Lifestyleobesity Women Men

download Lifestyleobesity Women Men

of 8

Transcript of Lifestyleobesity Women Men

  • 8/11/2019 Lifestyleobesity Women Men

    1/8

    RISK FACTORS

    The contribution of lifestyle factors to socioeconomic differences in obesity

    in men and women a population-based study in Sweden

    Anu MolariusCentre for Public Health Research, Karlstad University, Karlstad, Sweden

    Accepted in revised form 4 October 2002

    Abstract. Background: The objective was to investi-

    gate whether and to what extent the association be-

    tween socioeconomic status and obesity can be

    explained by lifestyle factors. Methods: The rela-

    tionship between socioeconomic status (SES) and

    obesity, and the role of lifestyle factors such assmoking, physical activity, heavy alcohol use, avoi-

    dance of dietary fat and propensity to eat fiber-rich

    food, was studied in a cross-sectional population-

    based study consisting of 6394 men and women aged

    2574 years in Va rmland County in Sweden. Edu-

    cational level was used for measuring SES. The

    contribution of the measured lifestyle factors was

    assessed using logistic regression models. Results:

    12% of men and 14% of women were obese. Subjects

    with high education were leaner than subjects with

    low education, except among elderly women (65

    74 years). Although many lifestyle factors were re-

    lated to obesity and SES in this study, only a part

    (1829%) of the association between educational

    level and obesity could be explained by the measured

    lifestyle factors. Physical inactivity and heavy alcohol

    use were the main factors contributing to this asso-ciation, whereas smoking and the measured dietary

    attitudes towards fat and fiber had little additional

    effect. Conclusions: The findings of this study are

    consistent with the view that socioeconomic differ-

    ences in obesity and its consequences can only partly

    be reduced by changes in lifestyle. Longitudinal

    studies, a more detailed investigation of the role of

    dietary factors and more studies including elderly

    subjects are, however, recommended to further elu-

    cidate the association between SES and obesity.

    Key words: Lifestyle, Obesity, Population studies, Socioeconomic status

    Background

    An inverse association between socioeconomic status

    (SES) and relative body weight has been observed

    among women in affluent societies [1, 2]. The asso-

    ciation is less consistent among men, although in

    most western countries an inverse association has

    also been found in men. Likewise, in Sweden persons

    with high SES are leaner than persons with low SES

    [35] and this association has been rather stable

    during the last decade [5].

    Socioeconomic inequalities in self-perceived health,

    morbidity and mortality exist in many countries [6].

    Because obesity is related to the incidence of several

    chronic diseases and mortality [710], socioeconomic

    differences in the prevalence of obesity may act as one

    factor through which these inequalities emerge [11].

    Therefore it is important to investigate possible ex-

    planations for socioeconomic differences in obesity.

    Lifestyle factors, such as physical activity, dietary

    habits, smoking and alcohol intake are related to

    relative weight [1215] and also differ between so-cioeconomic groups in such a way that the most

    privileged often have healthier lifestyle [6, 1618].

    Because these behavioural factors are potentially

    modifiable, it is of interest to know whether and to

    what extent the association between SES and obesity

    can be explained by these factors. Some studies have

    suggested that differences in health behaviour only

    partly explain the association between SES and rel-

    ative weight [11, 1921]. These studies have, however,

    not been population-based and they have studied

    subjects only within a limited age range e.g. they have

    not included elderly subjects. There are also meth-

    odological shortcomings in measuring lifestyle factors

    in these studies. Therefore the evidence remains in-

    conclusive.

    In the present study the relationship between SES

    and obesity, and the role of lifestyle factors in this

    relationship, was investigated in a cross-sectional

    population-based study consisting of 6394 men and

    women aged 2574 years in the Va rmland County in

    Sweden. Educational level was used for measuring

    SES.

    Methods

    The data were derived from a random sample of the

    adult population aged 1879 years in Va rmland

    European Journal of Epidemiology18: 227234, 2003. 2003Kluwer Academic Publishers. Printed in the Netherlands.

  • 8/11/2019 Lifestyleobesity Women Men

    2/8

    County in western Sweden. The data were gathered

    between 21 March and 19 May 2000 using a postal

    survey questionnaire. The overall response rate was

    70%. A total of 8288 subjects answered the ques-

    tionnaire. Because most of those aged 1824 years

    had not completed their education and the informa-tion on education was missing for most of those aged

    75 years or over, these age groups were excluded

    from the study. 6394 men and women aged 25

    74 years with data on body mass index (BMI) and

    educational level were included in the study.

