 40 obese women who were participants of the SUN (Seguimiento Universidad de Navarra) project (a prospective cohort study among Spanish university alumni). They were selected because of their peculiar metabolic characteristics, in the search for a sub-optimal scenario for validity.

Physical activity during leisure time (estimated as MET-h week-1) derived from the self-administered questionnaire moderately correlated with kcal day-1 assessed through the accelerometer (Spearman's ρ = 0.507, 95% confidence interval (CI) 0.232, 0.707). The Spearman correlation between the ratio of sedentary lifestyle to physical activity obtained through the questionnaire and the direct estimation (RT3) was -0.578 (95% CI -0.754, -0.325). The kappa index was 0.25 (P = 0.002) when assessing the cross-classification into quintiles and 0.41 for the dichotomous estimation of a sedentary lifestyle. Only 2.5% of participants were misclassified by the questionnaire more than two quintiles apart from the estimates of the RT3.

The moderate values obtained for correlation in a sub-optimal scenario for validity and the low percentage of extreme misclassification suggest the validity of the questionnaire to assess physical activity in Spanish-speaking women aged 20–50 years.