Secular trends of weight, height and obesity in cohorts of young Portuguese males in the District of Lisbon: 1960-1990

The International Growth Standard for Children and Adolescents Project: Environmental Influences on Preadolescent and Adolescent Growth in Weight and Height

This review has two aims. The first is to identify important environmental influences on the growth of children aged 1 to 9 years and of adolescents, defined as those aged 10 to 19 years. The second is to identify possible environmentally based criteria for the selection of individuals and populations for data collection in the development of an international growth reference for these age ranges. There are many common environmental influences on the growth of children between the ages of 1 and 19 years; the examination and description of these forms the main body of this review. Subsequently, environmental factors influencing adolescent growth only are considered. In both cases, possible selection criteria are put forward. The most important inclusion criteria for both preadolescence and adolescence are good nutrition, lack of infection, and socioeconomic status that does not constrain growth. Additionally, low birthweight, catch-up growth, breastfeeding, and early adiposity rebound have impacts on growth and/or body composition into puberty. Exclusion of children born at low birth and/or experiencing catch-up growth could be most realistically operationalized if populations in which secular trends in growth were either completed or minimal were selected. Although an effect of hypoxia on child and adolescent growth, independent of nutrition, is small at most, many high-altitude populations have high prevalances of low birthweight and should be excluded on this basis. Since all populations are exposed to pollutants, contaminants, and toxicants in varying degrees, they cannot be realistically excluded from the sample frame. However, it may be desirable to exclude populations that are habitually exposed to extremely high levels of environmental pollution, including air pollution, and those living in close proximity to toxic waste. It is impossible to exclude populations and individuals on the basis of their exposure to aflatoxin contamination of food. However, exclusion on the basis of low socioeconomic status or poverty may well act as a proxy for this. There are a small number of populations that show extreme patterns of growth in body size and proportion in preadolescence and adolescence, and these should be excluded from the sample frame.

Overweight trends among Polish schoolchildren before and after the transition from communism to capitalism

This study aims to reveal the secular trends in body mass index (BMI) and the prevalence of overweight and obesity among Polish schoolchildren between the years 1966-2012, during which intense socio-political changes took place. Four surveys were conducted in several districts of Poland looking at 69,746 schoolchildren aged 7-18. Significant increase in mean BMI as well as in the prevalence of overweight and obesity was observed. During this time the highest increase in both mean BMI and excess weight was observed between 1988 and 2012, i.e. after the political transformation, resulting in the improvement of living conditions. However, with respect to girls in late adolescence, between these years, the mean BMI as well as the prevalence of overweight were leveling off, while the percentage of boys with excess body fat in the same developmental category significantly increased in 2012. In the years 1966-1978 and 1978-1988 the pattern of changes in the prevalence of overweight and obesity reflected the social and economic circumstances, i.e. temporary economic improvements, or deepening political crises and food shortage. In conclusion, the weight status of schoolchildren strongly reflects socio-political changes that took place in Poland, as well as in most of the Central European countries in the last half century.

Trends of BMI and prevalence of overweight and obesity in Portugal (1995-2005): a systematic review

OBJECTIVE

Locale-specific data on BMI and overweight/obesity are necessary to understand how the obesity epidemic is evolving in each setting. We aimed to describe the temporal trends of mean BMI and prevalences of overweight/obesity in studies that evaluated Portuguese adults and older people.

DESIGN

Systematic review, conducted via a PubMed search up to January 2011 and independent reference screening and data extraction. Twenty-one eligible studies were identified. Data were extracted from the published reports and obtained from the authors of seven of the largest studies. Adjusted ecological estimates of mean BMI and prevalences of overweight/obesity were computed by linear regression.

RESULTS

Between 1995 and 2005, when using data obtained from anthropometric measurements, overweight prevalence increased by 3·2 % and 3·5 % and obesity prevalence by 7·4 % and 1·3 % among women and men, respectively, while mean BMI did not vary meaningfully. When using self-reported information, mean BMI increased by 0·8 kg/m2 and 0·9 kg/m2, overweight prevalence by 3·5 % and 3·7 % and obesity prevalence by 5·8 % and 5·5 % among women and men, respectively. Results from the 20-year-old conscripts (1960-2000) showed a marked increase in these outcomes in the last decades.