    Relative weight was measured using BMI. BMI

    was calculated from self-reported weight and height

    as weight divided with height squared (kg/m2). The

    participants were categorised in concordance with the

    WHO guidelines [22] as obese when BMI was equal

    to or over 30 kg/m2.

    Educational level was obtained through recordlinkage from a national education register. The re-

    cord linkage was carried out by means of personal

    identification codes. Educational level refers to the

    end of year 1999 and it was categorised into three

    classes: low (elementary school), medium (upper

    secondary school), and high (at least 3 years of uni-

    versity or corresponding education).

    Data on lifestyle factors were obtained using the

    questionnaire. Physical activity was measured with a

    question: How much do you exercise physically in

    your leisure time? with the options little exercise

    (walking, bicycling or other light exercise less than

    2 hours a week), moderate exercise (walking, bicy-cling or other light exercise more than 2 hours a

    week), moderate regular exercise (exercising 12

    times a week at least for half an hour at a time in

    jogging, playing tennis, bicycling, exercising at a gym

    or other moderate exercise that makes one to sweat)

    and vigorous exercise and training (exercising or

    competing at least three times a week at least for half

    an hour at a time in team sports, jogging, playing

    tennis, swimming or other vigorous exercise). Because

    the survey was carried out between late March and

    May, the possibilities for example for walking are not

    affected by winter circumstances in this area ofSweden.

    Smoking was asked with a question: Do you

    smoke? with the answer options No, I have never

    smoked regularly, No, I have stopped smoking,

    Yes, occasionally, and Yes, daily. Alcohol use was

    obtained with a question asking how often it hap-

    pened that the subject drank at the same occasion

    alcohol corresponding to at least half a bottle of

    strong liquor (with giving the corresponding amount

    in wine and beer). The options ranged from At least

    five times a week to Never, and were for the anal-

    ysis grouped into three categories Once a month or

    more often, More seldom and Never.

    There was no information about actual intake of

    fat and fiber, but dietary attitudes towards fat and

    fiber were asked with a question: Do you try to avoid

    fat food? and Do you try to eat fiber-rich food (such

    as wholemeal bread, mu sli or root vegetables)?. The

    answer options were Not at all, Yes, to some ex-

    tent, and Yes, I am very particular about it.

    Statistical methods

    As background information the prevalence of obesi-

    ty, low education and the measured unhealthy life-

    style factors are reported by three age categories

    (2544, 4564, and 6574 years), and the prevalence

    of obesity and unhealthy lifestyle factors by educa-

    tional level. The association between educational

    level and relative weight was assessed by calculating

    the difference in mean BMI between the educational

    levels in the three age categories (with further ad-

    justment for age) in a general linear model.

    The contribution of lifestyle factors to the associ-

    ation between educational level and obesity was

    studied using logistic regression models where obesity

    was the dependent variable. The contribution of each

    lifestyle factor was assessed by adding these factors

    one by one into the model containing obesity and

    educational level. Smoking was added first, then

    physical activity and heavy alcohol use, and finally

    dietary attitudes. Smoking was added first, because

    an inverse association was assumed [14] and dietary

    attitudes last, because only an indirect association

    was assumed. Only those factors that were associated

    with obesity were included in the final model. Because

    age was strongly related to both obesity and educa-tional level, all models were adjusted for age. Since

    the association between age and obesity was non-

    linear, age was used as a categorical variable (5-year

    age classes). Because there was no association be-

    tween educational level and relative weight among

    women aged 6574 years, these were excluded from

    further analysis. All analyses were performed sepa-

    rately for men and women.

    To confirm the results between obesity, SES and

    lifestyle factors obtained in the logistic regression

    analysis, the same analyses were repeated using gen-

    eral linear models where BMI was the continuousdependent variable.

    The contribution of lifestyle factors to the associ-

    ation between SES and obesity was calculated as the

    proportion (percentage) of the difference in the odds

    ratios between the crude model (C) and the model

    including the lifestyle factors (final model, F) in re-

    lation to the increased risk in the crude model:

    100 ORC ORF

    ORC 1 %

    In the corresponding general linear model the con-

    tribution of lifestyle factors to the association be-

    tween SES and BMI was calculated as the

    proportional change in the difference in mean BMI

    between the educational categories before and after

    adjustment for the measured lifestyle factors.

