Socioeconomic Gradient In Obesity Research Articles

Socioeconomic Status and Obesity.

Obesity is a pervasive public health problem that causes debilitating complications across the life course. One opportunity for preventing the onset of obesity is to focus on its social determinants. Socioeconomic status (SES), which includes factors such as income, educational attainment, occupational prestige, and access to resources, is a key determinant of obesity. In this scoping mini-review, we summarized review articles and meta-analyses of the SES-obesity association. From the 1980s to the present, cross-sectional studies have demonstrated a persistent socioeconomic gradient in obesity in which the association is negative in developed countries and positive in developing countries. Longitudinal studies have revealed the bidirectionality of the SES-obesity association; some studies demonstrate that socioeconomic adversity precedes the onset of obesity, while others provide evidence of reverse causality. While earlier studies relied on anthropometric assessments of weight and height to define obesity, the use of modern technologies like dual-energy x-ray absorptiometry and bioelectrical impedance have demonstrated that the socioeconomic gradient in obesity is robust across multiple indicators of body composition, including direct measures of lean and fat mass. More recently, examination of mediators and moderators of the SES-obesity association have highlighted causal pathways and potential intervention targets, with a focus on health behaviors, environmental conditions, psychological factors, and biological processes. We describe current gaps in knowledge and propose opportunities for future innovation to reduce the burden of obesity and related socioeconomic disparities.

The implications of self-reported body weight and height for measurement error in BMI

We designed an experiment to explore the extent of measurement error in body mass index (BMI), when based on self-reported body weight and height. We find that there is a systematic age gradient in the reporting error in BMI, while there is limited evidence of systematic associations with gender, education and income. This is reassuring evidence for the use of self-reported BMI in studies that use it as an outcome, for example, to analyse socioeconomic gradients in obesity. However, our results suggest a complex structure of non-classical measurement error in BMI, depending on both individuals’ and within-household peers’ true BMI. This may bias studies that use BMI based on self-reported data as a regressor. We also observe non-classical reporting error in height and weight — taller people seem to report their height more accurately, while a nonlinear relationship is evident for weight, with a sharper increase in reporting errors for those of greater weight. Common methods to mitigate reporting error in BMI using predictions from corrective equations do not fully eliminate reporting heterogeneity associated with individual and within-household true BMI. Overall, the presence of non-classical error in BMI highlights the importance of collecting measured body weight and height data in large social science datasets.

Obesity and food away from home: What drives the socioeconomic gradient in excess body weight?

Rising obesity rates are one of the most challenging public health issues in many emerging economies. To what extent food away from home (FAFH) and its nutritional components are behind this rise is not yet well understood. To address the issue, this paper combines a representative restaurant survey that includes detailed information on the diet quality of the most widely consumed meals and their nutritional components from 1605 restaurants and a representative household survey with anthropometric measures of adult women living in 40 neighborhoods in the Lima Metropolitan Area. One important advantage of the dataset is the fact that nutrition professionals observed the preparation of the meals and that they were subject to a detailed laboratory analysis. Exploiting this data, we examine the differences in nutritional quality of FAFH among 40 neighborhoods of various socioeconomic groups and explore whether these differences can explain part of the observed socioeconomic gradient in excess body weight. The findings indicate that less healthy food in restaurants located in the food environment of the households is significantly associated with higher rates of obesity and overweight. In particular, the high supply and intake of sodium potentially drives higher excess body weight. The study also finds that up to 15 percent of the socioeconomic gradient in obesity is attributable to the restaurant food quality in the food environment of the households.

