Desire for the body normal: body image and discrepancies between self reported and measured height and weight in a British population

Gender differences in factors associated with body weight misperception

OBJECTIVE

Gender analysis in health research is important to strengthen our health system. The current study aimed to explore factors related to body weight misperception in a national sample of the general Korean population.

DESIGN

Cross-sectional study.

SETTING

South Korea, general population.

PARTICIPANTS

12,900 adults enrolled from the Seventh Korea National Health and Nutrition Examination Survey (2016-2018).

RESULTS

Disadvantageous socio-economic status was considered a predictor of participants' misperceptions of themselves as being of a healthy weight despite being overweight and as underweight despite being of a healthy weight, mainly in men. Favourable socio-economic status was considered a predictor of participants' misperceptions of themselves as being of a healthy weight despite being underweight and as overweight despite being of a healthy weight, mainly in women. Living in an urban area was an independent predictor of men's misperception of themselves as being of a healthy weight despite being overweight and women's misperception of themselves as being underweight despite being of a healthy weight. Physical inactivity was a predictor of most misperceptions in women. Psychological variables, such as stress and depression, were not significant predictors of misperception.

CONCLUSIONS

The current study highlighted the gender differences in factors related to body weight misperception. These differences suggested that more sophisticated policies should be formulated to identify solutions to health problems related to body weight.

Rounding as an indicator of bias in reported body weight in health surveys

Due to the higher costs and selection bias of directly measuring weight, the majority of body weight data are based on survey responses. However, these statements are subject to systematic biases of social desirability; therefore, it is important to evaluate the magnitude of bias through indirect indicators such as rounding of weights. Data from seven rounds of the Spanish National Health Survey from 1995 to 2017 were included in the study, with 113,284 subjects. A general rounding index of weights terminating in 0 and 5, and a partial rounding index that estimated the bias direction, were used to estimate the bias distribution in the self-reporting of body weight. All body weights were systematically rounded, although more strongly in the lower weights and even more so in the higher weights. Lower weights were rounded up, and the higher weights rounded down. Regarding gender, men had higher rounding indices than women. The subjects generally reported a weight closer to the socially desirable weight. Rounding allows estimating the historical evolution of this bias in health and nutrition surveys, having more accurate information by population segments and designing public policies against obesity aimed at the more affected social segments.

Trends in educational inequalities in obesity in 15 European countries between 1990 and 2010

BACKGROUND

The prevalence of obesity increased dramatically in many European countries in the past decades. Whether the increase occurred to the same extent in all socioeconomic groups is less known. We systematically assessed and compared the trends in educational inequalities in obesity in 15 different European countries between 1990 and 2010.

METHODS

Nationally representative survey data from 15 European countries were harmonized and used in a meta-regression of trends in prevalence and educational inequalities in obesity between 1990 and 2010. Educational inequalities were estimated by means of absolute rate differences and relative rate ratios in men and women aged 30-64 years.

RESULTS

A statistically significant increase in the prevalence of obesity was found for all countries, except for Ireland (among men) and for France, Hungary, Italy and Poland (among women). Meta-regressions showed a statistically significant overall increase in absolute inequalities of 0.11% points [95% CI 0.03, 0.20] per year among men and 0.12% points [95% CI 0.04, 0.20] per year among women. Relative inequalities did not significantly change over time in most countries. A significant reduction of relative inequalities was found among Austrian and Italian women.

CONCLUSION

The increase in the overall prevalence aligned with a widening of absolute but not of relative inequalities in obesity in many European countries over the past two decades. Our findings urge for a further understanding of the drivers of the increase in obesity in lower education groups particularly, and an equity perspective in population-based obesity prevention strategies.

Weight-related concerns and diet behaviors among urban young females: A cross-sectional study

Background:

Females are more likely than males to perceive themselves as too heavy, this has been explained in terms of the equation of “female beauty with extreme thinness.” Therefore, females are in general prone to develop unhealthy behaviors for weight management. Wrong weight control behaviors have significant health consequences.

Objectives:

To investigate the body weight concerns, body satisfaction, and weight control behaviors among young females and their association with age and socioeconomic status (SES).

Materials and Methods:

A cross-sectional study conducted in urban areas from a major city in South India. About 650 healthy unmarried females aged 15–25 years formed the study population. Self-reporting questionnaires were used to obtain relevant data. The categorical data were analyzed using Chi-square, correlation, and regression analyses by SPSS version 16.

Results:

Most overweight and obese subjects perceived themselves as overweight. Adolescents were more likely to report themselves as overweight. The perceived weight, body satisfaction, and weight control behaviors are influenced by weight status and age of the subjects. However, SES of the participants did not exhibit effect of others’ opinion about their weight and body satisfaction as well as weight management behaviors.

Conclusion:

The high prevalence of weight-related concerns suggests that all females should be reached with appropriate information and interventions. Healthy weight control practices need to be explicitly promoted and unhealthy practices discouraged. Young females need special attention toward weight management.

Socioeconomic inequalities of cardiovascular risk factors among manufacturing employees in the Republic of Ireland: A cross-sectional study

Objectives: To explore socioeconomic differences in four cardiovascular disease risk factors (overweight/obesity, smoking, hypertension, height) among manufacturing employees in the Republic of Ireland (ROI). Methods: Cross-sectional analysis of 850 manufacturing employees aged 18–64 years. Education and job position served as socioeconomic indicators. Group-specific differences in prevalence were assessed with the Chi-squared test. Multivariate regression models were explored if education and job position were independent predictors of the CVD risk factors. Cochran–Armitage test for trend was used to assess the presence of a social gradient. Results: A social gradient was found across educational levels for smoking and height. Employees with the highest education were less likely to smoke compared to the least educated employees (OR 0.2, [95% CI 0.1–0.4]; p < 0.001). Lower educational attainment was associated with a reduction in mean height. Non-linear differences were found in both educational level and job position for obesity/overweight. Managers were more than twice as likely to be overweight or obese relative to those employees in the lowest job position (OR 2.4 [95% CI 1.3–4.6]; p = 0.008). Conclusion: Socioeconomic inequalities in height, smoking and overweight/obesity were highlighted within a sub-section of the working population in ROI.

•

Exploring socioeconomic differences in four cardiovascular disease risk factors among manufacturing workers in Ireland.

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Cross-sectional study with 850 randomly selected employees aged 18–64 years.

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A social gradient was found across education levels for smoking and height.

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Employees with a higher education attainment were less likely to be hypertensive.

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Managers were more likely to be overweight or obese relative to the general working population.

Obesity and the potential reduction of social inequalities in mortality: evidence from 21 European populations

BACKGROUND

Obesity contributes considerably to the problem of health inequalities in many countries, but quantitative estimates of this contribution and to what extent it is modifiable are scarce. We identify the potential for reducing educational inequalities in all-cause and obesity-related mortality in 21 European populations, by modifying educational differences in obesity and overweight.

METHODS

Prevalence data and mortality data come from 21 European populations. Mortality rate ratios come from literature reviews. We use the population attributable fraction (PAF) to estimate the impact of scenario-based changes in the social distribution of obesity on educational inequalities in mortality.

RESULTS

An elimination of differences in obesity between educational groups would decrease relative inequality in all-cause mortality between those with high and low education by up to 12% for men and 42% for women. About half of the relative inequality in mortality could be reduced for some causes of death in several countries, often in southern Europe. Absolute inequalities in all-cause mortality would be reduced by up to 69 (men) and 67 (women) deaths per 100,000 person-years.

CONCLUSION

The potential reduction of health inequality by an elimination of social inequalities in obesity might be substantial. The reductions differ by country, cause of death and gender, suggesting that the priority given to obesity as an entry-point for tackling health inequalities should differ between countries and gender.

The role of answering behaviours on weight misreporting

BACKGROUND

Biases in self-reported weight are very common among young adults and adults. Although social norms are the most commonly accepted explanation for these misreports, corresponding evidence is scarce and conflict-ridden. An alternative explanation for biases in weight self-reports comes from answering behaviours; non-random rounding, formally an answering behaviour, has been found to play a significant role in several studies of weight misreporting. However, the presumably rich role of answering behaviours has seldom been explored. This study brings a second answering behaviour into the analysis: inconsistency.

