To examine the effects of socioeconomic status and biocultural variables (planned pregnancy, prenatal care, timing of initiation of breast-feeding and caesarean section delivery) on breast-feeding duration in Peru using structural equation models.

Structural equation models were analysed with LISREL using data from the 1991–92 Peruvian Demographic and Health Survey.

Models were tested among 6020 women whose last child was born within 5 years of the survey and among 2711 women whose last child was born 2–5 years preceding the survey.

Unplanned pregnancy and socioeconomic status had a negative influence on breast-feeding duration. Prenatal care was positively associated with the timing of breast-feeding initiation in both samples and with breast-feeding duration in the whole sample. The timing of breast-feeding initiation was inversely associated with breast-feeding duration only in the sample of older children.

These results imply that an unplanned pregnancy, a delayed breast-feeding initiation, and higher socioeconomic status are risk factors for an earlier discontinuation of breast-feeding through complex mechanisms involving direct and indirect effects.

Dietary intake has long been looked upon as a potentially modifiable risk factor for gallbladder disease (GBD), here defined as either having gallstones or having had surgery for gallstones. This paper reviews the epidemiological evidence for an association between dietary intake and GBD, focusing on six dietary factors that have received the most attention in studies in this area: energy intake, fatty acids, cholesterol, carbohydrates and fibre, calcium and alcohol. The objectives of this review are to evaluate the potential usefulness of altering the diet to prevent GBD and to consider future research in this area.

We reviewed all English-language epidemiological studies on diet and cholelithiasis that were cross-sectional, cohort or case–control in design and that were indexed in the Medline database from 1966 to October 1997.

A positive association was suggested with simple sugars and inverse associations with dietary fibre and alcohol. No convincing evidence was found for a role for energy intake or intake of fat or cholesterol. Variable means of ascertaining cases and inaccurate measurement of dietary intake may contribute to variation in results across studies.

Some specific components of the diet that may affect GBD include simple sugars, fibre and alcohol, but whether risk for GBD can be reduced by altering intake of a specific dietary factor has not been established. Although no specific dietary recommendations can be made to reduce risk of GBD per se, a ‘healthy’ diet aimed at reducing risk of other diseases might be expected to reduce risk for GBD as well.

This article provides a comprehensive review of the change in vitamin A status and the extent of vitamin A deficiency among different population groups in Bangladesh up to the present time. The result of experience with different strategies and interventions designed to improve vitamin A status are then reviewed, leading to a discussion of key options for action, as well as important areas for research and evaluation.

All the available data have been examined in detail, including data from nationally representative samples and nationwide surveys, as well as small studies in different population groups. Reports on the effectiveness of different intervention programmes have been used.

Over the past three decades a number of studies, which include national nutrition surveys, have been carried out to investigate the prevalence of vitamin A deficiency among different population groups in Bangladesh, and they have demonstrated a significant public health problem. Studies have shown that the prevalence of severe deficiency, based on the prevalence of night blindness in preschool children, decreased from 3.6% in 1982–83 to 1.78% in 1989 and 0.6% in 1996. However, there is still a high prevalence of subclinical vitamin A deficiency, based on the biochemical assessment of serum retinol levels in preschool children, estimated mainly from hospital-based groups. Night blindness and Bitot's spot are also found to exist among school-age children and adolescents. Recent reports indicate that night blindness among rural mothers is as high as 1.4%. Only a limited number of studies, with small sample sizes, are available where serum retinol has been reported for school-age children, adolescents and pregnant women. Nevertheless, these studies confirm the presence of low levels of serum retinol and hence, the existence of subclinical vitamin A deficiency. Furthermore, the dietary intake of vitamin A in each population group has been found to be less than the Recommended Daily Allowance (RDA), indicating a significant risk of deficient intakes of vitamin A.

To address the problem of vitamin A deficiency, the government of Bangladesh started the Nutritional Blindness Programme in 1973. The main activities of the programme include vitamin A capsule (VAC) supplementation to children of 6 months to 6 years old, nutrition education to increase the production and consumption of vitamin A rich foods, and training of primary health-care workers on the clinical diagnosis and treatment of vitamin A deficiency, VAC distribution and nutrition education. Since 1988, as a long-term strategy, Helen Keller International has been implementing community home gardening promotion projects. To date, the possibility that foods may be fortified with vitamin A, has not been explored as a possible approach in Bangladesh.