CONCLUSIONS

Our results show an important increase in overweight/obesity in younger ages. The trends in the indicators derived from self-reported data suggest an increase in awareness of the importance of overweight/obesity among the population.

Age standardization in mapping adult overweight and obesity trends in the WHO European Region

This study aims to improve comparability of available data within the World Health Organization (WHO) European Region taking into account differences related to the aging of the population. Surveys were included if they were conducted on adults aged 25-64 years between 1985 and 2010 in the WHO European Region. Overweight/obesity prevalences were adjusted to the European standard population aged 25-64. Data were entered for each of the 5-year categories between 1981 and 2010. Measured height and weight data were available for males in 16 and females in 24 of the 53 countries. The 50-64-year-olds had higher prevalence of overweight and obesity as compared to the 25-49-year-olds. This pattern occurs in every country, by male and female, in almost all surveys. Age-standardized overweight prevalence was higher among males than females in all countries. Trend data showed increases in most countries. Age-standardized maps were based on self-reported data because of insufficient availability of measured data. Results showed more countries with available data as well as the higher category of obesity in the later surveys. Measured values are needed and age adjustment is important in documenting emerging overweight and obesity trends, independent of demographic changes, in the WHO European Region.

Ten-year trends in overweight and obesity in the adult Portuguese population, 1995 to 2005

BACKGROUND

There is little information regarding the trends in body mass index (BMI) and obesity in the overall Portuguese population, namely if these trends are similar according to educational level. In this study, we assessed the trends in the prevalence of overweight and obesity in the Portuguese population, overall and by educational level.

METHODS

Cross-sectional national health interview surveys conducted in 1995-6 (n = 38,504), 1998-9 (n = 38,688) and 2005-6 (n = 25,348). Data were derived from the population and housing census of 1991 and two geographically-based strata were defined. The sampling unit was the house, and all subjects living in the sampling unit were surveyed. Height and weight were self-reported; the effects of gender, age group and educational level were also assessed by self-reported structured questionnaires. Bivariate comparisons were performed using Chi-square or analysis of variance (ANOVA). Trends in BMI levels were assessed by linear regression analysis, while trends in the prevalence of obesity were assessed by logistic regression.

RESULTS

Mean (±standard deviation) BMI increased from 25.2 ± 4.0 in 1995-6 to 25.7 ± 4.5 kg/m² in 2005-6. Prevalence of overweight remained stable (36.1% in 1995-6 and 36.4% in 2005) while prevalence of obesity increased (11.5% in 1995-6 and 15.1% in 2005-6). Similar findings were observed according to age group. Mean age-adjusted BMI increase (expressed in kg/m²/year and 95% confidence interval) was 0.073 (0.062, 0.084), 0.016 (0.000, 0.031) and 0.073 (0.049, 0.098) in men with primary, secondary and university levels, respectively; the corresponding values in women were 0.085 (0.073, 0.097), 0.052 (0.035, 0.069) and 0.062 (0.038, 0.084). Relative to 1995-6, obesity rates increased by 48%, 41% and 59% in men and by 40%, 75% and 177% in women with primary, secondary and university levels, respectively. The corresponding values for overweight were 6%, 1% and 23% in men and 5%, 7% and 65% in women.

CONCLUSION

Between 1995 and 2005, obesity increased while overweight remained stable in the adult Portuguese population. Although higher rates were found among lesser educated subjects, the strong increase in BMI and obesity levels in highly educated subjects is of concern.

Secular trends in height and weight for healthy Han children aged 0-7 years in China, 1975-2005

OBJECTIVES

To report the secular growth changes of Chinese children aged 0-7 years between 1975 and 2005.

METHODS

Height and weight measurements obtained from four consecutive national surveys were used to analyze the secular trends. Urban-rural difference and regional difference in growth were compared, respectively.