METHODS

An inconsistency index was computed as an individual-level score from several questions across waves in the National Health and Nutrition Examination Survey. By regression analysis (N=3480 men and 1856 women) the simultaneous role of inconsistency and of non-random rounding on weight misreporting was explored.

RESULTS

Inconsistency was found to be associated with higher self-reported weights. Inconsistent individuals provided significantly different misreports, with women under-reporting 0.23[kg] (0.01-0.45) less and men over-reporting 0.42[kg] (0.02-0.82) more than their consistent counterparts. Inconsistency was found to play a simultaneous and substantially larger role than non-random rounding. This result was clearer among men than it was among women.

DISCUSSION

Although social norms are usually thought to be the central explanation of weight-biased misreports, there are other factors, such as answering behaviours, that might play a more influential role.

The validity of self-reported body mass index in a population-based osteoarthritis study

Background

Obesity is a well-known risk factor for osteoarthritis (OA). The majority of obesity research in OA is performed using self-reported BMI-data, however, its validity in persons with OA is unknown. The aim of this study was to compare the validity of self-reported body mass index (BMI) in persons with and without clinical osteoarthritis (OA) in a population-based survey.

Methods

Height and weight were self-reported, and thereafter measured in 600 persons with and without clinical OA according to the American College of Rheumatology-criteria (knees, hips and/or hands). We compared the differences between measured and self-reported heights, weights and BMIs (kg/m²) for the two groups and explored whether demographic/clinical factors were associated with inaccurate reporting in the OA patients using multivariate linear regression analyses.

Results

Mean (SD) age was 64 (8.7) years and 412 (69%) were women. Participants with clinical OA (n = 449) underreported their BMI to a greater extent than participants without clinical OA (n = 151) [mean (SD) difference 1.34 (1.68) kg/m² and 0.78 (1.40) kg/m² (p = 0.000), respectively]. There was a strong dose-dependent association between higher measured BMI and greater underreporting of BMI in multivariate analyses (BMI 25–29.99 kg/m²: B = 0.40, 95% CI, 0.06, 0.77), BMI ≥ 30 kg/m²: B = 1.30, 95% CI, 0.86, 1.75) in the clinical OA patients. A higher age as well as the time interval from self-reported to measured BMI-data were associated with inaccurate reporting.

Conclusions

Researchers using self-reported height and weight data should be aware of limited agreement with actual height and weight in overweight and obese individuals with clinical OA.

Maternal height and the risk of preterm birth and low birth weight: a systematic review and meta-analyses

OBJECTIVE

Preterm birth (PTB) and low birth weight (LBW) are the leading causes of neonatal morbidity and mortality, but the effect of maternal height on these outcomes continues to be debated. Our objective was to determine the relationships between maternal height and PTB and LBW.

DATA SOURCES

Medline and EMBASE were searched from their inceptions.

STUDY SELECTION

Studies with a reference group that assessed the effect of maternal height on PTB (< 37 weeks) and LBW (< 2500 grams) in singletons were included.

DATA EXTRACTION

Data were extracted independently by two reviewers.

DATA SYNTHESIS

Fifty-six studies were included involving 333 505 women. In the cohort studies, the unadjusted risk of PTB in short-statured women was increased (relative risk [RR] 1.23; 95% CI 1.11 to 1.37), as was the unadjusted risk of LBW (RR 1.81; 95% CI 1.47 to 2.23), although not all of the studies with adjusted data found the same association. Maternal tall stature was not associated with PTB (unadjusted RR 0.97; 95% CI 0.82 to 1.14), although LBW was decreased (unadjusted RR 0.56; 95% CI 0.46 to 0.69), but not in the adjusted data.

CONCLUSION

From our complete systematic review and meta-analyses, to our knowledge the first in this area, we conclude that short-statured women have higher unadjusted risks of PTB and LBW and tall women have approximately one half the unadjusted risk of LBW of women of reference height.

High degree of BMI misclassification of malnutrition among Swedish elderly population: Age-adjusted height estimation using knee height and demispan

BACKGROUND/OBJECTIVES

The degree of misclassification of obesity and undernutrition among elders owing to inaccurate height measurements is investigated using height predicted by knee height (KH) and demispan equations.

SUBJECTS/METHODS

Cross-sectional investigation was done among a random heterogeneous sample from five municipalities in Southern Sweden from a general population study 'Good Aging in Skåne' (GÅS). The sample comprised two groups: group 1 (KH) including 2839 GÅS baseline participants aged 60-93 years with a valid KH measurement and group 2 (demispan) including 2871 GÅS follow-up examination participants (1573 baseline; 1298 new), aged 60-99 years, with a valid demispan measurement. Participation rate was 80%. Height, weight, KH and demispan were measured. KH and demispan equations were formulated using linear regression analysis among participants aged 60-64 years as reference. Body mass index (BMI) was calculated in kg/m(2).

RESULTS

Undernutrition prevalences in men and women were 3.9 and 8.6% by KH, compared with 2.4 and 5.4% by standard BMI, and more pronounced for all women aged 85+ years (21% vs 11.3%). The corresponding value in women aged 85+ years by demispan was 16.5% vs 10% by standard BMI. Obesity prevalences in men and women were 17.5 and 14.6% by KH, compared with 19.0 and 20.03% by standard BMI. Values among women aged 85+ years were 3.7% vs 10.4% by KH and 6.5% vs 12.7% by demispan compared with the standard.

CONCLUSIONS

There is an age-related misclassification of undernutrition and obesity attributed to inaccurate height estimation among the elderly. This could affect the management of patients at true risk. We therefore propose using KH- and demispan-based formulae to address this issue.

Physical activity and awareness in breast screening attendees in Black Country, UK

This study aimed to determine the physical activity levels and awareness of the influence of physical activity and overweight/obesity on breast cancer risk among NHS breast screening programme (NHSBSP) attendees. One hundred and eighty-eight (white British = 95%; post-menopausal = 80%) attendees completed a demographic and anthropometric data questionnaire, International Physical Activity Questionnaire (IPAQ) and awareness of breast cancer risk factors questionnaire. IPAQ data were reported as continuous measures (MET-min · week(-1)) and as categorical variables (low, moderate and high activities). The highest median physical activity levels were reported in the domestic physical activity domain (756 MET-min · week(-1)). Most participants were categorized as 'moderately active' (45%), while 30% were classified in the 'high activity' and 25% as 'low activity' categories. Almost a third of participants (30%) reported no leisure-time physical activity and 83% reported no vigorous physical activity. There was high awareness of the effects of physical activity (75%) and obesity (80%) on breast cancer risk. No significant differences were found between physical activity categories and awareness that physical activity can reduce breast cancer risk (p > 0.05). However, compared with moderate and high activity categories, participants in the 'low activity' category were significantly more likely to respond that they thought they achieved recommended physical activity levels (p < 0.05). Participants who are unaware of their inadequate physical activity levels may have a less positive intention to increase physical activity levels. Practical strategies aimed to increase knowledge of the recommended physical activity guidelines and facilitate the achievement of these guidelines may be required for NHSBSP attendees.

Discrepant body mass index: behaviors associated with height and weight misreporting among US adolescents from the National Youth Physical Activity and Nutrition Study

BACKGROUND

The accuracy and reliability of self-reported height and weight among adolescents in the process of calculating BMI is usually subject to bias. The aim of this study was to determine whether over- and under-reporting of self-reported height and weight existed among US high school students by weight category; if so, to examine anthropometric, behavioral, and demographic factors associated with over- and under-reporting.

METHODS

Data were retrieved from the National Youth Physical Activity and Nutrition Study, 2010, a nationally representative sample (7160 students, grades 9-12). Analysis of variance was performed to determine any significant difference between weight categories in misreporting. Discriminant function analysis and sequential logistic regression were executed to detect behavioral and demographic predictors of reporting accuracy, respectively.

