Short Communication - Continued increase in prevalence of obesity in Danish young men

Development of physical fitness performance in young Swiss men from 2006 to 2015

From 1980 to 2000, physical fitness decreased and body mass index (BMI) increased in the population of many industrialized countries. Little is known about these trends after the year 2000. This study aimed to investigate physical fitness performance, physical activity (PA) behavior, and BMI of young, male Swiss adults between 2006 and 2015. For this purpose, results from the Swiss Armed Forces mandatory recruitment were used. A total of 306 746 male conscripts provided complete fitness test data, mean ± SD (range from 5th to 95th percentile): 20 ± 1 (18‐21) years, 178 ± 7 (168‐189) cm; 74 ± 13 (58‐97) kg, predicted maximal oxygen consumption of 49.9 ± 4.6 (41.8‐56.9) mL/kg/min (Conconi test), 125 ± 58 (43‐232) seconds in trunk muscle strength test (prone bridge), 2.31 ± 0.24 (1.90‐2.66) m in standing long jump, 6.46 ± 0.73 (5.30‐7.70) m in seated shot put (2 kg medical‐ball shot) and 45.6 ± 12.2 (29.9‐66.7) seconds in one‐leg standing test (sum of both legs; eyes closed after 10 seconds and head tilted back after 20 seconds). In the investigated population, 73.8% fulfilled basic PA recommendations, 46.2% were classified as regularly vigorously active. Performances in aerobic endurance and muscle power did not show secular changes over time. However, core stability performance and PA behavior increased, while balance ability decreased over this 10‐year period. Average BMI increased by 2.0% between 2006 and 2010 and did not change thereafter. Male Swiss adults are at least as physically fit as they were a decade ago. The secular trends of decreasing physical performances and increasing BMI have stopped, and self‐reported sport participation and leisure time PA have been increased in the observed population over the last 10 years.

Physical Fitness in Young Men between 1975 and 2015 with a Focus on the Years 2005-2015

PURPOSE

The purpose of the present study was to investigate changes in physical fitness and anthropometry of young men entering the military service in Finland during the years 1975-2015.

METHODS

The study included the fitness test results of 627,142 healthy young male conscripts (age 19.1 ± 0.4 yr). Data included results of aerobic capacity, muscle fitness tests, and anthropometric characteristics.

RESULTS

The results show that the increase in mean body mass of young men has slowed down during the last 10 yr. However, the total increase in body mass was 6.8 kg (8.8%, P ≤ 0.001) between 1993 and 2015. The mean distance achieved in the 12-min running test decreased by 337 m (12.2%, P ≤ 0.001) between the peak in 1980 and 2015. The relative number of conscripts who ran less than 2200 m increased from 3.6% to 25.9% (P ≤ 0.001) between 1980 and 2015, and the proportion who ran more than 3000 m decreased from 25.1% to 6.5% (P ≤ 0.001). The relative number of conscripts who achieved an excellent or good muscle fitness index decreased from 66.8% to 40.1% (P ≤ 0.001) between 1992 and 2000, and remained unchanged between 2000 and 2010. However, the proportion who achieved a poor muscle fitness index increased from 8.1% to 31.4% (P ≤ 0.001) between 1992 and 2010.

DISCUSSION

The present study shows that the increase in mean body mass of young male conscripts has slowed down during the last 10 yr. However, their aerobic capacity has still decreased during recent decades. In addition, the proportion of conscripts with poor muscle fitness has increased. From the national defense and health perspective, more initiatives are needed to encourage young men to increase their level of daily physical activity to be fit and ready for operations.

Body mass index and cognitive function: birth cohort effects in young men

OBJECTIVE

Body mass index (BMI) and intelligence quotient (IQ) are associated. We examined whether this association varied by birth cohort.

METHODS

Among 37,414 Danish conscripts, the association between BMI and IQ overall and by birth cohort was examined. IQ was measured by the Børge Prien's Prøve (BPP) group intelligence test score.

RESULTS

Compared with men of normal BMI, mean differences (95% CI [confidence interval]) in BPP score were -0.6 (-1.1;-0.1) for underweight men; -0.8 (-1.1;-0.5) for overweight men; and -2.0 (-2.4;-1.5) for men with obesity. Crude prevalence ratios (95% CI) for low cognitive scores associated with obesity were, respectively, 1.52 (1.24; 1.85), 1.64 (1.32; 2.04), 1.56 (1.38; 1.76), and 1.35 (1.18; 1.54) among men born in 1955, 1965-1969, 1970-1979, and 1980-1984. Confounding by familial BMI or IQ could not be controlled.

CONCLUSIONS

The association between BMI and IQ is subject to secular trends.