RESULTS

A rapid positive secular trend was observed in China over the last three decades, increased by 5.3 and 5.0 cm in height for urban boys and girls at age 6-7 years, respectively. Urban-rural height difference has continuously reduced, but weight difference has gradually widened after 3-years old which results from the excessive weight increase of urban children, 2.68 kg for rural boys aged 6-7 years but 3.26 kg for urban during the 30 years. Clear regional differences in growth are not narrowing over time. Generally, the growth level in eastern China is higher than central-western, successively higher than southern.

CONCLUSIONS

The rapid positive secular trends will still continue with the rapid socio-economic development in China. Urban-rural height difference will further narrow. Currently no sufficient evidence indicates that growth difference in inter-city has reduced. Weight increases rapidly for urban children, which does not match with height.

Trends in weights, heights, BMI and comparison of their differences in urban and rural areas for Iranian children and adolescents 2-18-year-old between 1990-1991 and 1999

BACKGROUND

Secular trends in height and weight are interesting because in middle- and low-income countries they are a marker for changes in population health. The present study aims to evaluate the secular trend in height and weight and body mass index (BMI) of Iranian children and adolescents aged 2-18 years old between 1990-1991 and 1999 and compare the magnitude of urban-rural differences during this period for the first time in an Asian country.

METHODS

Data from two national health surveys in 1990-1991 and 1999, of 22,349 and 25,196 weight and height measures of Iranian children and adolescents were used to study the trend and compare its difference in urban and rural children. Logarithmic transformation of weight, height and BMI was modelled as a polynomial in age for urban and rural boys and girls in each survey separately. The trend in urban and rural growth indexes (weight, height and BMI) and also the comparisons of urban-rural differences between two national surveys were tested in logarithmic scale using a weighted form of Z statistic for comparison of two means adjusted for age groups.

RESULTS

Urban and rural boys and girls became taller and heavier (P≤ 0.02) with no change of BMI (P > 0.05) during the period. There was not any significant difference between the magnitudes of urban-rural difference between two surveys (P≥ 0.61).

CONCLUSION

Although generally positive weight and height trend was observed among urban and rural residents, the magnitude of their differences was not changed.

Incidence and risk factors for the metabolic syndrome in an urban South European population

OBJECTIVE

To estimate the incidence of the metabolic syndrome in a Portuguese sample and to evaluate its specific risk factors.

METHODS

During a follow-up evaluation (May 2005-September 2008) of a Portuguese community cohort, 1377 participants were eligible for this study. Data on social, demographic, personal and family medical history and behavioral characteristics (including alcohol consumption and smoking habits) were collected. The metabolic syndrome was defined according to the AHA/NHLBI criteria Crude incidence rates were calculated for the total sample, by sex and age classes, and Poisson generalized linear models were used, with the default log link and offset in the variable time.

RESULTS

The incidence rate of metabolic syndrome in this population was 47.2 /1000 person-years (95% CI: 41.2-53.9), similar in females and in males. The incidence of metabolic syndrome increased with age and in less educated participants. No significant association was observed between the occurrence of metabolic syndrome and the behavioral characteristics evaluated. High waist circumference presented the strongest association with the occurrence of the metabolic syndrome, even after adjustment for other confounders (IRR=1.68; 95% CI: 1.47-1.93).

CONCLUSION

Older and less educated participants had a higher syndrome incidence. In this population, central obesity was the strongest predictor of metabolic syndrome.

Estimation of secular trends in adult height, and childhood socioeconomic circumstances in three Eastern European populations

The objective of these analyses was to estimate the strength and direction of secular trends in adult height and childhood socioeconomic circumstances in eight towns in three Eastern European countries in the mid-20th century, and to assess the extent to which childhood conditions might explain the height differences. We used cross-sectional data from the baseline survey of the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study, conducted in 2002-2005. The study examined 24,012 men and women born between 1933 and 1957, randomly selected from the general populations of Novosibirsk (Russia), Krakow (Poland) and six towns of the Czech Republic. To allow for age-related height loss we estimated maximum attained height. Parental education and household item ownership at age 10 were used as markers of childhood socioeconomic conditions. In all 5-year birth cohorts, Novosibirsk men and women were shortest. There were positive and statistically significant secular trends in childhood conditions and in maximum adult height. Adjustment for childhood conditions explained about one third of the trend in height. There appeared to be a small reduction in height of persons born during the Second World War which was, however, only significant in Novosibirsk. These results suggest that secular trends in height mirror, but are not wholly explained by, trends in socioeconomic circumstances in early life.