RESULTS

The mean over-reporting of height and under-reporting of weight were 1.1 cm and 1.020 kg, respectively, which underestimated BMI and BMI percentile by 0.671 and 2.734, respectively. Use of self-reported height and weight for BMI calculation overestimated prevalence of healthy weight by 3.8% and underestimated prevalence of obesity by 4.1%. Underweight students under-reported height and over-reported weight, whereas overweight and obese students over-reported height and under-reported weight. Reporting accuracy of females was significantly higher. Weight loss behaviors, both healthy and unhealthy, were associated with BMI underestimation, whereas fast foods and screen time were associated with overestimation.

CONCLUSION

Whenever possible, measuring height and weight is essential. However, because many studies must rely on self-reported values alone, additional research should examine the relationships between misreport of anthropometric data and lifestyle features in diverse adolescent samples to better interpret self-reported anthropometric data.

Agreement between self-reported and measured weight and height collected in general practice patients: a prospective study

Background

Self-reported weight and height is frequently used to quantify overweight and obesity. It is however, associated with limitations such as bias and poor agreement, which may be a result of social desirability or difficulties with recall. Methods to reduce these biases would improve the accuracy of assessment of overweight and obesity using patient self-report. The level of agreement between self-reported and measured weight and height has not been widely examined in general practice patients.

Methods

Consenting patients, presenting for care within four hour sessions, were randomly allocated to the informed or uninformed group. Participants were notified either a) prior to (informed group), or b) after (uninformed group) reporting their weight and height using a touchscreen computer questionnaire, that they would be measured. The differences in accuracy of self-report between the groups were examined by comparing mean differences, intraclass correlations (ICCs), Bland Altman plot with limits of agreement (LOAs) and Cohen’s kappa. Overall agreement was assessed using similar statistical methods.

Results

Of consenting participants, 32% were aged between 18–39 years, 42% between 40–64 years and 25% were 65 years and above. The informed group (n = 172) did not report their weight and height more accurately than the uninformed group (n = 160). Mean differences between self-reported and measured weight (p = 0.4004), height (p = 0.5342) and body mass index (BMI) (p = 0.4409) were not statistically different between the informed and uninformed group. Overall, there were small mean differences (−1.2 kg for weight, 0.8 for height and −0.6 kg/m² for BMI) and high ICCs (>0.9) between self-reported and measured values. A substantially high kappa (0.70) was obtained when using self-reported weight and height relative to measured values to quantify the proportion underweight, normal weight, overweight or obese. While the average bias of self-reported weight and height as estimates of the measured quantities is small, the LOAs indicate that substantial discrepancies occur at the individual level.

Conclusions

Informing patients that their weight and height would be measured did not improve accuracy of reporting. The use of self-reported weight and height for surveillance studies in this setting appears acceptable; however this measure needs to be interpreted with care when used for individual patients.

Validade de peso, altura e índice de massa corporal autorreferidos na população adulta de Brasília

OBJETIVO: Avaliar a validade do peso, altura e índice de massa corporal (IMC) autorreferidos em adultos de Brasília e identificar os fatores associados às diferenças entre os valores medidos e autorreferidos. MÉTODOS: Em amostra por conglomerados de 250 domicílios foram aferidos peso e altura de todos os adultos residentes, após entrevista. A concordância entre os parâmetros medidos e autorreferidos foi feita por Bland & Altman (B&A). Utilizou-se análise de variância múltipla e estimou-se a sensibilidade e especificidade para o excesso de peso (IMC ? 25 kg/m2), estratificado por anos de estudo e faixa etária. RESULTADOS: As entrevistas e mensurações foram feitas em 469 indivíduos. Os resultados de B&A mostram viés (diferença dos valores medidos e autorreferidos) não significativo para o peso (-0,17 kg, p = 0,1) e significativo para a altura (-1 cm, p < 0,001). Os limites de concordância (LC) foram amplos: de ±4 kg e de -6 cm a 4 cm. O viés do IMC foi de - 0,06 kg/m2 e não significativo (p = 0,08) e os LC de - 1,5 a +1,4 kg/m2. Observou-se que homens com IMC < 25 kg/m2 superestimam o peso, enquanto aqueles com sobrepeso e obesos o subestimam (p < 0,01). Homens com + 60a de idade (p = 0,037) e mulheres com < 12a de estudo (p < 0,01) superestimam a altura. A sensibilidade e a especificidade para o excesso de peso foram para homens e mulheres, respectivamente: 94% e 88%; 90% e 98%. A sensibilidade foi de 77% para mulheres acima de 60 anos, de 75% para mulheres com 9 a 11 anos de estudo, e a especificidade de 78% para homens entre 30 e 39 anos. CONCLUSÃO: Em Brasília, a altura autorreferida pode ser utilizada para subgrupos de homens < 60anos de idade e mulheres com + 12 anos de estudo. Homens com IMC adequado superestimam o peso corporal quando comparados com aqueles com sobrepeso ou obesos. As medidas autorreferidas prestam-se para acompanhamento populacional do excesso de peso.

Accuracy of self-reported weight and height and resulting body mass index among obese binge eaters in primary care: relationship with eating disorder and associated psychopathology

OBJECTIVE

This study assessed the accuracy of self-reported weight, height, and body mass index in obese patients with binge-eating disorder (DSM-IV-TR criteria) presenting at primary care clinics and tested whether the degree of inaccuracy was associated with demographic factors or eating disorder and depressive features.

METHOD

Sixty-six participants were interviewed using the Eating Disorder Examination interview, completed the Eating Disorder Examination Questionnaire and the Beck Depression Inventory, and had their height and weight measured between November 2007 and May 2009.

RESULTS

Self-reported and measured weight did not differ significantly, but participants significantly overestimated their height (P < .01), and this discrepancy resulted in a significantly lower self-reported than measured body mass index (P < .05). Discrepancy scores did not differ by eating disorder or depressive symptoms, sex, or ethnicity, although increasing age was associated with overestimation of height and underestimation of body mass index.

CONCLUSIONS

The findings suggest that obese patients with binge-eating disorder in primary care settings are reasonably accurate reporters of weight and height and that the degree of inaccuracy does not appear to be systematically related to eating disorder psychopathology or depressive features.

Truth be told: evidence of wheelchair users' accuracy in reporting their height and weight

OBJECTIVES

To examine whether wheelchair users' self-reports of height and weight differed significantly from direct measurements and whether weight category classifications differed substantially when based on self-reported or measured values.

DESIGN

Single group, cross-sectional analysis. Analyses included paired t tests, chi-square test, analysis of variance, and Bland-Altman agreement analyses.

SETTING

A university-based exercise lab.

PARTICIPANTS

Community-dwelling wheelchair users (N=125).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Participants' self-reported and measured height, weight, and body mass index.

RESULTS

Paired t tests revealed that there were significant differences between wheelchair users' self-reported and measured values for height (difference of 3.1±7.6cm [1.2±3.0in]), weight (-1.7±6.5kg [-3.6±14.2lb]), and BMI (-1.6±3.3). These discrepancies also led to substantial misclassification into weight categories, with reliance on self-reported BMI underestimating the weight status of 20% of the sample.

CONCLUSIONS

Our findings suggest that similar to the general population, wheelchair users are prone to errors when reporting their height and weight and that these errors may exceed those noted in the general population.

Can self-reported height and weight be used among people living with HIV/AIDS?

To assess the reliability and validity of self-reported height and weight in adults living with HIV/AIDS (ALWHA) we assessed 508 ALWHA of both genders on antiretroviral therapy. Height and weight were directly measured in a subsample. Sensitivity and specificity analysis were performed to determine the validity of self-reported measures. Bland-Altman's method was used to calculate the limits of agreement between values while reliability was assessed using intraclass coefficients. Regression equations were devised to determine actual measures from self-reported values. Mean differences among measured and self-reported weight were -0.96 kg for men and -0.54 kg for women. Mean height differences were less than 2 cm, yielding good reliability for body mass index (BMI). Overweight (BMI ≥ 25 kg/m(2)) diagnosis sensitivity was 90.6% and specificity was 81.2%. Corrected measures determined by regression equations had stronger correlation with self-reported values (r > 0.980). Self-reported height and weight showed good reliability and validity compared with directly measured height and weight. However, measures should be corrected whenever possible to achieve higher accuracy.