Does prenatal exposure to vitamin D-fortified margarine and milk alter birth weight? A societal experiment

The present study examined whether exposure to vitamin D from fortified margarine and milk during prenatal life influenced mean birth weight and the risk of high or low birth weight. The study was based on the Danish vitamin D fortification programme, which was a societal intervention with mandatory fortification of margarine during 1961-1985 and voluntary fortification of low-fat milk between 1972 and 1976. The influence of prenatal vitamin D exposure on birth weight was investigated among 51 883 Danish children, by comparing birth weight among individuals born during 2 years before or after the initiation and termination of vitamin D fortification programmes. In total, four sets of analyses were performed. Information on birth weight was available in the Copenhagen School Health Record Register for all school children in Copenhagen. The mean birth weight was lower among the exposed than non-exposed children during all study periods (milk initiation - 20·3 (95 % CI - 39·2, - 1·4) g; milk termination - 25·9 (95 % CI - 46·0, - 5·7) g; margarine termination - 45·7 (95 % CI - 66·6, - 24·8) g), except during the period around the initiation of margarine fortification, where exposed children were heavier than non-exposed children (margarine initiation 27·4 (95 % CI 10·8, 44·0) g). No differences in the odds of high (>4000 g) or low ( < 2500 g) birth weight were observed between the children exposed and non-exposed to vitamin D fortification prenatally. Prenatal exposure to vitamin D from fortified margarine and milk altered birth weight, but the effect was small and inconsistent, reaching the conclusion that vitamin D fortification seems to be clinically irrelevant in relation to fetal growth.

Cognitive test scores in young men and subsequent risk of type 2 diabetes, cardiovascular morbidity, and death

BACKGROUND

The association between cognitive scores in young adulthood and long-term cardiometabolic risks remains unclear.

METHODS

Using population-based registries, we followed 6502 military conscripts from their 22nd birthday until death, emigration, or 55 years of age. We calculated risks and hazard ratios (HRs) associating quartiles of cognitive scores (very high, high, moderate, and low) with type 2 diabetes, hypertension, myocardial infarction, stroke, venous thromboembolism, and death before age 55 years.

RESULTS

The 33-year risk of the combined outcome was inversely associated with cognitive scores (26% for low and 16% for very high scores). Compared with very high scores, the HR for the combined outcome was 1.20 (95% confidence interval = 1.02, 1.41) for high, 1.43 (1.22, 1.68) for moderate, and 1.67 (1.43, 1.95) for low scores. Similar HRs were observed for individual outcomes.

CONCLUSION

Low cognitive score in young adulthood was a strong predictor for type 2 diabetes, cardiovascular morbidity, and death before 55 years of age.

Trends of body mass index distribution in schoolchildren in Sendai, Japan, 1989-2003

SUMMARY

Accumulating evidence indicates a strong association between obesity and health problems. Childhood obesity increases the risk of adulthood obesity. Although it is reported that the number of obese children in Japan has increased, it is unclear whether the obesity index distribution pattern has changed. To clarify this distribution pattern, we analyzed the changes in the body mass index (BMI) of primary (6th grade, 12 years old) and junior high (3rd year, 15 years old) schoolchildren in the city of Sendai during the period from 1989 to 2003. Our department has accumulated information on the height and body weight of all the schoolchildren in the city of Sendai. BMI was calculated using both the height and body weight data. The change in median BMI for 15 years had a slightly upward trend every year with both gender and school year. Although the BMI distribution showed that there was little or no change over time in the lower (10th and 25th) percentiles, the increases in the 75th and 90th percentiles were more marked than that in the 50th percentile in primary school children. On the other hand, there was only a small increase in BMI in the 3rd year of junior high school. Our results indicated that the changes in BMI distribution were concentrated at the upper end of the distribution in primary school children. The shifts in the value of high percentiles might be due to effect modification of the corresponding exposure by another environmental exposure or genetic predisposition. It is suggested that the factors causing this change influenced only part of this population, and affected individuals might represent a susceptible subpopulation of the exposed children.:

Population-based trends in overweight and obesity: a comparative study of 2,148,342 Israeli male and female adolescents born 1950-1993

BACKGROUND

The epidemic of obesity has been identified as a major source of morbidity, not just in developed countries but globally, in adults as well as at younger ages.

OBJECTIVE

The aims of this study were to describe trends in obesity and overweight in Israeli adolescents and observe temporal changes and association by risk factors.

METHODS

The research analyzed records of 2,148,342 Jewish adolescents, over a span of 44 years and included data for individual body measurements, place of residence, area of origin and education levels. Body mass index (BMI) was measured by professionals, calculated and categorized as overweight or obesity according to age- and gender-specific BMI curves established in recent years. We processed the data in multinomial logistic regression model and calculated odds ratios for various risk factors.

RESULTS

Obesity and overweight are on the rise for male and female adolescents born from the mid-1960s onwards, and especially for men from the 1980s onwards. Risk factors for male adolescents include lower socioeconomic status, inferior education levels and Western origins (vs. Asian, African or Israeli origins). Risk modifiers for women were similar, except for African origins, which were associated with increased risk rather than decreased risk. Asian and Israeli origins were protective for both genders, and education was more strongly associated with obesity for women.