Secular trends in height and weight among children and adolescents of the Seychelles, 1956-2006

BACKGROUND

Height of individuals has long been considered as a significant index of nutrition and health of a population; still, there is little information regarding the trends of height and weight among developing or transitional countries. We assessed the secular trends in height and weight in children of the Seychelles, a rapidly developing island state in the Indian Ocean (African region).

METHODS

Height and weight were measured in all students of all schools in four selected school grades (kindergarten, 4th, 7th and 10th grades) for the periods 1998-9 (6391 children) and 2005-6 (8582 children). Data for 1956-7 was extracted from a previously published report.

RESULTS

At age 15.5 years, boys/girls were on average 10/13 cm taller and 15/9 kg heavier in 2005-6 than in 1956-7. Height increased in boys/girls by 1.62/0.93 cm/decade between 1956-7 and 1998-9 and by 1.14/1.82 cm/decade between 1998-9 and 2005-6. For weight, the linear increase in boys/girls was 1.38/1.10 kg/decade between 1956-7 and 1998-9 and 2.21/2.50 kg/decade between 1998-9 and 2005-6. Overall, the relative increase in weight between 1956-7 and 2005-6 was 5-fold higher than the relative increase in height.

CONCLUSION

Height and weight increased markedly over time in children aged <16 years in the Seychelles, consistent with large changes in socio-economic and nutritional indicators in the considered 50-year interval. The markedly steeper increase in weight than height over time is consistent with an epidemic of overweight and obesity.

Out-of-pocket health care expenditures due to excess of body weight in Portugal

The prevalence for excessive weight has also been increasing dramatically in Portugal over the last decades. The consequences for families as well as for the publicly funded Portuguese health care system are a matter of policy interest. This paper uses an econometric model to compute the fraction of the national out-of-pocket health care expenditures attributable to overweight and obesity among Portuguese adults. Given that public health care system pays for a substantial share of the national health care expenditures, the estimated the out-of-pocket expenditures is only a share of the total expenditures. Per-capita expenditures and the burden that obesity and overweight impose on families are also estimated. Two waves of the Portuguese National Health Survey (NHS), namely; 1995/1996 and 1998/1999 are considered. The results suggest that out-of-pocket expenditures due to excess weight have increased sharply during these 3 years. The two-part model estimates suggest that the obese and overweight are more likely to incur out-of-pocket health care expenditures but, in the restricted sample of those that incur expenditures, there is weak or no evidence that the obese or overweight spend, on average, more than those of normal weight. Overall, it is estimated that in 1995/1996, more than 1.8% out-of-pocket health care expenditures were attributable to obesity and 2% to overweight (although not statistically significant). The estimated percentages are over 2.9% for obesity and 4% for overweight in 1998/1999. Combined, the estimated attributable percentage of national out-of-pocket expenditures due to excess weight was 3.8% in 1995/1996 and 6.9% in 1998/1999. Per-capita expenditures due to obesity or overweight are small, on average, in absolute terms, but they can be a significant cost for low income families. With respect to public policy concerns, the results suggest that measures which only slightly increase the out-of-pocket health care expenditures of being obese (overweight) are likely to be inefficient.

Gender, socio-economic status and metabolic syndrome in middle-aged and old adults

Background

Studies that addressed social and economic determinants of cardiovascular diseases, consistently showed an increase prevalence of the individual features of metabolic syndrome in the lower socio-economic strata. Thus, this study aimed to evaluate the association between social class and metabolic syndrome in a sample of urban middle-aged and old Portuguese adults.