Who wants a slimmer body? The relationship between body weight status, education level and body shape dissatisfaction among young adults in Hong Kong

Background

Body shape dissatisfaction has been thought to have an indispensable impact on weight control behaviors. We investigated the prevalence of body shape dissatisfaction (BSD) and explored its association with weight status, education level and other determinants among young adults in Hong Kong.

Methods

Information on anthropometry, BSD, and socio-demographics was collected from a random sample of 1205 young adults (611 men and 594 women) aged 18-27 in a community-based household survey. BSD was defined as a discrepancy between current and ideal body shape based on a figure rating scale. Cross-tabulations, homogeneity tests and logistic regression models were applied.

Results

The percentages of underweight men and women were 16.5% and 34.9% respectively, and the corresponding percentages of being overweight or obese were 26.7% and 13.2% for men and women respectively. Three-quarters of young adults had BSD. Among women, 30.9% of those underweight and 75.5% of those with normal weight desired a slimmer body shape. Overweight men and underweight women with lower education level were more likely to have a mismatch between weight status and BSD than those with higher education level. After controlling for other determinants, underweight women were found to have a higher likelihood to maintain their current body shapes than other women. Men were found to be less likely to have a mismatch between weight status and BSD than women.

Conclusions

Overweight and obesity in men and underweight in women were prevalent among Hong Kong young adults. Inappropriate body shape desire might predispose individuals to unhealthy weight loss or gain behaviors. Careful consideration of actual weight status in body shape desire is needed in health promotion and education, especially for underweight and normal weight women and those with a low education level.

Socio-economic inequalities in overweight among adults in Turkey: a regional evaluation

Objective

Patterns of socio-economic inequalities in obesity and overweight have not been documented for Turkey. The present study aimed to describe educational and wealth-related inequalities for overweight in Turkey, taking a regional perspective.

Design

Cross-sectional self-reported data of the World Health Survey 2002 for Turkey were used. BMI ≥ 25·00 kg/m2 was considered as overweight. Respondents were classified according to education years and a wealth score derived from the availability of household assets. Logistic regression analysis was applied to assess the relationship between overweight and socio-economic factors. Analyses were stratified by sex and region (West, Mediterranean, Middle, Black Sea and East).

Setting

Turkey.

Subjects

Among the respondents 20 years and older, 3790 women and 4057 men had data on self-reported height and weight.

Results

Age-adjusted overweight prevalence was 48·4 % for women and 46·1 % for men. For men, education was not systematically related to overweight while overweight was significantly increased among the highest wealth groups. For women, the prevalence of overweight was highest for low-educated and middle-wealth groups. The size of the inequalities in overweight showed only small regional variations. In the East, however, overweight prevalence was more related to higher socio-economic position than in the other regions.

Conclusions

Socio-economic inequalities for overweight in Turkey are at a similar level as in most European countries, and especially comparable to Southern Europe. The smaller inequalities in the East correspond to the low level of socio-economic development in this part of the country. Prevention of overweight should focus on lower educational groups throughout the entire country and especially on low-educated women.

Underestimation of weight and its associated factors among overweight and obese adults in Pakistan: a cross sectional study

BACKGROUND

Weight loss is known to decrease the health risks associated with being overweight and obese. Awareness of overweight status is an important determinant of weight loss attempts and may have more of an impact on one's decision to lose weight than objective weight status. We therefore investigated the perception of weight among adults attending primary care clinics in Karachi, Pakistan, and compared it to their weight categories based on BMI (Body Mass Index), focusing on the underestimation of weight in overweight and obese individuals. We also explored the factors associated with underestimation of weight in these individuals.

METHODS

This was a cross sectional study conducted on 493 adults presenting to the three primary care clinics affiliated with a tertiary care hospital in Karachi, Pakistan. We conducted face to face interviews to gather data on a pre-coded questionnaire. The questionnaire included detail on demographics, presence of comorbid conditions, and questions regarding weight assessment. We measured height and weight of the participants and calculated the BMI. The BMI was categorized into normal weight, overweight and obese based on the revised definitions for Asian populations. Perception about weight was determined by asking the study participants the following question: Do you consider yourself to be a) thin b) just right c) overweight d) obese. We compared the responses with the categorized BMI. To identify factors associated with underestimation of weight, we used simple and multiple logistic regression to calculate crude odds Ratios (OR) and adjusted Odds Ratios (AOR) with 95% Confidence Intervals.

RESULTS

Overall 45.8% (n = 226) of the study participants were obese and 18% (n = 89) were overweight. There was poor agreement between self perception and actual BMI (Kappa = 0.24, SE = 0.027, p < 0.001). Among obese participants a large proportion (73%) did not perceive themselves as obese, although half (n = 102) of them thought they may be overweight. Among the overweight participants, half (n = 41) of them didn't recognize themselves as overweight. Factors associated with misperception of weight in overweight and obese participants were age ≥ 40 years (AOR = 3.4; 95% CI: 1.8-6.4), male gender (AOR = 2.97; 95% CI: 1.6-5.5), being happy with ones' weight (AOR = 6.4; 95% CI: 3.4-12.1), and not knowing one's ideal weight (AOR = 2.45, 95% CI: 1.10-5.47).

CONCLUSION

In this cross sectional survey, we observed marked discordance between the actual and perceived weight. Underestimation of individual weight was more common in older participants (≥ 40 years), men, participants happy with their weight and participants not aware of their ideal weight. Accurate perception of one's actual weight is critical for individuals to be receptive to public health messages about weight maintenance or weight loss goals. Therefore educating people about their correct weight, healthy weights and prevention of weight gain are important steps towards addressing the issue of obesity in Pakistan.

Challenging the role of social norms regarding body weight as an explanation for weight, height, and BMI misreporting biases: development and application of a new approach to examining misreporting and misclassification bias in surveys

Background

Cultural pressures to be thin and tall are postulated to cause people to misreport their body weight and height towards more socially normative (i.e., desirable) values, but a paucity of direct evidence supports this idea. We developed a novel non-linear approach to examining weight, height, and BMI misreporting biases and used this approach to examine the association between socially non-normative weight and misreporting biases in adults.

Methods

The Survey of Lifestyles, Attitudes, and Nutrition 2007 (SLÁN 2007), a nationally representative survey of the Republic of Ireland (N = 1942 analyzed) was used. Self-reported weight (height) was classified as under-reported by ≥2.0 kg (2.0 cm), over-reported by ≥2.0 kg (2.0 cm), or accurately reported within 2.0 kg (2.0 cm) to account for technical errors of measurement and short-term fluctuations in measured weight (height). A simulation strategy was used to define self-report-based BMI as under-estimated by more than 1.40 kg/m², over-estimated by more than 1.40 kg/m², or accurately estimated within 1.40 kg/m². Patterns of biases in self-reported weight, height, and BMI were explored. Logistic regression was used to identify factors associated with mis-estimated BMI and to calculate adjusted odds ratios (AOR) and 99% confidence intervals (99%CI).

Results

The patterns of bias contributing the most to BMI mis-estimation were consistently, in decreasing order of influence, (1) under-reported weight combined with over-reported height, (2) under-reported weight with accurately reported height, and (3) accurately reported weight with over-reported height. Average bias in self-report-based BMI was -1.34 kg/m² overall and -0.49, -1.33, and -2.66 kg/m² in normal, overweight, and obese categories, respectively. Despite the increasing degree of bias with progressively higher BMI categories, persons describing themselves as too heavy were, within any given BMI category, less likely to have under-estimated BMI (AOR 0.5, 99%CI: 0.3-0.8, P < 0.001), to be misclassified in a lower BMI category (AOR 0.3, 99%CI: 0.2-0.5, P < 0.001), to under-report weight (AOR 0.5, 99%CI: 0.3-0.7, P < 0.001), and to over-report height (OR 0.7, 99%CI: 0.6-1.0, P = 0.007).