    228

  • 8/11/2019 Lifestyleobesity Women Men

    3/8

    Results

    Table 1 shows the number of participants and the

    prevalences of obesity and low education by gender

    and age group. Obesity was relatively common in the

    study population, 12% of men and 14% of womenwere obese. Obesity increased with age, except among

    men in the oldest age group. The proportion of

    subjects with low education increased strongly with

    age. The table also shows the proportion of physi-

    cally inactive, daily smokers, heavy alcohol users and

    subjects with unhealthy dietary attitudes. About one-

    fifth of the population was physically inactive and

    physical inactivity was most common among young

    (2544 years) men. It was the moderate exercise

    which increased with age in men, whereas vigorous

    exercise decreased with age. Women were more often

    smokers than men, except among the elderly (6574 years). Heavy use of alcohol was very common

    among men, especially among young men, almost

    half of them consumed alcohol corresponding to half

    a bottle strong liquor at least once a month. Dietary

    attitudes showed a similar pattern as heavy alcohol

    use. Women were more often than men trying to

    avoid fat food and to eat fiber-rich food. Older sub-

    jects had healthier dietary attitudes than younger

    subjects.

    Obesity was more common among subjects with

    low education than among subjects with high edu-

    cation (Table 2). Also lifestyle habits differed con-

    siderably between the educational levels. Those with

    low education were more often physically inactive,

    smokers, used more often alcohol and had un-healthier dietary attitudes than those with high edu-

    cation. Those with middle level education were,

    however, even more often heavy alcohol users and

    had unhealthier dietary attitudes (among men) than

    those with low education. Because also age differed

    between the educational levels (Table 2) and it was

    related to lifestyle factors (Table 1) the subsequent

    analyses were adjusted for age.

    Figure 1 shows the differences in mean BMI be-

    tween the high and low educational levels in men and

    women in the three age categories. Subjects with high

    education were leaner than subjects with low educa-tion in all age groups among men. A similar inverse

    association was observed among women aged 25

    64 years, this association was particularly strong

    among women aged 4564 years. There was, how-

    ever, no association between educational level and

    relative weight among elderly (6574 years) women.

    Subjects with high educational level were also leaner

    than subjects with middle level education in all age

    groups except in elderly women (now shown).

    Table 1. Number of subjects, prevalence of obesity, low education, physical inactivity, daily smoking, heavy alcohol use,

    and unhealthy dietary attitudes by age group in men and women (crude percentages)

    Men Women

    Age group 2544 4564 6574 2544 4564 6574

    n 1033 1124 872 1233 1285 847

    Obese (%) 10.9 13.2 12.7 10.6 14.2 17.5

    Low education (%) 14.8 38.4 59.6 12.7 27.7 57.4

    Physically inactive (%) 27.1 22.7 17.3 19.0 21.2 18.3

    Daily smokers (%) 13.2 17.2 13.3 21.0 22.0 10.7

    Heavy alcohol use at least once a month (%) 43.9 28.3 19.5 13.0 9.0 3.2

    Does not try to avoid fat food (%) 54.1 37.8 32.0 27.3 12.9 13.2

    Does not try to eat fiber-rich food (%) 47.2 28.6 17.7 22.7 11.6 8.9

    Table 2. Number of subjects, mean age, prevalence of obesity, physical inactivity, daily smoking, heavy alcohol use, and

    unhealthy dietary attitudes by educational level in men and women (crude percentages)

    Men Women

    Educational level Low Medium High Low Medium High

    n 1155 1716 208 991 2061 313

    Mean age (SD) 59.5 (12.4) 47.1 (14.3) 52.7 (13.7) 59.4 (13.2) 47.0 (13.9) 48.8 (13.3)

    Obese (%) 14.8 11.5 5.3 17.2 13.0 7.7

    Physically inactive (%) 21.5 24.8 12.7 23.9 18.2 16.6

    Daily smokers (%) 17.6 13.6 8.7 20.3 19.8 7.7Heavy alcohol use at least once a month (%) 28.1 35.0 15.5 7.7 10.4 3.9