CONCLUSIONS

We recommend stronger preventive efforts directed at adolescents as a whole, and particularly vulnerable groups with lower education levels and poverty, or those with specific geographical origins. Gender disparities are evident and should be considered in these efforts and in further research.

Obesity in young men, and individual and combined risks of type 2 diabetes, cardiovascular morbidity and death before 55 years of age: a Danish 33-year follow-up study

OBJECTIVES

To examine the association between body mass index (BMI) in young adulthood and cardiovascular risks, including venous thromboembolism, before 55 years of age.

DESIGN

Cohort study using population-based medical databases.

SETTING

Outcomes registered from all hospitals in Denmark from 1977 onwards.

PARTICIPANTS

6502 men born in 1955 and eligible for conscription in Northern Denmark.

MAIN OUTCOME MEASURES

Follow-up began at participants' 22nd birthday and continued until death, emigration or 55 years of age, whichever came first. Using regression analyses, we calculated the risks and HRs, adjusting for cognitive test score and years of education.

RESULTS

48% of all obese young men (BMI ≥30 kg/m(2)) were either diagnosed with type 2 diabetes, hypertension, myocardial infarction, stroke or venous thromboembolism or died before reaching 55 years of age. Comparing obese men with normal weight men (BMI 18.5 to <25.0 kg/m(2)), the risk difference for any outcome was 28% (95% CI 19% to 38%) and the HR was 3.0 (95% CI 2.3 to 4.0). Compared with normal weight, obesity was associated with an event rate that was increased more than eightfold for type 2 diabetes, fourfold for venous thromboembolism and twofold for hypertension, myocardial infarction and death.

CONCLUSIONS

In this cohort of young men, obesity was strongly associated with adverse cardiometabolic events before 55 years of age, including venous thromboembolism. Compared with those of normal weight, young obese men had an absolute risk increase for type 2 diabetes, cardiovascular morbidity or premature death of almost 30%.

Lifelong doubling of mortality in men entering adult life as obese

BACKGROUND

The association between obesity in adults and excess morbidity and mortality is well established, but the impact of being obese in early adulthood on health throughout adult life needs elucidation. We investigated the all-cause mortality until 80 years of age in men starting adult life as obese.

METHODS

Among 362,200 Danish young men, examined for military service between 1943 and 1977, all obese (defined as body mass index (BMI ≥ 31.0 kg m(-2)), and, as controls, a random 1% sample of the remaining population were identified. A total of 1862 obese, corresponding to all men above the 99.5 percentile in this population, and 3476 controls were included, at a median age of 19 years (range: 18-25 years of age). They were followed until 2007 and Cox regression models were used to estimate the mortality in the obese relative to the controls. In addition, two reference groups were used: normal weight men (BMI: 18.5-24.9 kg m(-2)) and the men with the lowest mortality in this cohort (BMI: 22.0-24.9 kg m(-2)).

RESULTS

During the 65 years of follow-up, 1191 men died. At all ages from 18 to 80 years, the mortality in the obese was twice that of the controls (hazard ratio (HR): 2.10; 95% confidence interval (CI): 1.84-2.39). The median survival proportion (0.5) was reached about 8 years earlier in the obese than in either of the reference groups. Relative to the normal weight and men with the lowest mortality HRs of 2.14 (95% CI: 1.86-2.45) and 2.38 (95% CI: 2.00-2.85), respectively, were estimated for the obese. Neither year of birth nor education significantly influenced the excess mortality.

CONCLUSION

Men entering adult life as obese experience a lifelong doubling of mortality, a finding that strongly supports the continued need to avoid beginning adult life as obese.

Physical activity and body composition changes during military service

PURPOSE

To examine how body composition changes in different body mass index (BMI) categories among young Finnish men during military service, which is associated with marked changes in diet and physical activity. In addition, this study examined how reported previous physical activity affected the body composition changes.

METHODS

Altogether 1003 men (19 yr) were followed throughout their military service (6-12 months). Height, weight, BMI, waist circumference, and waist-to-hip ratio (WHR) were recorded. Previous physical activity was assessed at the beginning of the service by a questionnaire. Body composition was measured by bioelectrical impedance assessments (BIA) at the beginning and at the end of the service. The measured parameters were fat mass (FM), fat percentage (fat %), fat-free mass (FFM), visceral fat area (VFA), lean body mass (LBM), and skeletal muscle mass (SMM).

RESULTS

On average, military training decreased weight by 0.7%, FM by 9.7%, fat % by 6.6%, and VFA by 43.4%. FFM increased by 1.3%, LBM by 1.2%, and SMM by 1.7%. The group of underweight and normal-weight men gained weight, FM, and FFM, whereas overweight and obese men lost weight and FM and gained FFM. FM was most reduced in the groups of overweight (20.8%) and obese (24.9%) men. The amount of VFA was reduced in all BMI groups (38%-44%). Among overweight men who reported being inactive previous to the military service, more beneficial changes in body composition were observed compared with those who reported being physically active.