Conclusions

A novel non-linear approach to examining weight, height, and BMI misreporting biases was developed. Perceiving oneself as too heavy appears to reduce rather than exacerbate weight, height, and BMI misreporting biases.

Self-reported weight and height: implications for left ventricular hypertrophy detection. An Italian multi-center study

We examined the difference between self-reported and measured body size values and their impact on detection of left ventricular hypertrophy (LVH) by echocardiographic LV mass indexation. A total of 1963 subjects referred by their practitioners for routine echocardiographic examination to nine outpatient echocardiographic laboratories across Italy were included in the study. Left ventricular hypertrophy was defined according to two gender- specific criteria as: A) Left ventricular mass (LVM) index ≥49 g/h(2.7) in men and ≥45 g/h(2.7) in women; B) LVM index ≥125 g/m(2) in men and ≥110 g/m(2) in women. Prevalence of LVH was calculated by indexing LVM to both self-reported and measured anthropometric values. In the whole population, LVH tended to be underestimated by self-reported values by 5.4% according to criterion A (48.5% vs. 53.9%, p < 0.001) and by 1.2% according to criterion B (29.6% vs. 30.8%, p < 0.01); similar findings were observed in the hypertensive subgroup encompassing one-half of the sample. Underestimation of LVH was more pronounced in older patients than in younger patients: 8.6% vs. 3.2% (p < 0.001) by criterion A, 3.1% vs. 0.1% (p < 0.001) by criterion B, in women than in men (8.6% vs. 3.3% (p < 0.001) by criterion A and 1.8% vs. 0.5% (p < 0.01) by criterion B. In a sample of outpatients attending echocardiographic laboratories, LVH is misclassified when left ventricular mass is normalized to self-reported weight and height. The error is related to the clinical characteristics of patients and is more pronounced when LVM is normalized to height(2.7).

Validity of self-reported height, weight, and body mass index of the Korea Youth Risk Behavior Web-based Survey questionnaire

OBJECTIVES

Self-reported anthropometric values, such as height and weight, are used to calculate body mass index (BMI) and assess the prevalence of obesity among adolescents. The aim of this study was to evaluate the validity of self-reported height, weight, and BMI of the Korea Youth Risk Behavior Web-based Survey questionnaire.

METHODS

A convenience sample of 137 middle school students and 242 high school students completed a self-administered questionnaire in 2008. Body height and weight were directly measured after self-reported values were obtained from the questionnaire survey. Sensitivity, specificity, and kappa statistics were computed in order to evaluate the validity of the prevalence of obesity (BMI ≥ 95th percentile or ≥ 25 kg/m(2)) based on self-reported data.

RESULTS

Self-reported weight and BMI tended to be underestimated. Self-reported height tended to be overestimated among middle school females and high school males. Obese adolescents tended to underestimate their weight and BMI and overestimate their height more than non-obese adolescents. The prevalence estimate of obesity based on self-reported data (10.6%) was lower than that based on directly measured data (15.3%). The estimated sensitivity of obesity based on self-reported data was 69.0% and the specificity was 100.0%. The value of kappa was 0.79 (95% confidence interval, 0.70-0.88).

CONCLUSIONS

This study demonstrated that self-reported height and weight may lead to the underestimation of BMI and consequently the prevalence of obesity. These biases should be taken into account when self-reported data are used for monitoring the prevalence and trends of obesity among adolescents nationwide.

Waist circumference is an independent correlate of errors in self-reported BMI

Although there are issues of reporting bias surrounding the use of self-reported BMI, it is frequently the method employed to establish the prevalence of obesity. The goal of this study was to assess whether, independently of measured BMI, waist circumference (WC) was associated with the magnitude of the difference between self-reported and measured BMI within a large sample of European-American (EA) and African-American (AA) adults. Self-reported height and weight, and measured height, weight, and WC were collected on 12,809 adults (61% women, 66% EA) aged 18-65 years. Mean negative BMI differences (self-reported minus measured BMI) were identified in all race-by-sex groups (AA men: -0.55; EA men: -0.63; AA women: -0.91; EA women: -0.67). WC was negatively associated with the BMI difference such that a higher WC was associated with greater under-reporting of BMI. However, after adjusting for age and measured BMI, WC was positively associated with the BMI difference in all race-by-sex groups. These results suggest that WC could be useful in gaining an insight into people's awareness of their own body size and fatness.

Validity of self-reported height and weight in a Korean population

BACKGROUND

Accessible public information on self-reported height and weight is not widely used in studies of obesity, mainly because of the questionable validity of body mass index (BMI) values calculated from these data. To assess the utility of self-reported measurement, we compared self-reported and standard measurements of height and weight in a Korean population that is leaner than Western populations.

METHODS

A cross-sectional comparison of self-reported and measured height and weight was conducted among a population of participants in a cancer screening program. A total of 557 men and 1010 women aged 30 to 70 years were included in the current analysis.

RESULTS

Self-reported height was higher than measured values in both men and women. Self-reported weight was higher than measured weight in women, but was not different in men. BMI calculated from measured values was higher than BMI derived from self-reported height and weight among men. Younger age was a predictor of accuracy in self-reported height, and higher weight and BMI were predictors of under-reporting of weight. The prevalence of obesity based on self-reported values was lower than the true prevalence of obesity. With respect to classifying individuals as obese, the specificity and sensitivity of BMI calculated from self-reported values were very high for both sexes.

CONCLUSIONS

Self-reported height and weight were reasonably valid in this study population.

Do socioeconomic factors shape weight and obesity trajectories over the transition from midlife to old age? Results from the French GAZEL cohort study

BACKGROUND

Obesity is a contemporary epidemic that does not affect all age groups and sections of society equally.

OBJECTIVE

The objective was to examine socioeconomic differences in trajectories of body mass index (BMI; in kg/m(2)) and obesity between the ages of 45 and 65 y.

DESIGN

A total of 13,297 men and 4532 women from the French GAZEL (Gaz de France Electricité de France) cohort study reported their height in 1990 and their weight annually over the subsequent 18 y. Changes in BMI and obesity between ages 45 and 49 y, 50 and 54 y, 55 and 59 y, and 60 and 65 y as a function of education and occupational position (at age 35 y) were modeled by using linear mixed models and generalized estimating equations.

RESULTS

BMI and obesity rates increased between the ages of 45 and 65 y. In men, BMI was higher in unskilled workers than in managers at age 45 y; this difference in BMI increased from 0.82 (95% CI: 0.66, 0.99) at 45 y to 1.06 (95% CI: 0.85, 1.27) at 65 y. Men with a primary school education compared with those with a high school degree at age 45 y had a 0.75 (95% CI: 0.51, 1.00) higher BMI, and this difference increased to 1.32 (95% CI: 1.03,1.62) at age 65 y. Obesity rates were 3.35% and 7.68% at age 45 y and 9.52% and 18.10% at age 65 y in managers and unskilled workers, respectively; the difference in obesity increased by 4.25% (95% CI: 1.87, 6.52). A similar trend was observed in women.

CONCLUSIONS

Weight continues to increase in the transition between midlife and old age; this increase is greater in lower socioeconomic groups.

Validity and reliability of self-reported weight, height and body mass index from telephone interviews

The objective of this study was to examine factors associated with the validity of self-reported anthropometric measures. The authors selected 726 adults, aged 40 or older, living in the greater metropolitan region of São Paulo, Brazil. Self-reported weights and heights obtained from telephone interviews were compared to values measured directly by means of a multicenter survey. Mean differences (±SD) between self-reported and measured weights and heights among men were 0.54 (±0.30kg) and 1.98 (±0.31cm); while among women, they were -0.48 (±0.23kg) and 3.97 (±0.28cm), respectively. Sensitivity and specificity to diagnose obesity were 71% and 98% for males, and 78% and 96%, for females, respectively. There was good agreement between measured and self-reported weights and body mass index (BMI) among both sexes, however, self-reported height was less reliable. Self-reported weight and height obtained from telephone interviews are valid to estimate the obesity prevalence in this population, although systematic bias was found. Thus, it is desirable that researchers develop their own equations depending on the population being studied.