    Does not try to avoid fat food (%) 38.2 44.9 33.8 18.5 18.8 14.3

    Does not try to eat fiber-rich food (%) 28.8 35.4 18.3 16.1 15.3 9.7

    229

  • 8/11/2019 Lifestyleobesity Women Men

    4/8

    Table 3 shows the results from the logistic regres-

    sion analysis among men aged 2574 years. Physical

    inactivity and alcohol use were positively associated

    with obesity. The association between obesity and

    smoking was not statistically significant in men

    (p 0:41). Dietary attitudes were not associated withobesity in men when adjusted for the other lifestyle

    factors (p 0:28 for avoidance of dietary fat andp 0:48 for propensity to eat fiber-rich food). Phys-ical inactivity had the strongest association with

    obesity. Adjustment for physical exercise and heavyalcohol use attenuated the risk of obesity between

    high and low educational levels by 25% and between

    high and medium educational levels by 29%.

    Results for women aged 2564 years were to some

    extent similar to those for men (Table 4). Adjustment

    for lifestyle factors attenuated the risk of obesity

    between high and low educational levels by 18%, and

    by 21% between high and medium educational levels

    in women. Physical inactivity was even more strongly

    associated with obesity in women than in men.

    Smoking was not related to obesity in women

    (p 0:19). Avoidance of dietary fat was related toobesity in women but in an unexpected way. Those

    who did not try to avoid fat food were less often

    obese than those who tried to avoid fat food. This

    suggests that avoidance of fat food can be interpreted

    as a consequence of rather than a risk factor for

    obesity in women, i.e. that obese women try to avoid

    fat food more often than normal weight women.

    Propensity to eat fiber-rich food was not associatedwith obesity in women (p 0:55).

    The results using BMI as a continous dependent

    variable (general linear model, not shown) were in

    concordance with the results obtained from the lo-

    gistic regression analysis. The proportions explained

    by the measured lifestyle factors were slightly lower

    than for obesity. Twenty-two percent of the difference

    in mean BMI between high and low educational

    levels and 24% between high and medium educa-

    Figure 1. Difference in mean BMI (kg/m2) in subjects with low educational level compared with subjects with high edu-

    cational level in three age categories in men and women (adjusted for age).

    Table 3. Odds ratios (95% confidence interval in parenthesis) for risk of obesity by educational level adjusted for lifestylefactors associated with obesity (all models adjusted for age) among men aged 2574 years (n = 2814)

    Crude Adj. for physical activity

    Adj. for physical activity

    and alcohol use

    Education, high 1 (ref.) 1 (ref.) 1 (ref.)

    Medium 2.4 (1.3, 4.5) 2.2 (1.1, 4.1) 2.0 (1.1, 3.8)

    Low 3.0 (1.6, 5.7) 2.7 (1.4, 5.1) 2.5 (1.3, 4.8)

    Physical activity, vigorous exercise 1 (ref.)

    Moderate regular 1.0 (0.6, 1.7)

    Moderate 1.3 (0.8, 1.9)

    Inactive 2.4 (1.6, 3.8)

    Heavy alcohol use, never 1 (ref.)

    More seldom than monthly 1.2 (0.9, 1.6)

    Monthly 1.5 (1.1, 2.1)

    230

  • 8/11/2019 Lifestyleobesity Women Men

    5/8

    tional levels was explained by the measured lifestyle

    factors in men. In women the corresponding pro-

    portions were 12 and 20%.

    Discussion

    As in most other western populations, subjects withhigh educational level were leaner than subjects with

    low educational level in the present study population

    of men and women aged 2564 years. Among the

    elderly aged 6574 years, however, there was an in-

    verse association between educational level and rel-

    ative weight among men only. Although many

    lifestyle factors were related to obesity and SES in

    this study, only a part (1829%) of the association

    between educational level and obesity could be ex-

    plained by the measured lifestyle factors. The con-

    tribution of the measured lifestyle factors was

    somewhat bigger in men than in women. Physicalinactivity and heavy alcohol use were the main fac-

    tors contributing to the association between educa-

    tional level and obesity, whereas smoking and dietary

    attitudes towards fat and fiber had little additional

    effect on this association.