Methods

We evaluated 1962 subjects (1207 women and 755 men) aged 40 or more years. Marital status, education, occupation, menarche age and height distribution were used as socioeconomic indicators. Metabolic syndrome was defined according to the ATP III, by the presence of at least three of the following characteristics: waist circumference >102 cm in men and >88 cm in women; triglycerides ≥ 150 mg/dl; HDL cholesterol <40 mg/dl in men and <50 mg/dl in women; blood pressure ≥ 130/85 mm Hg; and fasting glucose ≥ 110 mg/dl. Proportions were compared using the chi square test or Fisher's exact test. Odds ratios (OR) and 95% confidence intervals (95% CI) were computed using unconditional logistic regression to estimate the magnitude of the associations.

Results

Metabolic syndrome was significantly more frequent in females (24.9 vs. 17.4, p < 0.001). In females, the odds favoring metabolic syndrome significantly increased with age and in unfavorable social class as described by occupation, and decreased with education level. In males, metabolic syndrome was significantly more frequent in the 60–69 years age class (OR = 1.82; 95%CI: 1.02–3.26) when compared to those in the 40–49 years age class. Concerning other socioeconomic indicators no significant associations were found.

Conclusion

This study showed that gender influenced the association of socio-economic status indicators with metabolic syndrome. Females in lower social classes, as defined by education and occupational classification, more frequently presented metabolic syndrome, no such association was found in males.

Trends in overweight and obesity in Portuguese conscripts from 1986 to 2000 in relation to place of residence and educational level

OBJECTIVE

The aim of this study was to analyse changes in the prevalence of overweight and obesity between 1986 and 2000 in Portuguese conscripts, and to examine the role of place of residence and educational level.

STUDY DESIGN

Cross-sectional study.

METHODS

Data sets from the cross-sectional annual surveys of all 18-year-old Portuguese males born between 1966 and 1981 and examined between 1986 and 2000 (850 081 subjects) were used in this study. Height and weight were measured and body mass index was calculated. Data on educational level (4, 6, 9, 11 and 12+ years) and residence (urban, semi-urban and rural) were collected.

RESULTS

The prevalence of overweight increased from 10.5% in 1986 to 21.3% in 2000, and the prevalence of obesity increased from 0.9% to 4.2% in the same period (P<0.001). After adjustment for year of examination, the odds ratio (OR) for being overweight increased with educational level (reference 4-6 years: 1.19; 9 years: 1.30; 11 years: 1.47; 12+ years: 2.41) and place of residence (reference urban-semi-urban: 1.04; rural: 1.06). The prevalence of obesity increased with educational level (reference 4-6 years: 1.27; 9 years: 1.79; 11 years: 1.83; 12+ years: 2.66) and decreased with place of residence, i.e. those who lived in rural areas had a lower risk of becoming obese (OR: 0.94).

CONCLUSIONS

Despite the low prevalence of obesity in young males in Portugal compared with other European countries, the sharp increase in recent years indicates that public health strategies are needed to prevent obesity.

The relationship between body mass index and educational level in young Portuguese males: 1995 and 1999 cohorts

INTRODUCTION

Over the last decades, a progressive increase in height and weight has been observed throughout Europe. Increase in weight has been more marked however, with a resulting increase in overweight and obesity prevalence. RESULTS published have analyzed the relationship between body mass index (BMI) and educational level. Most studies indicate an inverse relationship between BMI and educational level in developed countries.

OBJECTIVE

This study's main objective was to evaluate the relationship between BMI and educational level (years of schooling) in young Portuguese males in 1995 and 1999.

METHODS

Transverse study of data (BMI and years of schooling) from the military inspection records of virtually the entire Portuguese male population with an average age of 20 years, examined in 1995 and 1999, totaling 81 363 and 71 254, respectively. Four classes of BMI (<20, 20-24.9, 25-29.9 and > or =30 kg/m2) and four schooling levels (<5, 5-9, 10-12, and >12 years) were considered. We applied the chi2 test for associations between BMI and educational level and the odds ratio to quantify categorical variables. The significance level was 5%.