Comparative appraisal of educational inequalities in overweight and obesity among adults in 19 European countries

BACKGROUND

In Western societies, a lower educational level is often associated with a higher prevalence of overweight and obesity. However, there may be important international differences in the strength and direction of this relationship, perhaps in respect of differing levels of socio-economic development. We aimed to describe educational inequalities in overweight and obesity across Europe, and to explore the contribution of level of socio-economic development to cross-national differences in educational inequalities in overweight and obese adults in Europe.

METHODS

Cross-sectional data, based on self-reports, were derived from national health interview surveys from 19 European countries (N = 127 018; age range = 25-44 years). Height and weight data were used to calculate the body mass index (BMI). Multivariate regression analysis was employed to measure educational inequalities in overweight and obesity, based on BMI. Gross domestic product (GDP) per capita was used as a measure of level of socio-economic development.

RESULTS

Inverse educational gradients in overweight and obesity (i.e. higher education, less overweight and obesity) are a generalized phenomenon among European men and even more so among women. Baltic and eastern European men were the exceptions, with weak positive associations between education and overweight and obesity. Educational inequalities in overweight and obesity were largest in Mediterranean women. A 10 000-euro increase in GDP was related to a 3% increase in overweight and obesity for low-educated men, but a 4% decrease for high-educated men. No associations with GDP were observed for women.

CONCLUSION

In most European countries, people of lower educational attainment are now most likely to be overweight or obese. An increasing level of socio-economic development was associated with an emergence of inequalities among men, and a persistence of these inequalities among women.

Prevalence of educational inequalities in obesity between 1970 and 2003 in France

This paper examines trends in obesity rates and education-related absolute and relative inequalities in obesity over the last 40 years in France. Data are drawn from the French Decennial Health Surveys of 1970, 1980, 1991 and 2003. The difference in obesity rates between the least- and most-educated, the Slope Index of Inequality, is used to estimate absolute inequalities in obesity. The ratio of the corresponding rates, the Relative Index of Inequality, reveals the relative inequalities in obesity. Obesity rates were similar in men and women, but educational inequalities were greater in women. Obesity rates were similar over the first three surveys but increased for all in the 2003 survey. This increase was accompanied by increases in absolute inequalities in men (P = 0.04) from a Slope Index of Inequality of 4.80% (95% confidence interval [CI] = 2.27, 7.32) to 8.64% (95% CI = 5.97, 11.32) and women (P = 0.004) from 8.90% (95% CI = 6.18, 11.63) to 14.57% (95% CI = 11.83, 17.32). Relative inequalities in obesity remained stable over the 40 years. Recent increase in obesity rates in France is accompanied by increases in absolute education-related inequalities, while relative inequalities have remained stable; this suggests that obesity rates have increased at a much faster rate in the low-education groups.

Unawareness of weight and height--the effect on self-reported prevalence of overweight in a population-based study

OBJECTIVE

Self-reported height and weight are commonly used to estimate body mass index. The present study aims to identify the characteristics of participants who reported not to know their height or weight and to evaluate the consequence of these missing data on the estimates of the prevalence of body mass index categories.

DESIGN AND PARTICIPANTS

We evaluated 1492 adults, aged 18-92 years, who were selected using random digit dialing. During a general interview, participants were asked to report their current height and weight and actual anthropometrical measurements were obtained as part of a subsequent physical examination. We classified as unaware subjects who reported not to know their height or weight.

RESULTS

In this sample, 185 (12.4%) subjects reported not to know their height or weight (19.6% of females and 6.3% of males, p < 0.001). Women unaware of their weight or height were older, less educated, overweight or obese, never smoker and more frequently reported no regular physical exercise practice. In men, only ex-smokers were significantly less aware of their weight or height. In women, the prevalence of obesity using measured data was 25.3%, decreasing to 22.2% when considering only participants aware of their weight and height. Using self-reported data the obesity prevalence, in females, was 15.0%.

CONCLUSION

A large proportion of adults, mainly women and older persons, reported not to know their weight and height and the exclusion of those participants results in differential errors depending on the actual values. The exclusion of participants unaware of their weight or height is an additional source of bias that decreases the sensitivity in detecting obesity and underestimates the real problem, namely in the older population.

Ethnic differences in self-reported and measured obesity

As use of self-reported data to classify obesity continues, ethnic differences in reporting errors remain unclear. The objective of this study is to elucidate misreporting disparities between African Americans (AAs) and European Americans (EAs). The Pennington Center Longitudinal Study (PCLS) is an ongoing investigation of environmental, behavioral, and biological factors associated with obesity, diabetes, and other common diseases. Self-reported and measured height and weight were collected during initial screening for eligibility in various studies by telephone and clinic visits. All ethnicity-sex groups (15,656 adults aged 18-65 years, 53% obese, 34% AA, 37% men) misreported heights and weights increasingly as measured values increased (P < 0.0001). More AA vs. EA women (P < 0.001) misreported height and weight, but more EA vs. AA men misreported their weight (P < 0.02). Obesity was underestimated more in AA vs. EA women (self-reported - measured prevalence = -4.0% (AA) vs. -2.6% (EA), P < 0.0001), but less in AA vs. EA men (-3.2% (AA) vs. -4.2% (EA), P < 0.0001)). With measured obesity prevalence equalized at 53% in all groups, the self-reported obesity prevalence in women was 50.4% (AA) vs. 49.6% (EA), and in men 49.8% (AA) vs. 47.3 (EA). Underestimation in women was -2.6% (AA) vs. -3.4% (EA); in men it was -3.2% (AA) vs. -5.7% (EA), P < 0.003. Self-reported height and weight portend underestimation of obesity prevalence and the effect varies by ethnicity and gender. However, comparisons depend on the true prevalence within ethnicity-gender groups. After controlling for obesity prevalence, disparity in underestimation was greater in EA than in AA men (P < 0.003) but not women.

The relation between body mass index, mental health, and functional disability: a European population perspective

OBJECTIVE

To examine the association between body mass, mental disorders, and functional disability in the general population of 6 European countries.

METHOD

Data (n = 21 425) were derived from the European Study on the Epidemiology of Mental Disorders (ESEMeD). The third version of the Composite International Diagnostic Interview was administered to assess mental disorders (mood, anxiety, and alcohol disorders) according to the Diagnostic Statistical Manual of Mental Disorders-fourth edition, body mass index (BMI) (kg/m(2), based on self-reported height and weight), and functional disability in the previous 30 days, assessed with the World Health Organization Disablement Assessment Scale-second version.

RESULTS

About 3% of the respondents were underweight (BMI < 18.5 kg/m(2)), 53% had normal weight (BMI 18.5 to 24.9 kg/m(2)), 33% were overweight (BMI 25 to 29.9 kg/m(2)), and the remaining 12% met criteria for obesity (BMI >or= 30.0 kg/m(2)). Compared with individuals of normal weight, obese individuals were more likely to have mood (OR 1.3; 95%CI, 1.0 to 1.8) or more than one mental disorder (OR 1.4; 95%CI, 1.0 to 2.2). BMI had no impact on work loss days, whereas mental disorders had a considerable effect on work loss days.

CONCLUSIONS

This is the first cross-national study investigating the role between BMI, mental disorders, and functional disability in the general population. Being overweight or obese is a common condition in the 6 ESEMeD countries. Although there is a moderate association between obesity and mental disorders, BMI did not independently influence functional disability.

Validity of a self-reported measure of familial history of obesity

BACKGROUND

Familial history information could be useful in clinical practice. However, little is known about the accuracy of self-reported familial history, particularly self-reported familial history of obesity (FHO).

METHODS

Two cross-sectional studies were conducted. The aims of study 1 was to compare self-reported and objectively measured weight and height whereas the aims of study 2 were to examine the relationship between the weight and height estimations reported by the study participants and the values provided by their family members as well as the validity of a self-reported measure of FHO. Study 1 was conducted between 2004 and 2006 among 617 subjects and study 2 was conducted in 2006 among 78 participants.