    The total caloric intake, the actual intake of fat and

    other dietary components were not measured in the

    present study. There were only two questions about

    diet and these are not sufficient to measure unhealthy

    dietary habits. Measuring dietary intake has been

    found to be difficult since there is a considerable

    underreporting of caloric intake among the obese

    subjects and the underreporting seems to be food-

    specific [23, 24]. This might also be the reason why

    evidence on the association between dietary habits

    and SES is mixed [2527]. In addition, dietary fiber,

    but not fat, has been found to some extent explain

    differences in prevalences of obesity between popu-

    lations [28]. In the present study, there were socio-

    economic differences in avoiding fat food and trying

    to eat fiber-rich food. These factors were however not

    related to obesity when adjusted for the other mea-

    sured lifestyle factors, except trying to avoid fat food

    which was inversely related to obesity in women. Thelatter implies that obese women are more often trying

    to avoid fat food than non-obese women. Whether

    their actual fat intake is lower that of non-obese

    women cannot be assessed from the present data.

    Wamala et al. [21] found that unhealthy dietary

    habits were the second strongest factor after repro-

    ductive history accounting for socioeconomic differ-

    ences in obesity among middle-aged women. A more

    careful study about the role of the dietary habits in

    the general population is therefore warranted, espe-

    cially an investigation how dietary habits contribute

    to deliberate weight control.Because alcohol has high caloric density, alcohol

    intake is usually associated with obesity. In some

    studies alcohol intake has not been associated with

    relative weight which might be due to difficulties in

    measuring alcohol intake accurately [2931]. In ad-

    dition, the association has been found to differ be-

    tween men and women, with a positive association

    often found in men but a negative association in

    women [30]. This may be due to the fact that the same

    cut-off points for alcohol intake have usually been

    used both for men and women whereas the actual

    intake is much lower in women than in men. In this

    study the actual alcohol intake was not measured but

    the subjects were instead asked about the frequency

    of heavy alcohol use. Heavy alcohol use was related

    to both obesity and low SES and explained part of

    Table 4. Odds ratios (95% confidence interval in parenthesis) for risk of obesity by educational level adjusted for lifestyle

    factors associated with obesity (all models adjusted for age) among women aged 2564 years (n = 2406)

    Crude

    Adj. for physical

    activity

    Adj. for physical

    activity and

    alcohol use

    Adj. for physical activ-

    ity, alcohol use and

    avoidance of dietary fat

    Education, high 1 (ref.) 1 (ref.) 1 (ref.) 1 (ref.)

    Medium 2.4 (1.4, 4.1) 2.2 (1.3, 4.0) 2.2 (1.3, 3.8) 2.1 (1.2, 3.7)

    Low 2.7 (1.5. 4.8) 2.4 (1.3, 4.4) 2.3 (1.3, 4.2) 2.4 (1.3, 4.2)

    Physical activity, vigorous

    exercise

    1 (ref.)

    Moderate regular 2.8 (1.3, 6.1)

    Moderate 4.8 (2.3, 9.9)

    Inactive 9.6 (4.6, 20.3)

    Heavy alcohol use, never 1 (ref.)

    More seldom than monthly 1.2 (0.9, 1.6)

    Monthly 2.0 (1.1, 2.3)

    Tries to avoid fat food, veryeagerly

    1 (ref.)

    To some degree 0.6 (0.5, 0.9)

    Not at all 0.4 (0.2, 0.6)

    231

  • 8/11/2019 Lifestyleobesity Women Men

    6/8

    the differences in obesity by SES. This effect was

    more marked in men than in women.

    Smoking was not associated with obesity in the

    present study. Even though an inverse association

    between smoking and obesity has been reported for

    most countries, there are studies that have shown alack of association between smoking and obesity in

    other populations with low prevalences of smoking

    [14]. This might be due to that in countries with very

    low smoking prevalence smokers are a selected group

    of people with also other unhealthy lifestyle habits.

    The finding that there was an inverse association

    between SES and obesity among elderly men but not

    among elderly women has no immediate explanation.

    Most studies on socioeconomic differences in obesity

    have investigated middle-aged or working-age popu-

    lations [2, 5, 11, 1921, 32] and those which have

    included elderly have not studied them separately [3,4, 33]. The increase in obesity after the age of 65 years

    in women (but not in men), changes in the educa-

    tional system over the past decades, the small number

    of elderly women with high educational level, and

    possible overrepresentation of diseases which lead to

    weigth reduction among low educated subjects are

    factors that may have contributed to the lack of as-

    sociation between SES and obesity in elderly women.