RESULTS

In 1995, 15.2% were overweight (BMI> or =25 years), increasing to 20.8% in 1999. The percentage of obesity (BMI> or =30 years) was 1.4% in 1995 and 2.2% in 1999. The percentage of overweight and obesity increased directly in line with the increase in educational level, both in 1995 and 1999. In 1995, the percentage of subjects with obesity according to years of schooling was as follows: <5 years--1.4%; 5-9 years--1.4%; 10-12 years--1.5% and >12 years--1.7%. In 1999, the results were as follows: <5 years--1.4%; 5-9 years--2.2%; 10-12 years--2.8% and >12 years--3.2%.

CONCLUSIONS

We can conclude that the prevalence of overweight and obesity in young male Portuguese increased in the last decade and that, unlike most developed countries, the higher the level of education, the greater the percentage of overweight and obesity, both in 1995 and 1999.

Changes in the BMI of Polish conscripts between 1965 and 2001: secular and socio-occupational variation

OBJECTIVE

To describe changes in the body mass index (BMI) of nationally representative samples of young adult Polish males between 1965 and 2001, and to investigate variation in the incidence of underweight, overweight and obesity between 1965 and 2001 in the young adult males in the context of the socio-political transformation that occurred in Poland since 1989.

SUBJECTS

Four 10% nationwide random samples of 29-year-old Polish conscripts examined in 1965, 1986, 1995 and 2001. The conscripts were divided into four socio-occupational groups based on paternal education, occupation and degree of urbanization.

MEASUREMENTS

Height, weight and BMI (weight (kg)/height (m2)).

RESULTS

The proportion of overweight and underweight young adult males in the population increased between 1965 and 2001. The fraction of underweight decreased only among sons of farmers and entrepreneurs between 1986 and 1995 and then increased in all socio-occupational groups between 1995 and 2001. On the other hand, the proportion of overweight young adults gradually increased in all groups between 1965 and 2001.

CONCLUSION

Socio-occupational position of the family is an important factor influencing underweight and overweight in young adult males. This factor apparently operates through a differential distribution of income, which influences components of lifestyle most likely associated with level of habitual physical activity and/or diet.

Trends in overweight and obesity in Portugal: the National Health Surveys 1995-6 and 1998-9

OBJECTIVE

To assess overweight and obesity trends in the Portuguese population.

RESEARCH METHODS AND PROCEDURES

National Health Surveys, conducted in 1995-6 (17,989 men; 20,249 women) and 1998-9 (17,923 men; 20,302 women), were used.

RESULTS

In men, the prevalence of overweight and obesity increased from 39.9% (95% CI: 39.2 to 40.6) and 10.3% (95% CI: 9.9 to 10.7), respectively, in 1995-6, to 42.5% (95% CI: 41.8 to 43.2) and 11.5% (95% CI: 11.0 to 12.0), respectively, in 1998-9. In women, prevalence of obesity increased from 12.7% (95% CI: 12.2 to 13.2) in 1995-6 to 14.2% (95% CI: 13.7 to 14.6) in 1998-9, whereas the prevalence of overweight remained stable: 32.2% (95% CI: 31.6 to 32.9) in 1995-6 and 32.3% (95% CI: 31.6 to 32.9) in 1998-9. In men, prevalence of overweight and obesity were higher among former smokers and educational group of 6 to 12 years, and prevalence of obesity was higher in the Lisbon region. In women, prevalence of overweight and obesity were higher among never smokers, and prevalence of obesity was higher among educational group of -6 years. Prevalence of obesity was higher in the Alentejo region, and overweight was higher in the Center region. Finally, prevalence of obesity increased in both sexes for all strata studied (age, smoking status, educational level, and geographic region), whereas prevalence of overweight increased only in men.

DISCUSSION

In Portugal, overweight and obesity levels are related to sociodemographic factors; the increase in obesity levels stresses the need for preventive measures.