Although short- to long-term prevention and control programmes are to some extent in place, to improve the situation of vitamin A deficiency, Bangladesh needs a more appropriate mix of interventions for the entire population. More operational research and evaluation are needed if a fully effective programme to alleviate the problem of vitamin A deficiency is to be developed. Finally, to achieve the goal of virtual elimination of vitamin A deficiency will require an integrated approach which brings together appropriate actions at every level, within and across the many sectors of society.

To explore British African-Caribbean (AfC) nutrient intake by migration status (place of birth), diet (traditional Caribbean or more European) and age and relate this ecologically to coronary heart disease (CHD) mortality rates.

Cross-sectional.

Inner-city Manchester, UK.

Two hundred and fifty-five adults of AfC origin aged 25–79 years, randomly sampled from population registers.

Caribbean-born people (mean age 56, and mean time in Britain 30 years) had significantly lower per cent energy from total and saturated fat than younger British-born AfC people (mean age 29 years) (31.3% vs. 35%, difference in total fat 3.7%, 95%CI 2–5%; in saturated fat 10.9% vs. 12.6%, difference 1.7%, 95%CI 1–2.5%). The Caribbean-born group also ate more fruit (+84 g day−1, 95%CI 36–132 g day−1) and green vegetables (+26 g day−1, 95%CI 3–49 g day−1). Men following a traditional diet (>= 5 days week−1) similarly had a lower per cent energy from fat, at 30.4%, than less traditional eaters, at 33.1% (difference 2.7%, 95%CI 0.7–4.8%). African-Caribbean women, at relatively greater CHD risk than AfC men, had higher body mass indices (BMIs) than AfC men. Compared with national data, AfC subjects consumed some 7% and 5% less energy from total fat and saturated fat, respectively, with over 9% more from carbohydrate. However, there was marked convergence towards the national average in the youngest AfC groups aged 25–34 years, whatever their place of birth.

Caribbean birthplace has an independent effect on total fat intake and percentage of energy from fat. Together with higher fruit and vegetable intake, these results are consistent with the dietary fat/antioxidant/CHD hypothesis.

To describe the extent of use of medicines by older people living in Britain, and to explore relationships with vitamin status indices.

The National Diet and Nutrition Survey of people aged 65 years and over collected data from a British sample during 1994–95. The present study has made novel use of it, to relate medicine use with biochemical indices of vitamin status.

Eighty postcode areas, selected randomly from mainland Britain.

1506 people, 65 years and over gave information about use of medication, and a 4-day weighed food record. Three-quarters gave blood for status indices.

78% of those living in the community and 93% of those in institutions were using medication. Certain vitamin status indices: plasma retinol, erythrocyte folate and riboflavin, paradoxically suggested better status in users than in non-users of antihypertensive, gastrointestinal, central nervous system, corticosteroid or diabetic drugs. There was evidence of a link with renal insufficiency, especially for plasma retinol, but neither this nor increased nutrient intake, acute phase effects or haemoconcentration could explain the paradoxical associations.

Caution is needed in interpreting certain vitamin status indices, especially in older people who are extensively using medicines. New vitamin indices are needed, to avoid confounding interferences.

The purpose of this trial was to compare three different iodine interventions.

School children aged 8–10 years were randomized into one of three groups: group A was provided with iodized salt by researchers with an iodine concentration of 25 ppm; group B purchased iodized salt from the market; and group C was similar to group B with the exception that they were given iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months after randomization.

The prevalence of abnormal thyroid volumes, based on the World Health Organization (WHO) body surface area reference > 97th percentile, was 18% at baseline and declined to less than 5% by 12 months in groups A and C, and to 9% after 18 months in group B. Results for goitre by palpation were similar. The median urinary iodine was 94 μgl−1 at baseline and increased in all groups to > 200 μgl−1 at the 6-month follow-up.

In this population of school children with initially a low to moderate level of iodine deficiency, the group receiving salt with 25 ppm (group A) was not iodine deficient on all indicators after 18 months of study. When the iodine content of the salt varied, such as in group B, by 18 months thyroid sizes had not yet achieved normal status.

The purpose of conducting this survey was to identify data on consumer attitudes towards and beliefs about physical activity, body weight and health among the 15 countries of the EU.