    The association between SES and obesity among el-

    derly requires further research.

    In the present study data on weight and height

    were self-reported. Self-reported data have been

    found to underestimate the actual prevalence ofoverweight and obesity [34, 35]. This would, however,

    more likely lead to an underestimation of the

    relationship between SES and obesity than to over-

    estimate it, since the distribution of BMI using self-

    reported data becomes more limited. Socioeconomic

    differences in self-report bias cannot, however, be

    excluded. For example, high SES subjects (who are

    more health conscious) may underestimate their

    weight and overestimate their physical activity more

    often than low SES subjects. In that case there would

    be an overestimation of the association between SES

    and obesity and the contribution of physical activityto this association. Similarly, there is a possiblity of

    underreporting of heavy alcohol use in the high SES

    subjects. This would overestimate the contribution of

    alcohol intake on the relationship between SES and

    obesity. The data on educational level were obtained

    from a national register and the quality of these data

    is considered to be good.

    The present study was cross-sectional in design and

    cannot therefore be used for drawing causal infer-

    ences about the association between SES and obesity,

    and the role of lifestyle factors in this association.

    Even though many lifestyle factors are known to be

    determinants of obesity, sometimes the reverse may

    also be true. For example, even if physical activity is

    known to be a strong determinant of obesity, obese

    subjects may find it difficult to carry out physical

    exercise, especially strenuous physical activity [36].

    The same applies to the findings concerning dietary

    attitudes in the present study: it is likely that it is the

    obese women who are most often trying to avoid fat

    food and not those trying to avoid fat food who are

    most often obese.The response rate in our study was relatively high

    (70%) for a postal questionnaire. When the respon-

    dents were compared with non-respondents, it was

    found that the respondents had slightly higher edu-

    cational level. Response rate among subjects with

    high educational level was 78% and among subjects

    with low educational level 65%. The response rate

    was also higher among older (77% in age group 65

    79 years) than younger subjects (62% in age group

    1834 years), and higher among women (75%) than

    men (66%). It is, however, unlikely that the associa-

    tions between SES, obesity and lifestyle factors ob-served among the respondents would differ to such an

    extent among the non-respondents that this would

    considerably affect the results.

    The results of this study are in concordance with

    results from other studies where lifestyle factors have

    been found to only partly explain the socioeconomic

    differences in obesity [19, 20]. It also suggests that the

    finding holds in population-based studies and among

    elderly men. Similar findings have been observed for

    weight gain. For example, Martikainen and Marmot

    [11] found that adjustment for behavioural factors

    attenuated the association between SES and weight

    gain by about 20%. This is quite near our estimatedeffect of the role of the measured lifestyle factors in

    socioeconomic differences in obesity. It cannot,

    however, be excluded that inaccuracies in the mea-

    surement of lifestyle factors in this and the other

    studies may have contributed to the low contribution

    of lifestyle factors in explaining socioeconomic dif-

    ferences in obesity.

    One possible explanation for the fact that lifestyle

    factors only partly explain the socioeconomic differ-

    ences in obesity prevalence is that higher SES subjects

    may to a greater extent deliberately control their

    weight. A recent study among British adults [33]found that especially high SES women had lower

    levels of perceived overweight, monitored their

    weight more closely and were more likely to be trying

    to loose weight than did low SES women. Another

    factor that has been found to explain the excess

    overweight among low SES women is reproductive

    history (higher parity and earlier age at menarche) [4,

    21]. These factors were, however, not measured in the

    present study. Also unfavourable psychosocial fac-

    tors have been found to be associated with obesity

    [32] and factors such as poor quality of life, low self-

    esteem and job strain have been mentioned as factors

    partly explaining the low SESobesity relationship

    [21]. However, although these factors are related to

    SES, they can also be interpreted as consequences of

    rather than risk factors for obesity and therefore their

    232

  • 8/11/2019 Lifestyleobesity Women Men

    7/8

    association with obesity should be investigated in

    longitudinal studies.

    The contribution of lifestyle factors to the socio-

    economic differences in obesity is important from a

    public health point of view. If lifestyle factors would

    explain a large part of the association between SESand obesity, changes in lifestyle would be important

    for reducing socioeconomic differences in obesity.