CONCLUSIONS

The lifestyle changes associated with military service markedly reduce fat tissue and increase the amount of lean tissue. These beneficial changes are prominent among previously inactive subjects with high BMI.

Conference on "Multidisciplinary approaches to nutritional problems". Symposium on "Diabetes and health". Challenges in the study of causation of obesity

Use of the energy balance equation for understanding the causation of obesity is discussed. Its basis on the thermodynamic laws is expressed in mathematical models for body-weight changes. Only a very small net energy surplus per time unit constitutes the energy deposition during weight gain, making measurements of its components difficult. The physical laws provide exact quantitative relationships between energy intake, energy expenditure and deposition of energy, but cannot disentangle the initiating and driving forces of the energy imbalance, which may also be an active storage of fat in adipose tissue. These and various other limitations of the energy balance model warrant cautiousness in using the model in studies of obesity causation. Weight gain may be self-promoting and mathematical feedback models allowing estimation of such effects show that they are realistic. Predisposition and susceptibility should be distinguished, and susceptibility as a modifiable predisposition, the genetic and environmental contribution to predisposition and its usefulness as targets for prevention and treatment are discussed. Current progress in unravelling genetic predisposition, the complex genetically-determined mechanisms, the slower progress in unravelling the environmental influences, the different nature of genetic and environmental influences, the possible pathways of environmental influences and the environmental influences as mediators of genetic effects are addressed. The evidence behind the prevailing concept of the 'obesogenic' environment is critically analysed. Finally, particular opportunities for the identification of the causes of the obesity epidemic by detailed analysis of an observed irregular development of the epidemic over long time periods are presented, and evidence for predisposition as a result of postnatal environmental influences is inferred from these studies.

Ruminant and industrially produced trans fatty acids: health aspects

Fatty acids of trans configuration in our food come from two different sources - industrially produced partially hydrogenated fat (IP-TFA) used in frying oils, margarines, spreads, and in bakery products, and ruminant fat in dairy and meat products (RP-TFA). The first source may contain up to 60% of the fatty acids in trans form compared to the content in ruminant fat which generally does not exceed 6%. In Western Europe, including Scandinavia, the average daily intake of IP-TFA has decreased during the recent decade due to societal pressure and a legislative ban, whereas the intake of RP-TFA has remained stable.In spite of this decrease we have found that in many countries consumption >20 g of IP-TFA in a one-meal menu consisting of some popular foods is possible, even though the average intake of IP-TFA in these countries is low. Subgroups of the populations may therefore, on average, consume >5 g IP-TFA per day. This level of consumption is generally not possible for RP-TFA. A daily intake of 5 g TFA (primarily IP-TFA) is associated with a 29% increased risk of coronary heart disease. Such an association is not found for RP-TFA up to a daily intake of 4 g.The high amount of IP-TFA in popular foods, the evidence of a more harmful effect on health by IP-TFA than by RP-TFA, and the feasibility of eliminating IP-TFA from foods without side effects for the population, suggest that a selective elimination of IP-TFA from our food is a 'low hanging fruit' in the quest for a more healthy diet for subgroups of the population.

Changes in the distributions of body mass index and waist circumference in English adults, 1993/1994 to 2002/2003

BACKGROUND

Obesity rates have increased markedly in recent years. This study investigated whether increases in adiposity over the past 10 years in England reflect across-the-board gains in adiposity or differential effects in subgroups.

METHODS

The data were from the Health Surveys for England, which include home-based measurements of height, weight and waist circumference in population-representative samples. Mean-difference (m-d) curves were calculated to examine increases in BMI and central adiposity at selected percentile points across the distribution between 1993/4 and 2002/3. The sample comprised 20,246 participants in 1993/1994 and 11 708 in 2002/2003. Patterning of population adiposity was examined in relation to gender, age and socioeconomic status (SES).

RESULTS

Both BMI and central adiposity increased markedly more in the upper part of the distribution, with intermediate increases in the middle and little change at the lower end of the distribution. The patterning and magnitude of increases in adiposity were similar for men and women, and for lower and higher SES groups. Increases at the top of the distribution were greater for younger adults, with the 90th percentile of waist circumference increasing by more than 8 cm in 10 years in young women.

CONCLUSIONS

Gains in adiposity have not been equivalent across the BMI distribution. Thinner people in 2002/3 were almost as thin as they were 10 years earlier, but fatter people were considerably fatter. This could represent progressively greater responsiveness to the 'obesogenic' environment in individuals with higher complements of susceptibility genes. These population trends have important implications for future health and services to manage severe obesity.