Teachers’ perspectives on the barriers to healthy lifestyle behaviors among adolescent girls of disadvantaged backgrounds in Ireland: A qualitative study

Though adolescence is a particularly sensitive period regarding the development of long-lasting health-related attitudes and behaviors, little research has examined the factors which influence their engagement in such behaviors. Adolescent females are particularly sensitive to suffer from overweight and obesity. It is also a time that can impact the health patterns of future generations due to the influence of preconception maternal factors on the health of their offspring. Furthermore, much research has identified a strong socioeconomic gradient in obesity in Ireland, with individuals from low socioeconomic backgrounds being particularly likely to develop unhealthy habits. The current study aimed to develop an understanding of the factors which influence the health-related behaviors of adolescent girls of low-socioeconomic status in Ireland, an underrepresented yet particularly sensitive cohort. Semi-structured interviews were conducted with nine teachers from disadvantaged schools in Dublin and were examined using a thematic analytic approach. Nine themes were identified: lack of interest and knowledge, lack of self-confidence, the dual role of modern technology, behaviors of significant others, need for good role models, availability of convenience foods, inadequate existing approaches and initiatives, lack of resources to promote a healthy lifestyle, and living difficulties at home and in the community. Findings suggested ways for intervening at personal, interpersonal, organizational and community levels. In conclusion, a range of practical changes are required in the home, school, and community environments in order to improve the health of these individuals, and ultimately to improve the health of future generations.

The Implications of Self-Reported Body Weight and Height for Measurement Error in BMI

We designed an experiment to explore the extent of measurement error in body mass index (BMI), when based on self-reported body weight and height. We find that there is a systematic age gradient in the reporting error in BMI, while there is limited evidence of systematic associations with gender, education and income. This is reassuring evidence for the use of self-reported BMI in studies that use it as an outcome, for example, to analyse socioeconomic gradients in obesity. However, our results suggest a complex structure of non-classical measurement error in BMI, depending on both individuals' and within-household peers' true BMI. This may bias studies that use BMI based on self-reported data as a regressor. Common methods to mitigate reporting error in BMI using predictions from corrective equations do not fully eliminate reporting heterogeneity associated with individual and within-household true BMI. Overall, the presence of non-classical error in BMI highlights the importance of collecting measured body weight and height data in large social science datasets.

Personal relative deprivation increases self-selected portion sizes and food intake

Cues and experiences of the deprivation of financial/material resources have been associated with increased caloric intake and risk for overweight/obesity. Given that social comparisons may serve as a powerful reference for the adequacy of one's standing and resources, the present research tested whether subjective feelings of personal relative deprivation (PRD) or “losing out” to others stimulates calorie selection and intake. Study 1 demonstrated that self-reported chronic experiences of PRD positively predicted calories selected for a portion and consumed during an ad-libitum meal. Study 2 revealed that experimentally-induced PRD resulted in an increase in the amount of calories selected on a portion selection task and a stronger desire to consume the foods. Consequently, these findings demonstrate that chronic and acute subjective deprivation of non-food resources may contribute to socioeconomic gradients in obesity, and that perceived social inequality may have inherently obesogenic properties that promote excess calorie intake.

Mere experience of low subjective socioeconomic status stimulates appetite and food intake

Among social animals, subordinate status or low social rank is associated with increased caloric intake and weight gain. This may reflect an adaptive behavioral pattern that promotes acquisition of caloric resources to compensate for low social resources that may otherwise serve as a buffer against environmental demands. Similarly, diet-related health risks like obesity and diabetes are disproportionately more prevalent among people of low socioeconomic resources. Whereas this relationship may be associated with reduced financial and material resources to support healthier lifestyles, it remains unclear whether the subjective experience of low socioeconomic status may alone be sufficient to stimulate consumption of greater calories. Here we show that the mere feeling of lower socioeconomic status relative to others stimulates appetite and food intake. Across four studies, we found that participants who were experimentally induced to feel low (vs. high or neutral) socioeconomic status subsequently exhibited greater automatic preferences for high-calorie foods (e.g., pizza, hamburgers), as well as intake of greater calories from snack and meal contexts. Moreover, these results were observed even in the absence of differences in access to financial resources. Our results demonstrate that among humans, the experience of low social class may contribute to preferences and behaviors that risk excess energy intake. These findings suggest that psychological and physiological systems regulating appetite may also be sensitive to subjective feelings of deprivation for critical nonfood resources (e.g., social standing). Importantly, efforts to mitigate the socioeconomic gradient in obesity may also need to address the psychological experience of low social status.

Obesity continues to increase in the majority of the population in mid-Sweden-a 12-year follow-up.