    Furthermore, changes in lifestyle factors would even

    be important for reducing the socioeconomic differ-

    ences in the consequences of obesity. Since the con-

    tribution of lifestyle factors such as physical inactivity

    and heavy alcohol use on the basis of this and other

    studies seems to be limited, other factors should be at

    least as important as lifestyle factors when trying to

    reduce the socioeconomic differences in obesity. Ex-

    amples of such possible other factors are reproductive

    history in women, deliberate weight control practisesand cultural factors such as what is considered as

    desirable weight.

    In conclusion, although many lifestyle factors were

    related to obesity and SES in men and women, only a

    part of the association between educational level and

    obesity could be explained by the measured lifestyle

    factors. Longitudinal studies, a more detailed inves-

    tigation of the role of dietary factors and more

    studies including elderly subjects are recommended to

    further elucidate the association between SES and

    obesity and the contribution of lifestyle factors.

    Acknowledgement

    The population survey in Va rmland was financed by

    the Va rmland County Council.

    References

    1. Sobal J, Stunkard J. Socio-economic status and obesi-

    ty: A review of the literature. Psychol Bull 1989; 105:

    260275.

    2. Molarius A, Seidell JC, Sans S, Tuomilehto J, Kuul-

    asmaa K for the WHO MONICA Project. Educationallevel, relative body weight, and changes in their relation

    over 10 years: an international perspective from the

    WHO MONICA Project. Am J Public Health 2000; 90:

    12601268.

    3. Sundquist J, Johansson SE. The influence of socio-

    economic status, ethnicity and lifestyle on body mass

    index in a longitudinal study. Int J Epidemiol 1998; 27:

    5763.

    4. Lahmann PH, Lissner L, Gullberg B, Berglund G.

    Sociodemographic factors associated with long-term

    weight gain, current body fatness and central adiposity

    in Swedish women. Int J Obes 2000; 24: 685694.

    5. Lissner L, Johansson SE, Qvist J, Rossner S, Wolk A.Social mapping of the obesity epidemic in Sweden. Int J

    Obes 2000; 24: 801805.

    6. Mackenbach JP, Kunst AE, Cavelaars AE, Groenhof

    F, Geurts JJM and the EU Working Group on So-

    cioeconomic Inequalities in Health. Socioeconomic

    inequalities in morbidity and mortality in western Eu-

    rope. Lancet 1997; 349: 16551659.

    7. Manson JE, Colditz GA, Stampfer MJ, et al. A pro-

    spective study of obesity and risk of coronary heart

    disease in women. N Engl J Med 1990; 322: 882889.8. Pi-Sunyer FX. Medical hazards of obesity. Ann Intern

    Med 1993; 119: 655660.

    9. Jousilahti P, Tuomilehto J, Vartiainen E, Pekkanen J,

    Puska P. Body weight, cardiovascular risk factors, and

    coronary mortality: 15 year follow-up of middle-aged

    men and women in eastern Finland. Circulation 1996;

    93: 13721379.

    10. Bjo rntorp P. Obesity. Lancet 1997; 350: 423426.

    11. Martikainen PT, Marmot MG. Socioeconomic differ-

    ences in weight gain and determinants and conse-

    quences of coronary risk factors. Am J Clin Nutr 1999;

    69: 719726.

    12. Seidell JC, Flegal KM. Asessing obesity: Classification

    and epidemiology. Br Med Bull 1997; 53: 238252.13. Lissner L, Heitman BL. Dietary fat and obesity: Evi-

    dence from epidemiology. Eur J Clin Nutr 1995; 49:

    7990.

    14. Molarius A, Seidell JC, Kuulasmaa K, Dobson AJ,

    Sans S for the WHO MONICA Project. Smoking and

    relative body weight: An international perspective from

    the WHO MONICA Project. J Epidemiol Commun

    Health 1997; 51: 252260.

    15. Tremblay A. Physical activity and obesity. Baillieres

    Best Pract Res Clin Endocrinol Metab 1999; 13: 121

    129.

    16. Wagenknecht LE, Perkins LL, Cutter GR, et al. Cig-

    arette smoking behavior is strongly related to educa-tional status: The Cardia Study. Prev Med 1990; 19:

    158169.

    17. Pekkanen J, Tuomilehto J, Uutela A, Vartiainen E,

    Nissinen A. Social class, health behaviour, and mor-

    tality among men and women in eastern Finland. Br

    Med J 1995; 311: 589593.