The effect of the economic transition on the body mass index of conscripts in Poland

The political and socio-economic transition initiated in Poland in the late 1980s is still continuing and has affected all social classes as well as all spheres of daily life of the people. The impact of this change on nutrition and health is examined here, by comparing the body mass index (BMI) of a 10% nationally representative sample of male conscripts aged 19 years (18.50-19.49), in 1986 (n = 26,396), 1995 (n = 22,612), and 2001 (n = 26,178). Mean BMI of young men did not change between 1986 and 1995, but then increased slightly from 22.0 to 22.3 between 1995 and 2001. There was also a significant and continuous increase in the variation of BMI in all social strata across the entire period 1986-2001. This effect is attributed to economic modernisation that has allowed increased diversity of life styles across occupational groups and between families. Sibship size was more important than socio-economic status in explaining variation in BMI after the political changes in 1990. The BMI-enhancing effect of small sibship size is attributed to nutritional intake, and to changes in food availability across the period under study.

Prevalence and determinants of obesity in an urban sample of Portuguese adults

OBJECTIVE

To evaluate the prevalence and the determinants of obesity, and the associated cardiovascular risk factors in a random sample of non-institutionalised adults.

DESIGN

Cross-sectional study.

SUBJECTS

A random sample of 1436 habitants of Porto (873 women and 563 men) aged 18-90 years.

MEASUREMENTS

All participants answered a structured questionnaire comprising information on social, demographic, behavioural and clinical aspects. Anthropometric measures, blood pressure and fasting blood samples were obtained. Diet was assessed using a semi-quantitative food-frequency questionnaire, and physical activity was evaluated using a questionnaire exploring all professional, domestic and leisure-time activities. When the body mass index was > or =30 kg/m2, the subject was considered as 'obese'. Proportions were age adjusted for the European population. Odds ratios and 95% confidence intervals were computed using unconditional logistic regression.

RESULTS

The prevalence of obesity was significantly higher in women (26.1%) than men (13.9%). Regardless of gender, obesity increased with age, decreased with education, and was more frequent in married blue-collar workers and unemployed subjects. Smoking was more prevalent in subjects of normal weight, and a higher proportion of those reporting no regular exercise were obese. In men, obesity prevalence increased with increasing quartiles of energy intake, but no such changes were found in women. Compared with subjects of normal weight, obese men showed a significantly higher prevalence of hypertension (53.3 vs 26.1%) and hypertriglyceridaemia (23.4 vs 9.0%). Also, hypertension (43.7 vs 30.7%), diabetes (7.6 vs 2.7%), hypertriglyceridaemia (27.1 vs 5.0%), and abnormal low-density lipoprotein (30.4 vs 21.4%) and high-density lipoprotein cholesterol concentration (15.0 vs 5.3%) were more frequent in obese women.

CONCLUSION

Obesity is a major public health issue in urban Portuguese populations, and obese individuals have many features of metabolic syndrome. Education and relative deprivation are modifiable factors that are significantly associated with obesity. However, no clear-cut relationship was found between physical activity and energy intake.

Height of young men

We analysed the height of young men in Belgium, using 613 257 records of medical examinations made prior to their conscription into the army (about 68% of the male population concerned). All analyses showed very significant associations. Height differed according to the region (-1.24cm in Wallonia, French-speaking and poorer) compared to Flanders (Dutch-speaking and richer), when "age-class" and year are taken into account. The smallest men lived in Hainaut (a deprived area), the tallest ones in Walloon Brabant (wealthy green suburbs of the capital). Height increased across time (+1.11cm, 1978-1990) and with "age-class" (+2.66cm, 18-26years), controlling for other factors. The increase in Brussels stops in 1983, probably due to other socio-demographic evolutions.

Pubertal height gain: male-female and interpopulation comparisons

Data are not available as to the exact age of the start of the pubertal growth spurt (or age at its conclusion) in various populations. As an initial approach, contribution of the pubertal gain to overall height was examined, using age 9 as the start of puberty in girls and age 11 in boys. Data were analyzed from 11 reports (single assays on five populations, two studies on a group analyzed 30 years apart, and four studies of a population spread over 31 years. Using the percent contribution to overall height, pubertal growth showed a close agreement between the populations as well as between male and female values (overall p < 0.003). Results for both sexes clustered around a narrow range. Pubertal growth for the 50th percentile, expressed as a percent contribution to overall height, may approach a biologic invariant. The value of percent contribution of pubertal growth to final height, did not show a secular trend.