Prevalence of obesity in Denmark

There has been a pronounced, distinctive increase of the prevalence of obesity within almost all age groups of the Danish population, during the last 25-30 years. The largest increase has been documented in studies based on objective data from total populations and the latest data show the increase will continue. The Danish studies show heterogeneity in the development of the obesity epidemic. A close association with birth cohorts indicates a need for further aetiological research, not only into behavioural factors, but also into early life factors that may explain some of this developmental pattern.

Physical fitness profiles in young Finnish men during the years 1975-2004

PURPOSE

This population-based study describes fitness profiles in aerobic capacity (N = 387088) during the years 1975-2004, muscle performance (N = 280285) from 1982 to 2003, and body anthropometry (N = 324911) from 1993 to 2004 among the Finnish conscripts at the age of 20 yr.

METHODS

Endurance performance was tested by the 12-min running test. Muscle fitness tests consisting of sit-ups, push-ups, pull-ups, a back-muscle test, and standing long jump were scored to muscle fitness index (MFI).

RESULTS

The mean body mass of the conscripts increased from 70.8 to 75.2 kg (P < 0.01) during the years 1993-2004. The mean distance of the conscripts" 12-min running test increased first by 4% from 1975 to 1979, but after it that decreased by 12% (from 2760 m to 2434 m, P < 0.001) compared with the year 2004. MFI increased during the first decade of the follow-up, but thereafter, the number of conscripts who achieved excellent and good MFI decreased from 66.8 to 41.2% (P < 0.001) during the years 1992-2004. The physical ability of the conscripts to meet military service declined during the last 15 yr.

CONCLUSION

Both the increase in body mass and the decrease in physical fitness may lead to serious health problems in the future.

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.

Rising incidence and persistently high mortality of hospitalized pneumonia: a 10-year population-based study in Denmark

BACKGROUND

Little is known about temporal trends in the incidence and mortality of pneumonia in the general population.

METHODS

We conducted a population-based cohort study in three Danish counties (population 1.4 million) to examine changes in the incidence and 30- and 90-day mortality associated with hospitalized pneumonia between 1994 and 2004. All adults hospitalized with a first-time diagnosis of pneumonia (n = 41 793) were identified in hospital discharge registries and followed for mortality through the Danish Civil Registry System. We determined age-standardized incidence rates and adjusted mortality rates associated with calendar year, gender, age and comorbidity.

RESULTS

Between 1994 and 2003, the incidence of hospitalized pneumonia amongst adults increased from 288 per 100 000 person-years to 442 per 100 000 person-years, equivalent to an age-standardized incidence rate ratio of 1.50. The cumulative mortality within 30 and 90 days of admission was 15.2% and 21.9%, respectively, ranging from a 90-day mortality of 2.5% in patients aged 15-39 years to 34.7% in those aged 80 and over. Advanced age was the most important poor prognostic factor, followed by a high comorbidity score and male gender. The adjusted mortality rate ratios amongst patients with hospitalized pneumonia in 1999-2004, when compared with 1994-1998, were 0.89 (95% CI 0.85-0.94) after 30 days and 0.91 (95% CI 0.88-0.95) after 90 days.

CONCLUSIONS

The incidence of hospitalized pneumonia in Denmark has increased considerably during the last 10 years and, combined with persistently high mortality rates, is of clinical and public health concern.

Prevalence of overweight, obesity and physical inactivity in 20- to 29-year-old, Danish men. Relation to sociodemography, physical dysfunction and low socioeconomic status: the Odense Androgen Study

OBJECTIVE

To assess the prevalence of overweight, obesity and physical inactivity in 20- to 29-year-old men and to analyze whether sociodemography, physical dysfunction and low socioeconomic status are independent correlates of obesity and physical inactivity.

DESIGN

Population-based, cross-sectional study.

SUBJECTS

Seven hundred and eighty-three Caucasian, Danish men, aged 20-29 years recruited from 2042 respondents in a questionnaire survey of 3000 men, randomly drawn from the Danish Civil Registration System.

METHODS

Questionnaire, interview and physical examination.

RESULTS

The 783 included men and the 2042 questionnaire respondents matched the background population demographically. The 783 men matched the questionnaire respondents as regards BMI, physical activity, chronic disease, medication, smoking, sociodemography and socioeconomic status. The prevalence of overweight and obesity was 31.7 and 7.9%, respectively (World Health Organization criteria). Using waist circumference (WC) cutoffs of 94 and 102 cm, the prevalence was 16.2 and 10.6%, respectively; 24.4% were physically inactive. BMI and WC increased significantly from age 20 to 29 years. Physical activity decreased significantly with age and correlated inversely with WC, but not with BMI. Occupation, geography, partner status, fatherhood and tobacco exposure were independently related with obesity and physical inactivity. Obesity was also related to musculoskeletal complaints, whereas chronic diseases and low educational level were associated with physical inactivity. Age was not independently related with either outcome.

CONCLUSION

In affluent societies, sociodemographic changes may partly explain the age-related decrease in physical activity and the parallel increase in WC and BMI.