    18. Manhem K, Dotevall A, Wilhelmsen L, Rosengren A.

    Social gradients in cardiovascular risk factors and

    symptoms of Swedish men and women: The Goteborg

    MONICA study 1995. J Cardiovasc Risk 2000; 7: 359

    368.

    19. Jeffery RW, French SA, Forster JL, Spry VM. Socio-

    economic status differences in health behaviours related

    to obesity: The Healthy Worker Project. Int J Obes1991; 15: 689696.

    20. Jeffery RW, French SA. Socioeconomic status and

    weight control practises among 20- to 45-year-old

    women. Am J Public Health 1996; 86: 10051010.

    21. Wamala SP, Wolk A, Orth-Gomer K. Determinants

    of obesity in relation to socioeconomic status among

    middle-aged Swedish women. Prev Med 1997; 26: 734

    744.

    22. Obesity Preventing and Managing the Global Epi-

    demic. Report of a WHO Consultation on Obesity.

    Geneva 35 June 1997. WHO/NUT/NCD/98.1.

    23. Heitman BL, Lissner L. Dietary underreporting by

    obese individuals is it specific or non-specific? Br MedJ 1995; 311: 986989.

    24. Braam LA, Ocke MC, Bueno de Mesquita HB, Seidell

    JC. Determinants of obesity-related underreporting of

    energy intake. Am J Epidemiol 1998; 147: 10811086.

    233

  • 8/11/2019 Lifestyleobesity Women Men

    8/8

    25. Shimakawa T, Sorlie P, Carpenter MA, et al. Dietary

    intake pattern and sociodemographic factors in the

    atherosclerosis risk in communities study. ARIC Study

    Investigators. Prev Med 1994; 23: 769780.

    26. Irala-Estevez JD, Groth M, Johansson L, Oltersdorf U,

    Prattala R, Martinez-Gonzalez MA. A systematic re-view of socio-economic differences in food habits in

    Europe: Consumption of fruit and vegetables. Eur J

    Clin Nutr 2000; 54: 706714.

    27. Lindstro m M, Hanson BS, Brunner E, et al. Socio-

    economic differences in fat intake in a middle-aged

    population: Report from the Malmo Diet and Cancer

    Study. Int J Epidemiol 2000; 29: 438448.

    28. Kromhout D, Bloemberg B, Seidell JC, Nissinen A,

    Menotti A. Physical activity and dietary fiber determine

    population body fat levels: The Seven Countries Study.

    Int J Obes 2001; 25: 301306.

    29. Eisen SA, Lyons MJ, Goldberg J, True WR. The impact

    of cigarette smoking and alcohol consumption on

    weight and obesity. An analysis of 1911 monozygoticmale twin pairs. Arch Intern Med 1993; 153: 24572463.

    30. Hellerstedt WI, Jeffery RW, Murray DM. The associ-

    ation between alcohol intake and adiposity in the gen-

    eral population. Am J Epidemiol 1990; 132: 594611.

    31. Suter PM, Hasler E, Vetter W. Effects of alcohol

    on energy metabolism and body weight regulation: Is

    alcohol a risk factor for obesity. Nutr Rev 1997; 55:

    157171.

    32. Rosmond R, Lapidus L, Bjo rntorp P. The influence of

    occupational and social factors on obesity and body fat

    distribution in middle-aged men. Int J Obes 1996; 20:

    599607.33. Wardle J, Griffith J. Socio-economic status and weight

    control practices in British adults. J Epidemiol Com-

    mun Health 2001; 55: 185190.

    34. Kuskowska-Wolk A, Ro ssner S. The true prevalence

    of obesity. Scand J Prim Health Care 1989; 7: 7982.

    35. Plankey MW, Stevens J, Flegal KM, Rust PF. Pre-

    diction equations do not eliminate systematic error in

    self-reported body mass index. Obes Res 1997; 5: 308

    314.

    36. Ball K, Crawford D, Owen N. Too fat to exercise?

    Obesity as a barrier to physical activity. Aust N Z J

    Public Health 2000; 24: 331333.

    Address for correspondence: A. Molarius, Va stmanland

    County Council, Department of Community Medicine, 721

    51 Va stera s, Sweden

    Phone:46-21-174583; Fax: 46-21-174515E-mails: [email protected], anu.molarius@

    kau.se

    234