Increasing obesity among male workers in Japan: 1992-1997

OBJECTIVE

To examine changes in the Body Mass Index (BMI) and in the prevalence of obesity among male Japanese workers after five years.

DESIGN

Follow-up study, based on data from annual health checkups performed at workplaces.

SUBJECTS AND METHODS

We had access to the data for a total of 63,951 male workers aged 20 through 54 years in 1992 who were examined in both 1992 and 1997. In quinquennial cohorts, we compared the findings for mean BMI and the prevalence of obesity in 1992 with the findings in 1997.

RESULTS

Between 1992 and 1997, in all cohorts the mean BMI increased significantly. For each adjacent cohort pair the mean BMI value in 1997 was significantly higher than in 1992. In 1992, 21.3% of all subjects were obese, increasing by 3.4% after five years to 24.7% in 1997. In the younger 1968-1972 and 1963-1967 cohorts the prevalence of obesity increased by 6.3% during five years. The significant increase in the obesity prevalence was observed from 1992 to 1997 for each age-adjusted cohort.

CONCLUSIONS

These results suggest a substantial increase in obesity among male Japanese workers. The notable increase in the prevalence of obesity among young male adults and the general trend toward widespread obesity during five years signal an increasing risk of lifestyle-related diseases.

Parental education, body mass index and prevalence of obesity among 14-year-old boys between 1987 and 1997 in Wrocław, Poland

The main aim of this study was to examine changes in relative weight and prevalence of obesity across a ten-year period among 14-year-old boys according to parental education level. Data from two surveys, carried out in 1987 and 1997, of boys attending the 7th grade of primary schools in Wrocław were used in the analysis. The heights and weights of 3165 boys aged 14 years selected from cohort of 6969 7th and 8th grade boys from all primary schools of the city Wrocław were used. The data of the second sample of 14-year-old boys (n = 1014) were obtained from a health examination study carried out in the Silesian Centre for Preventive Medicine, 'DOLMED', in Wrocław in 1997. All boys attended the 7th grade of 34 randomly selected primary schools from a total of 129 schools in the city of Wrocław. Social status was assessed on the basis of parental education level scored to four categories: university, secondary school, trade school, and elementary school. The prevalence of overweight and obesity was defined as the percentage of children above the 85th and 95th percentiles of the body mass index (BMI), the means of which were 21.27 and 23.75 kg/m2 respectively. Prevalence of overweight among boys is slightly lower in the 1997 sample, whereas the prevalence of obesity shows the opposite trend and is higher by more than one percent in comparison with the 1987 sample. Similar trends of declining medians and increasing variance are observed in all educational groups. The differences in medians between the two samples within educational groups did not achieve statistical significance for the groups with parents with education at elementary level and fathers with university education. There is a trend toward increasing prevalence of obesity across the decade considered, according to father's education level. With respect to mother's education levels, the most dramatic changes in BMI and obesity occurred in the elementary education group, where the percentage of obese subjects increased more than twofold. A significant increase is also observed in the group with parents attaining university education.

Variation in the body mass index among young adult Polish males between 1965 and 1995

OBJECTIVE

To investigate whether the incidence of overweight and underweight individuals among young adults showed inter-generation changes or social-class differences in Poland between the mid-1960s and mid-1990s.

DESIGN

Comparisons of variation in the body mass index and in height among 19-y-old Polish males drawn from three successive birth cohorts.

SUBJECTS

Three 10% nation wide random samples of 19-y-old Polish conscripts, examined in 1965, 1986 and 1995, a total of ca. 80,000 individuals.

MEASUREMENTS

Body mass index (weight (kg)/height (m2) and height (m). PRINCIPAL RESULT: There has been during the three decades between the mid-1960s and mid-1990s a gradual and significant increase in the proportion of both 'overweight' and of 'underweight' young males, as well as of the very tall and very short ones in the population.

CONCLUSION

The above finding seems intriguing. It may suggest that certain elements of individual lifestyles, those influencing the leanness vs fatness variation among young adults, as well as those affecting growth in height, have tended to become in Poland increasingly diversified in terms of between-family differences, irrespective of social-class differences and of the general nationwide changes in living standards.