A cross-sectional study to get a picture of the attitudes to physical activity, body weight and health in the EU. For this, it was considered important that samples be nationally representative so that inferences drawn from the data could be applied to the population in each country as well as to the EU population as a whole. Using a non-probability sampling method employing quota controls (and the national weight) we obtained large sample sizes from each country which were nationally representative in terms of the variables age, sex and regional distribution. To ensure samples were truly nationally representative a national weight was used when analysing the data using the same characteristics as those used to define quotas. When examining pooled estimates for the total EU sample a population weight was applied.

In total, 15 239 subjects aged 15 years and upwards in the EU completed the survey. This article gives details on the methods used in carrying out the survey from design of the questionnaire to sample selection, questionnaire administration and analysis of the data. The methods and their limitations are discussed.

Although the benefits of physical activity regarding body-weight gain and health in general are now widely accepted, physical activity levels remain low among citizens in the western world. This could be attributed to certain attitudes and beliefs about physical activity. Identifying and understanding these parameters would be the first step in an attempt to increase the levels of physical activity in populations generally characterized as having a sedentary lifestyle.

The aim of the present study was to identify the attitudes and beliefs regarding physical activity, body weight and health in a nationally representative sample in the EU and in particular to explore the demographic and national (cultural) influences on attitudes towards physical activity.

In each member state of the EU, approximately 1000 adults aged 15 years and over, were selected to complete an interviewer-assisted face-to-face questionnaire. Overall, a sample of 15 239 individuals in the EU participated in the study. Subject selection was quota-controlled to ensure samples in each country were nationally representative.

On a European level wide variations were observed regarding the levels, beliefs and attitudes towards physical activity. More positive beliefs were observed among Finns, while less positive beliefs were observed among southern Europeans. A similar pattern was observed for attitudes, with the Portuguese having the highest percentage feeling that they do not need to be more physically active than they already are. However, most southern Europeans felt that a campaign would encourage them to become more active than they already are. On a demographic level, the youngest, more educated and most physically active subjects had more positive attitudes and beliefs towards physical activity and the health benefits derived from it; while for the overweight, beliefs and attitudes toward physical activity were related primarily to the benefits related to weight control.

Lower levels of physical activity, an unwillingness to become active among non-participants and confusion regarding the weight gain benefits and general health benefits of exercise were reported more frequently among southern Europeans and older and less educated subjects. The Finns scored highest in all these parameters, possibly due to the programmes implemented and the beliefs and behaviour changes observed in this country during the last few years. The actions taken in Finland and their benefits could be employed appropriately in the other European states.

To assess the nutritional status and dietary practices of 4–24-month-old children (under-twos) in a rural South African community.

Cross-sectional survey.

A low socioeconomic rural African community (Ndunakazi), approximately 60 km north-west of Durban, KwaZulu-Natal, South Africa.

Children (n = 115), 4–24 months old who attended growth monitoring posts in the area.

Of these under-twos, 37.3% had low vitamin A status (serum retinol < 20 μg dl−1), 65.2% were anaemic, 43.2% had serum ferritin levels < 10 μgl−1 (an indicator of low iron stores) and 15.3% were stunted. Breastfeeding was initiated by 99% of mothers. At the time of the survey, 80% of infants in the 4–12-month-old category and 56.9% of children in the 12–24-month-old category were being breastfed. Solid foods were introduced at 3.6 ± 0.8 months. Food intake reflected a high intake of carbohydrate-rich foods, and irregular intakes of fruit and vegetables, especially those rich in vitamin A. Foods of animal origin were not consumed regularly. Of these under-twos, 15.9% experienced an episode of diarrhoea during 2 weeks prior to the survey.

These under-twos had a poor vitamin A and iron status. Nutrition education, intervention programmes and feeding schemes should address micronutrient deficiencies, with the focus on the quality of the diet, rather than quantity.

To determine whether responses to simple dietary questions are associated with specific causes of death.

Self-reported frequency intakes of various classes of foods and data on confounding factors were collected at the baseline survey. Death notifications up to 31 December 1997 were ascertained from the Office for National Statistics. Relative risk (RR) of death and 95% confidence intervals (CI) associated with baseline dietary factors were calculated by Cox regression.

Prospective follow-up study based on five UK general practices.

Data were used from 11 090 men and women aged 35–64 years (81% of the eligible patient population) who responded to a postal questionnaire in 1989.