Major increase in prevalence of overweight and obesity between 1987 and 2001 among Danish adults

OBJECTIVE

The aim of the study was to examine the secular trends in the prevalence of obesity (BMI >or= 30.0 kg/m(2)) and overweight (25.0 <or= BMI < 30.0 kg/m(2)) in Danish adults between 1987 and 2001.

RESEARCH METHODS AND PROCEDURES

The study included self-reported weight and height of 10,094 men and 9897 women 16 to 98 years old, collected in a series of seven independent cross-sectional surveys. Prevalence and changes in prevalence of obesity and overweight stratified by sex and age groups were determined.

RESULTS

The prevalence of obesity more than doubled between 1987 and 2001, in men from 5.6% to 11.8% [odds ratio (OR) = 2.3, 95% confidence interval (CI) = 1.9 to 2.8, p < 0.0001] and in women from 5.4% to 12.5% (OR = 2.6, 95% CI = 2.1 to 3.2, p < 0.0001), with the largest increase among the 16- to 29-year-old subjects (men, from 0.8% to 7.5%, OR = 10.2, 95% CI = 4.1 to 25.3, p < 0.0001; women, from 1.4% to 9.0% OR = 7.0, 95% CI = 3.5 to 14.1, p < 0.0001). Between 1987 and 2001, the prevalence of overweight increased from 34% to 40% in men and from 17% to 27% in women.

DISCUSSION

The prevalence of overweight and obesity in Denmark has increased substantially between 1987 and 2001, particularly among young adults, a development that resembles that of other countries. There is clearly a need for early preventive efforts in childhood to limit the number of obesity-related complications in young adults.

Trends in overweight among adolescents living in the poorest and richest regions of Brazil

OBJECTIVES

We assessed changes in body mass index (BMI) among Brazilian adolescents.

METHODS

In 1975, 1989, and 1997, we conducted household surveys of the weights and statures of a probabilistic sample of about 50,000 Brazilian adolescents aged 10 to 19 years. Weighted prevalences were calculated and an analysis was performed with the sample design taken into account.

RESULTS

Adolescents of rich (southeast) and poor (northeast) regions showed a substantial increase in BMI. In the southeast, the prevalence of overweight, defined by international age- and gender-specific BMI cutoffs, for both genders reached 17% in 1997, whereas in the northeast, the prevalence tripled, reaching 5% among boys and 12% among girls. Older girls living in urban areas in the southeast showed a decrease in prevalence from 16% to 13% in the latter 2 surveys. For all boys and for young girls, the BMI values for the 85th percentile in 1997 were much higher than the 95th percentile values in 1975.

CONCLUSIONS

BMI increased dramatically in Brazilian adolescents, mainly among boys; among older girls from the richest region, the prevalence of overweight is decreasing.

Large heterogeneity of the obesity epidemic in Danish adults

OBJECTIVE

To examine to what extent the obesity epidemic is a general phenomenon in adults by assessing the secular change, by birth cohort and age, in the prevalence of obesity and median body mass index (BMI) in Danish men and women measured between 1964 and 1994.

DESIGN

Multiple cross-sectional population surveys.

SETTING

The greater Copenhagen area of Denmark.

SUBJECTS

The study included 17,065 men (30 336 observations) and 13,417 women (24,065 observations), aged 20-84 years.

MAIN OUTCOME MEASURES

Trends in median BMI and prevalence of obesity estimated from measured height and weight in 10-year age groups.

RESULTS

In general the prevalence of obesity was increasing, although in an irregular way: among men in two phases, during the 1970s and 1990s and among women only during the 1990s. Great heterogeneity was observed between birth cohorts and age groups. There was only little indication of an increasing trend in obesity prevalence for women, except for the 55-64-year-olds. In men, the prevalence of obesity was increasing in all age groups except in the youngest ones, and it was statistically significant only for men aged 35-74 years. There was no significant linear change in median BMI in any group, except for an increasing trend among men aged 50 years and above.

CONCLUSION

Although the overall Danish trend for obesity prevalence, similar to trends world-wide, showed a marked increase, the trend was very heterogeneous and generally neither uniform nor significantly positive; the changes were irregular, different among men and women, and different in the different age and birth cohorts. The obesity problem in middle-aged and older men of certain birth cohorts poses a specific public health challenge. Future studies of determinants behind the heterogeneity in the development of the obesity epidemic may provide clues to its causes.

An observational study of slimming behavior in Denmark in 1992 and 1998

OBJECTIVE

To elucidate how frequent weight-loss attempts are made, the methods used to achieve weight loss, and the extent to which the outcome is positive.

RESEARCH METHODS AND PROCEDURES

Two independent interviews were conducted in 1992 and in 1998, each with 1200 randomly selected adult subjects. Each survey was designed to ensure an equal distribution of age, gender, and geographical regions in Denmark.