RESULTS

In both studies, weight and height reported by the participants were significantly correlated with their measured values (study 1: r = 0.98 and 0.98; study 2: r = 0.99 and 0.97 respectively; p < 0.0001). Estimates of weight and height for family members provided by the study participants were strongly correlated with values reported by each family member (r = 0.96 and 0.95, respectively; p < 0.0001). Substantial agreement between the FHO reported by the participants and the one obtained by calculating the BMI of each family members was observed (kappa = 0.72; p < 0.0001). Sensitivity (90.5%), specificity (82.6%), positive (82.6%) and negative (90.5%) predictive values of FHO were very good.

CONCLUSION

A self-reported measure of FHO is valid, suggesting that individuals are able to detect the presence or the absence of obesity in their first-degree family members.

The predictive value of different socio-economic indicators for overweight in nine European countries

OBJECTIVES

To assess which socio-economic indicator best predicts overweight in the European Union: educational attainment, occupational class or household income.

SETTING

The prevalence of overweight is strongly related to socio-economic position. The relative importance of different socio-economic dimensions is uncertain, and might vary between countries.

DESIGN AND SUBJECTS

Cross-sectional self-report data of the European Community Household Panel were obtained from nine countries (n 52,855; age 25-64 years). Uni- and multivariate regression analyses were employed to predict overweight (BMI >or= 25 kg/m2) in relationship to socio-economic indicators. Occupational class was measured using the new European Socioeconomic Classification.

RESULTS

Large socio-economic differences in overweight were observed in all countries, especially for women. For both sexes, a low educational attainment was the strongest predictor of overweight. After controlling for education, overweight was negatively related to household income in women, but positively in men. Similar patterns were found for occupational class. For women, but not for men, educational inequalities in overweight were generally greater in Southern European countries. A similar pattern of inequalities in overweight was observed for all ages between 25 and 64 years.

CONCLUSIONS

Across Europe, overweight was more strongly and more consistently related to educational attainment than to occupational class or household income. People with lower educational attainment should be a specific target group for programmes and policies that aim to prevent overweight.

Is there an intrauterine influence on obesity? Evidence from parent child associations in the Avon Longitudinal Study of Parents and Children (ALSPAC)

BACKGROUND

It has been suggested that increasing obesity levels in young women lead to intrauterine environments that, in turn, stimulate increased obesity among their offspring, generating an intergenerational acceleration of obesity levels. If this mechanism is important, the association of maternal body mass index (BMI) with offspring BMI should be stronger than the association of paternal with offspring BMI.

OBJECTIVE

To compare the relative strengths of association of maternal and paternal BMI with offspring BMI at age 7.5, taking into account the possible effect of non-paternity.

METHODS

We compared strength of association for maternal-offspring and paternal-offspring BMI for 4654 complete parent-offspring trios in the Avon Longitudinal Study of Parents and Children (ALSPAC), using unstandardised and standardised regression analysis. We carried out a sensitivity analysis to investigate the influence of non-paternity on these associations.

RESULTS

The strength of association between parental BMI and offspring BMI at age 7.5 was similar for both parents. Taking into account correlations between maternal and paternal BMI, performing standardised rather than unstandardised regression and carrying out a sensitivity analysis for non-paternity emphasised the robustness of the general similarity of the associations. The associations between high parental BMI (top decile) and offspring BMI are also similar for both parents.

CONCLUSION

Comparison of mother-offspring and father-offspring associations for BMI suggests that intergenerational acceleration mechanisms do not make an important contribution to levels of childhood BMI within the population. Associations at later ages and for different components of body composition now require study.

A comparison of direct vs. self-report measures for assessing height, weight and body mass index: a systematic review

Obesity is a rapidly increasing public health problem, with surveillance most often based on self-reported values of height and weight. We conducted a systematic review to determine what empirical evidence exists regarding the agreement between objective (measured) and subjective (reported) measures in assessing height, weight and body mass index (BMI). Five electronic databases were searched to identify observational and experimental studies on adult populations over the age of 18. Searching identified 64 citations that met the eligibility criteria and examined the relationship between self-reported and directly measured height or weight. Overall, the data show trends of under-reporting for weight and BMI and over-reporting for height, although the degree of the trend varies for men and women and the characteristics of the population being examined. Standard deviations were large indicating that there is a great deal of individual variability in reporting of results. Combining the results quantitatively was not possible because of the poor reporting of outcomes of interest. Accurate estimation of these variables is important as data from population studies such as those included in this review are often used to generate regional and national estimates of overweight and obesity and are in turn used by decision makers to allocate resources and set priorities in health.

Los sistemas de género y/en la Encuesta Nacional de Salud

OBJECTIVE

To analyze the Spanish National Health Interview Survey (NHIS) from a gender perspective, with special emphasis on gender division of labor.

METHOD

We analyzed the 2003 Spanish NHIS from the perspective of the levels of gender observation, with gender understood as: a) the basis of social norms (responsibilities by sex, health risks, and problems related to masculine/feminine roles); b) the organizer of the social structure: gender division of labor, work overload, vertical/horizontal segregation, time spent in activities according to social times, access to resources), and c) a component of individual identity (conflicts due to multiple roles, body image dissatisfaction, self-esteem, self-perceived recognition of the work performed, assimilation of the sexual gender role, sex differences in health conditions).

RESULTS

The Spanish NHIS is centered on the main provider, referred to in masculine grammatical form. Gender division of domestic labor is identified only by a general question. When using the concept of main activity for productive or reproductive work, the survey requires respondents to evaluate them and select only one, thus losing information and hampering analysis of the impact of an overload of work on health. Information on time used for reproductive work and leisure is not solicited. Assaults (intentional) and accidents (non-intentional) are combined in the same question, thus preventing research on gender-related violence.

CONCLUSIONS

The Spanish NHIS includes the variable of sex, but its more descriptive than analytic focus limits gender analysis. The survey allows specific circumstances of employment-related inequalities between sexes to be measured, but does not completely allow other indicators of gender inequalities, such as the situation of housewives or work overload, to be measured.

How valid are self-reported height and weight? A comparison between CATI self-report and clinic measurements using a large cohort study

OBJECTIVE

To examine the relationship between self-reported and clinical measurements for height and weight in adults aged 18 years and over and to determine the bias associated with using household telephone surveys.

METHOD

A representative population sample of adults aged 18 years and over living in the north-west region of Adelaide (n = 1,537) were recruited to the biomedical cohort study in 2002/03. A computer-assisted telephone interviewing (CATI) system was used to collect self-reported height and weight. Clinical measures were obtained when the cohort study participants attended a clinic for biomedical tests.

RESULT

Adults over-estimated their height (by 1.4 cm) and under-estimated their weight (by 1.7 kg). Using the self-report figures the prevalence of overweight/ obese was 56.0% but this prevalence estimate increased to 65.3% when clinical measurements were used. The discrepancy in self-reported height and weight is partly explained by 1) a rounding effect (rounding height and weight to the nearest 0 or 5) and 2) older persons (65+ years) considerably over-estimating their height.

CONCLUSION

Self-report is important in monitoring overweight and obesity; however, it must be recognised that prevalence estimates obtained are likely to understate the problem.

IMPLICATIONS

The public health focus on obesity is warranted, but self-report estimates, commonly used to highlight the obesity epidemic, are likely to be underestimations. Self-report would be a more reliable measure if people did not round their measurements and if older persons more accurately knew their height.

Psychosocial correlates of adolescent obesity, 'slimming down' and 'becoming obese'

PURPOSE

(a) To examine how self-reported well-being, weight-related concerns, self-image, peer relationships and psychiatric disorders are associated with obesity at ages 11 and 15 years. (b) To identify and describe those who "slim down" (become nonobese) or "become obese".

METHODS

A cohort of 2127 school pupils was surveyed at ages 11 and 15 years. At each age, those with body mass index above the 95th percentile for age and gender were categorized as obese. Characteristics associated with obesity, "slimming down" and "becoming obese" were examined using ANOVA and chi-square procedures for univariate, and logistic regression for multivariate analyses.