After 9 years of follow-up, 598 deaths were recorded, 514 of these among the 10 522 subjects with no previous history of angina. All-cause mortality was positively associated with age, smoking and low social class, as expected. Among the dietary variables, all-cause mortality was significantly reduced in participants who reported relatively high consumption of vegetables, puddings, cakes, biscuits and sweets, fresh or frozen red meat (but not processed meat), among those who reported using polyunsaturated spreads and among moderate alcohol drinkers. These associations were broadly similar for deaths from ischaemic heart disease (IHD), cancer and all other causes combined, and were not greatly attenuated by adjusting for potential confounding factors including social class.

Responses to simple questions about nutrition were associated with mortality. These findings must be interpreted with caution since residual confounding by dietary and lifestyle factors may underlie the associations.

To describe an approach for assessing the prevalence of nutrient inadequacy in a group, using daily intake data and the new Estimated Average Requirement (EAR).

Observing the proportion of individuals in a group whose usual intake of a nutrient is below their requirement for the nutrient is not possible in general. We argue that this proportion can be well approximated in many cases by counting, instead, the number of individuals in the group whose intakes are below the EAR for the nutrient.

This is a methodological paper, and thus emphasis is not on analysing specific data sets. For illustration of one of the statistical methods presented herein, we have used the 1989–91 Continuing Survey on Food Intakes by Individuals.

We show that the EAR and a reliable estimate of the usual intake distribution in the group of interest can be used to assess the proportion of individuals in the group whose usual intakes are not meeting their requirements. This approach, while simple, does not perform well in every case. For example, it cannot be used on energy, since intakes and requirements for energy are highly correlated. Similarly, iron in menstruating women presents some difficulties, due to the fact that the distribution of iron requirements in this group is known to be skewed.

The apparently intractable problem of assessing the proportion of individuals in a group whose usual intakes of a nutrient are not meeting their requirements can be solved by comparing usual intakes to the EAR for the nutrient, as long as some conditions are met. These are: (1) intakes and requirements for the nutrient must be independent, (2) the distribution of requirements must be approximately symmetric around its mean, the EAR, and (3) the variance of the distribution of requirements should be smaller than the variance of the usual intake distribution.

The European diet is characterized by a wide variation in every aspect of eating from the timing of meals to the composition of meals. In general, there is a tendency in terms of dietary advice towards lower fat intakes in order to reduce saturated fatty acid intake and to reduce the risk of obesity. Such diets are most successful and yield the most favourable metabolic profile when there is an adequate level of physical activity.

The aim of the present paper was to explore how the composition of dietary fat changes across the EU with low- and high-fat diets and to explore levels of physical activity and attitudes to physical activity across the EU.

The paper draws on data contained in reports and supplements of the Institute of European Food Studies in the EU.

There is a clear trend for southern EU states to have higher MUFA intakes and lower SFA intakes than northern EU states. However, for both geographic regions, the fatty acid composition of dietary fat was similar in groups with lower or higher dietary fat intakes. Physical activity was ranked low by consumers (n = 15,000) for its importance in relation to health and the prevention of weight-gain. Some 47% agreed that their present level of physical activity is sufficient. 78% agreed that being 13 kg heavier would not be detrimental to health and 30% agreed that the main benefit of physical activity was to relieve stress.

(i) The present strategy of lowering dietary fat intake does not alter dietary fat composition and (ii) there is a high level of ignorance among consumers of the benefits of physical activity and the adverse effects of excess body-weight.

To review the current literature on the effects of soy isoflavones, one class of phyto-oestrogens, on cardiovascular diseases, osteoporosis, cancer and climacteric symptoms.

Many study designs were employed in the reports reviewed here, including prospective human trials, observational human studies, animal experiments and in vitro cell studies that explored the protective or preventive effects of soy isoflavones (genistein, daidzein and glycitein alone or mixed).

Diverse settings were employed, depending on study design.

Human subjects, mostly menopausal or postmenopausal, were included, as were animal models and specific cell types.

The findings were: (i) isoflavones plus soy protein together were needed to obtain the highly significant beneficial results on blood lipids and arterial dimensions; (ii) isoflavone treatments alone at high doses (relative to above) consistently improved bone parameters in rodent ovariectomized models, but not in humans or primates; (iii) isoflavones were not consistent in exerting positive effects regarding the prevention or treatment of cancers of the mammary glands, uterus and colon; and (iv) the effects of isoflavones on climacteric symptoms were not clear-cut.

The promise of soy isoflavones reducing chronic disease risk seems to be non-uniform, with the most conclusive benefits occurring in the prevention of cardiovascular diseases, but other organ systems, such as skeletal and reproductive tissues, may also benefit from the consumption of soy and soy-derived products.