RESULTS

The proportion of subjects having attempted weight loss did not change from 1992 to 1998, although the prevalence of overweight and obesity increased from 1992 (overweight, 30%; obesity, 6%) to 1998 (overweight, 35%; obesity, 8%). Almost twice as many women (61%) than men (32%) had attempted weight loss (p < 0.0001). Slimming occurred more often in subjects <50 years (51%) than >50 years (39%) (p < 0.0001), although overweight and obesity were more frequent in the elderly. Over-the-counter diet pills or meal replacements were associated with a negative outcome of slimming treatment (p < 0.0001).

DISCUSSION

Approximately half of all adult Danes have attempted weight loss, particularly women and individuals <50 years. This finding is inconsistent with the fact that overweight and obesity are more prevalent in men and in individuals >50 years. Changes in habitual diet and increased physical activity are the most prevalent modes of slimming, whereas the use of over-the-counter diet pills or meal replacements has decreased from 1992 to 1998. This development may have a positive impact on future body- weight-management strategies.

Secular trends in overweight and obesity among Finnish adolescents in 1977-1999

OBJECTIVE

To study the trends in overweight and obesity among Finnish adolescents in 1977-1999.

DESIGN

Mailed surveys every other year.

SUBJECTS

Nationally representative samples of 12, 14, 16 and 18-y-olds (n = 64,147, response rate 78.9%).

METHODS

Overweight and obesity were measured by body mass index (BMI) and relative weight (RW) based on self-reported height and weight. BMI > or = the 85th percentile cut-off point for BMI in each age- and sex-specific group in the entire data set was considered as overweight, and BMI > or = 95th percentile cut-off point as obesity. RW > or = 110% and > or = 120%, calculated as the individual's weight divided by the mean weight in each age- and sex-specific height percentile group in the entire data set, were considered as overweight and obesity, respectively. The trends in overweight and obesity are described by the change in the 85th and 95th percentile cut-off points of BMI over time. The prevalence of overweight and obesity is also reported using BMI reference values recommended for international comparisons. Because of the similarity of the BMI and the RW criteria in classifying adolescents as overweight and obese, only results based on BMI are presented.

RESULTS

Overweight and obesity increased linearly in all sex and age groups from 1977 to 1999. Depending on the age group, the average increase in the 85th percentile cut-off point of the BMI per 10 y was 0.6-1.1 kg/m2 in boys and 0.3-0.7 kg/m2 in girls. The 95th percentile cut-off point of the BMI for boys and girls increased by 1.1-1.6 kg/m2 and by 0.6-1.0 kg/m2 per 10 y, respectively. In boys, the increase in overweight and obesity was largest in the two youngest age groups. In girls, the increase in overweight was largest in the oldest age group, and that of obesity both in the 14 and 18-y-olds. Overweight and obesity increased more in boys than in girls in all age groups except in the 18-y-olds among whom the increase was similar in both sexes. Examination of the entire BMI distribution showed that there was little or no change over time at the lower (5th, 15th) and middle (50th) percentiles, but increasing differences at the upper end of the distribution, the increases in the 95th percentile being even more marked than those in the 85th percentile curves. According to international reference values, the age-standardized prevalence of overweight increased in boys from 7.2 to 16.7%, and in girls from 4.0 to 9.8%, between 1977 and 1999. The prevalence of obesity in boys was 1.1% in 1977 and 2.7% in 1999, and in girls 0.4 and 1.4%, respectively.

CONCLUSION

Overweight and obesity increased remarkably among Finnish adolescents from 1977 to 1999. The changes concentrated at the upper end of the BMI distribution, suggesting that factors behind this development have influenced only a part of the adolescent population.

Obesity and body mass index in Spain: the 'single population' theory revisited

OBJECTIVE

The 'single population' theory suggests that the distribution of body mass index (BMI) moves up and down as a whole. We test directly whether this theory is valid among the adult population within one country over time, by examining the association between median BMI and the prevalence of obesity in the adult population of Spain's 17 regions between 1987 and 1993.

DESIGN AND SETTING

Ecological study using data from two national health surveys.

SUBJECTS AND INTERVENTIONS

Self-reported weight and height for persons aged 20-64 y were drawn from representative Spanish-population samples from two similar National Health Surveys carried out in 1987 (n = 20 705) and 1993 (n = 15 490).

MAIN OUTCOME MEASURES

Correlation and linear regression between the difference in median BMI and the difference in the prevalence of obesity (BMI > or = 30 kg/m(2)) between 1987 and 1993.

RESULTS

Between 1987 and 1993 the change in median BMI was in general strongly correlated with the change in the prevalence of obesity (r = 0.85; P < 0.001). The correlation is greater in women, persons over 45 y, and those with lower educational levels. Between 1987 and 1993 each unit of increase in median BMI is associated with an absolute increase of 5.1% (95% CI 3.3-6.8%) in the prevalence of obesity.

CONCLUSIONS

The single population hypothesis holds true among the adult population within a whole country over time. This could be useful for monitoring and understanding the prevalence of obesity within a population.