RESULTS

At age 11, 9.6% (males) and 10.5% (females) were obese, compared with 10.5% (males) and 11.6% (females) at age 15. "Slimming down" occurred for 3.5% of the total sample, whereas 4.5% "became obese." Obesity was associated with significant but small differences in low mood (males at 11) and self-esteem (males at 11, females at both ages), and reduced rates of behavior disorders (data on psychiatric disorders available only at age 15). Obesity was associated with weight-related worries, dieting, and poor self-rated appearance, but not most measures of peer relationships, except that obese 11-year-olds experienced greater victimization, partly accounting for their poorer well-being. In comparison with the continuously nonobese, those who "became obese" had lower prior self-esteem and greater victimization, but improvements in well-being and relative reductions in victimization by age 15. "Slimming down" was related to neither prior nor subsequent well-being in comparison with continual obesity, but was associated with better age 15 mood in comparison with continual nonobesity.

CONCLUSIONS

Although overweight was fairly stable, there were shifts in and out of the obese category during adolescence. Obesity during this life-stage, though strongly related to worries about putting on weight and self-report dieting, was associated with only small differences in psychological well-being.

Age at menarche and adult BMI in the Aberdeen children of the 1950s cohort study

BACKGROUND

Few studies have examined whether the inverse association of age at menarche with adult body mass index (BMI) is due to the tendency of BMI to track between childhood and adult life, with childhood BMI playing a causal role in determining age at menarche.

OBJECTIVE

The objective was to investigate whether the association of younger age at menarche with a high BMI and increased likelihood of obesity in middle age is due to confounding with early childhood BMI.

DESIGN

In a historical cohort of 3743 Scottish females born between 1950 and 1955, height and weight were measured in early childhood, and age at menarche and height and weight in middle age were obtained by questionnaire.

RESULTS

The age-adjusted change in mean adult BMI per additional year of age at menarche was -0.64 (95% CI: -0.78, -0.50). Adjustment for childhood BMI measured between 4 and 6 y reduced this value to -0.57 (-0.71, -0.43). Adjustment for childhood and adult social class, parity, smoking, and alcohol intake had little effect. The odds ratio for being obese compared with not being obese in adulthood was 0.82 (0.76, 0.86) per 1-y increase in age at menarche and was unchanged by adjustment for childhood BMI and other covariates.

CONCLUSIONS

The inverse association of age at menarche with BMI and obesity in middle age is not explained by confounding by early childhood BMI. Instead, age at menarche may simply be a proxy marker for the pace of sexual maturation, which itself leads to differences in adiposity (and BMI) in the peripubertal period that track into adult life.

Obesity, weight status and employability: empirical evidence from a French national survey

We investigate the relationship between employability and obesity, particularly how obesity and overweight are associated with the percentage of working years spent unemployed and the ability to regain employment. Data for adults who responded to the 2003 Decennial Health Survey collected by the French National Institute of Statistics and Economic Studies revealed that the percentage of time spent unemployed during working years is significantly higher for each kg/m2 deviation from the mean body mass index (BMI) attained at age 20 and that the probability of regaining employment after a period of unemployment is much lower.

Accuracy of self-reported waist and hip measurements in 4492 EPIC-Oxford participants

OBJECTIVE

To assess the accuracy of self-reported waist and hip circumferences and the waist-to-hip ratio (WHR) by comparison with measured waist and hip circumferences and WHR in a sample of middle-aged men and women.

DESIGN

Analysis of measured and self-reported waist and hip data from participants in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford).

PARTICIPANTS

Four thousand four hundred and ninety-two British men and women aged 35-76 years.

RESULTS

Spearman's rank correlation coefficients between measured and self-reported waist, hip and WHR were 0.80, 0.74 and 0.44, respectively, for men and 0.83, 0.86 and 0.62 for women. Waist was underestimated, on average, by 3.1 (standard deviation (SD) 5.6) cm in men and 1.9 (SD 5.4) cm in women. The extent of underestimation was greater in participants with larger waists, older participants and women with greater body mass index (BMI). Hip was underestimated by a mean of 1.8 (SD 4.9) cm in men and 1.2 (SD 4.5) cm in women; the extent of underestimation was greater in participants with larger hip circumference and older participants. On average, WHR was underestimated by less than 2% by men and women; the extent of underestimation was greater among those with larger WHR, older people and those with greater BMI. Using self-reported values, the proportion of classification to the correct tertile was over 65% for waist and hip measurements. For WHR this proportion was 50% among men and 60% among women.

CONCLUSIONS

Self-reported waist and hip measurements in EPIC-Oxford are sufficiently accurate for identifying relationships in epidemiological studies.

Predictors of the accuracy of self-reported height and weight in adolescent female school students

OBJECTIVE

The authors investigated predictors of the accuracy of self-reported values of body weight and height in adolescent females.

METHOD

Self-reported and measured weight and height values were obtained for 683 school students aged 11-18 years. Predictors of accuracy were determined for self-reported weight, height, and body mass index (BMI; based on self-reported values).

RESULTS

Self-reported weight was underestimated. This was most likely for students with higher BMI values and actual weight. Younger, early pubertal and premenarcheal students were most likely to underestimate their height whereas older, postmenarcheal (more than 3 years) students were most likely to overestimate their height. The more exercise reported, the more accurate the height estimation. This translates to a greater underestimation of BMI as adolescents become older, have a longer duration since menarche, and exercise more.

DISCUSSION

When accurate information is required, clinicians should measure height and weight, particularly if the adolescent female is perimenarcheal or appears to differ from population averages for height and weight.

Validade de peso e estatura informados e índice de massa corporal: estudo pró-saúde

OBJETIVO: Avaliar a validade do peso e da estatura informados e do índice de massa corporal (IMC). MÉTODOS: Foram estudados 3.713 funcionários públicos de uma universidade no Rio de Janeiro, participantes da Fase 1 de um estudo longitudinal. As informações foram obtidas por meio de questionário auto-preenchível; as aferições foram realizadas após a aplicação. Para avaliar as diferenças entre os parâmetros aferidos e informados, utilizou-se o teste t pareado de Student, gráficos de Bland & Altman e o coeficiente de correlação intraclasse (CCIC). Estimou-se a sensibilidade e a especificidade das várias categorias do IMC. RESULTADOS: Houve alta concordância entre a aferição e a informação do peso (CCIC=0,977) e da estatura (CCIC=0,943). A sensibilidade do IMC, em suas várias categorias, variou em torno de 80%, e a especificidade foi próxima de 92%. Houve tendência leve e uniforme à subestimação do peso informado e à superestimação da estatura informada em ambos os sexos. CONCLUSÕES: As informações relatadas e aferidas de peso e estatura apresentaram boa concordância e validade; em populações similares, que disponham de recursos escassos, é possível utilizar dados informados ao invés de valores aferidos.

[Study of validity in self-reported weight and height among pregnant women treated at municipal maternity hospitals in Rio de Janeiro, Brazil]

The main objectives of this article are the assessment of agreement between measure-based and report-based information on weight and height, besides the identification of the main characteristics related to 150 pregnant women who could report (versus could not report) their pre-gestational weight, weight at delivery, and height. According to the results, report-based information on previous weight is close to the measure-based information (Pearson coefficient correlation 0.96 and intra-class correlation 0.92; p < 0.05), with the same occurring for weight at delivery (Pearson coefficient correlation 0.96 and intra-class correlation 0.95; p < 0.05). Nevertheless, linear regression analysis detects that this relationship is troublesome for the height variable (beta0 = 45.5 and beta1 = 0.71; p < 0.05), and therefore the report-based information for height must be used cautiously when the measure-based values are not available. In relation to the characterization of the group of pregnant women who did not inform the three measures (n = 141), these women have the least schooling (63.9%), did not attend or attended fewer prenatal appointments (64.3%), and entered the prenatal program later, when they were already in the second or third trimester (59.3%).