Ten-year trends in overweight and obesity among Danish men and women aged 30-60 years

INTRODUCTION

The prevalence of obesity is increasing worldwide. Published data of the development of obesity among adult Danes is based primarily on self-reported information of body weight and height. The objective of the study was, therefore, to describe the development over 10 y in moderate and severe overweight in Danish adults aged 30-60 y.

METHOD

1,940 men and 1,844 women, born in 1922, 1932, 1942 or 1952, participated in a first survey in 1982. A total of 808 men and 816 women, born in 1932, 1942, 1952 or 1962, were included in a second survey in 1992. The surveys originated in the Danish MONICA studies. Moderate and severe overweight were determined on the basis of body mass index (BMI).

RESULTS

The prevalence of severe overweight (BMI > or = 30 kg/m2) increased from approximately 10 to 13% in men and from 9 to 11% in women (both P=0.03), corresponding to an increase in the overweight Danish subjects of about 75,000 in this age group over the period. The increase was most pronounced in the young age groups. The proportion of severe overweight in those 30 y old increased from 3.1 to 7.8% in women (P= 0.006) and from 5.0 to 9.4% in men (P=0.045). In 1992, 8% of men with more than 12 y of schooling were severely overweight, compared to 3% 10 y earlier (P= 0.045). In women with more than 12 y of schooling there was no difference. In the group with less than 7 y schooling, the proportion of severely overweight women increased from 12.8 to 19.8% (P=0.02) and severely overweight men from 15.0 to 21.2% (P= 0.048). After adjustment for differences in age and education the proportion of severely overweight men remained greater in 1992 compared to 1982. In women the proportion of severe overweight had increased among the 30 y olds only, but not the 40-60 y olds.

DISCUSSION

The increase in obesity in the Danish population is in line with the general international increase. There is a considerable increase in the proportion of adult Danes with a BMI > or = 30 kg/m2 corresponding to an estimated extra 75,000 severely overweight 30-60 y olds in the period. The study also demonstrates that the increase in severe overweight is most pronounced among the men and the younger women.

New developments in obesity

Obesity is an important health problem. Worldwide epidemiological data show that its frequency is rising steeply, probably because of a reduction in physical activity and bad eating habits. Health risks are most prominent in the central type of obesity, due to the relatively increased lipolytic activity, which leads to a series of events. The overall results of treatment are not satisfactory. Drugs, such as orlistat, fluoxetine, and ephedrine/caffeine, may be useful. The first results with leptin treatment are encouraging, but not yet optimal. Research on various neuropeptides and beta3-agonists is promising. Prevention of obesity is extremely important but difficult.

The obesity epidemic in children and adults: current evidence and research issues

PURPOSE

The term "epidemic" of obesity implies that obesity is a characteristic of populations, not only of individuals. The purpose of this paper is to review evidence on obesity in populations and to identify future research issues.

METHODS

To examine recent increases in the population prevalence of overweight or obesity, a literature search was undertaken.

RESULTS

Trends in overweight or obesity among adults showed considerable variability internationally. Some countries, including Canada, Finland (men), New Zealand, the United Kingdom, the United States, and Western Samoa showed large increases in prevalence (>5 percentage points), whereas several other countries showed smaller or no increases. Overweight is also increasing among children and adolescents, at least in some countries. It is not clear what the expected prevalence of overweight or obesity might be in the current environment, and these findings may be most usefully viewed as shifts in the distribution of a population characteristic. The reasons for these shifts are not clear. The health implications of these shifts are also not clear, in part because trends in cardiovascular risk factors do not always parallel trends in obesity. Of the classic epidemiologic triad of host, agent, and environment, the environment has often received the least attention.

CONCLUSIONS

The economic, social, and cultural factors that influence the distribution of body mass index in a population are not well understood. Future research needs include continued monitoring of trends in obesity and in related health conditions and observational studies to examine the causes of these trends. Public health research should aim at defining realistic goals and strategies to improve health in an environment conducive to high levels of overweight and obesity.

The American paradox: the role of energy-dense fat-reduced food in the increasing prevalence of obesity

Although surveys have reported that the fat content of the diet has decreased over past decades, the prevalence of obesity has continued to rise in Europe and North America. This phenomenon, 'the American paradox', has been attributed partly to an inability of the reduction in dietary fat to reduce excess body fat, and partly to the over-consumption of low-fat products, which, despite their reduced fat content, have in some cases been accused of maintaining a high energy density due to low fibre and water contents, and a high content of refined carbohydrates. In Denmark, the prevalence of obesity has increased in a period in which national dietary surveys have reported a reduction of more than 10% in dietary fat content. Analysing the Danish situation, it seems unlikely that the occurrence of the American paradox in Denmark is caused by the increased consumption of energy-dense, low-fat foods. Other explanations, e.g. the under-reporting of dietary fat in surveys and the clustering of obesity-promoting lifestyles in subgroups of the population, should be sought.