The aim was to investigate trends in the prevalence of obesity by age and level of education in the general population in mid-Sweden from year 2000 to 2012. A postal questionnaire was sent to a random population sample aged 25-74 years in years 2000, 2004, 2008 and 2012. The overall response rates were 67%, 65%, 60% and 53%, respectively, and the study included 29 017, 27 385, 25 910 and 24 152 respondents, respectively. Obesity (BMI ≥ 30 kg/m(2)) was based on self-reported weight and height. The age-standardized prevalence of obesity increased from 13% to 17% in women and from 12% to 17% in men between 2000 and 2012. Obesity increased in all age groups from 2000 to 2008 and continued to increase among the middle aged (45-64 years) between 2008 and 2012. The socioeconomic gradient in obesity changed during the study period since the absolute increase in obesity was steepest at the middle educational level. In 2012, the prevalence of obesity was almost twice as high at both middle and low educational levels compared with high educational level. The 'true' prevalence of adult obesity, corrected for self-reported weight and height, was around 20% in 2012 for both men and women. In the majority, among the middle-aged and those with secondary education, the prevalence of obesity continued to increase even between 2008 and 2012.

Validity of silhouette showcards as a measure of body size and obesity in a population in the African region: A practical research tool for general-purpose surveys.

BackgroundThe purpose of this study is to validate the Pulvers silhouette showcard as a measure of weight status in a population in the African region. This tool is particularly beneficial when scarce resources do not allow for direct anthropometric measurements due to limited survey time or lack of measurement technology in face-to-face general-purpose surveys or in mailed, online, or mobile device-based surveys.MethodsA cross-sectional study was conducted in the Republic of Seychelles with a sample of 1240 adults. We compared self-reported body sizes measured by Pulvers’ silhouette showcards to four measurements of body size and adiposity: body mass index (BMI), body fat percent measured, waist circumference, and waist to height ratio. The accuracy of silhouettes as an obesity indicator was examined using sex-specific receiver operator curve (ROC) analysis and the reliability of this tool to detect socioeconomic gradients in obesity was compared to BMI-based measurements.ResultsOur study supports silhouette body size showcards as a valid and reliable survey tool to measure self-reported body size and adiposity in an African population. The mean correlation coefficients of self-reported silhouettes with measured BMI were 0.80 in men and 0.81 in women (P < 0.001). The silhouette showcards also showed high accuracy for detecting obesity as per a BMI ≥ 30 (Area under curve, AUC: 0.91/0.89, SE: 0.01), which was comparable to other measured adiposity indicators: fat percent (AUC: 0.94/0.94, SE: 0.01), waist circumference (AUC: 0.95/0.94, SE: 0.01), and waist to height ratio (AUC: 0.95/0.94, SE: 0.01) amongst men and women, respectively. The use of silhouettes in detecting obesity differences among different socioeconomic groups resulted in similar magnitude, direction, and significance of association between obesity and socioeconomic status as when using measured BMI.ConclusionsThis study highlights the validity and reliability of silhouettes as a survey tool for measuring obesity in a population in the African region. The ease of use and cost-effectiveness of this tool makes it an attractive alternative to measured BMI in the design of non-face-to-face online- or mobile device-based surveys as well as in-person general-purpose surveys of obesity in social sciences, where limited resources do not allow for direct anthropometric measurements.

Cross-national comparison of socioeconomic inequalities in obesity in the United States and Canada.

IntroductionPrior cross-national studies of socioeconomic inequalities in obesity have only compared summary indices of inequality but not specific, policy-relevant dimensions of inequality: (a) shape of the socioeconomic gradient in obesity, (b) magnitude of differentials in obesity across socioeconomic levels and, (c) level of obesity at any given socioeconomic level. We use unique data on two highly comparable societies – U.S. and Canada - to contrast each of these inequality dimensions.MethodsData came from the 2002/2003 Joint Canada/U.S. Survey of Health. We calculated adjusted prevalence ratios (APRs) for obesity (compared to normal weight) by income quintile and education group separately for both nations and, between Canadians and Americans in the same income or education group.ResultsIn the U.S., every socioeconomic group except the college educated had significant excess prevalence of obesity. By contrast in Canada, only those with less than high school were worse off, suggesting that the shape of the socioeconomic gradient differs in the two countries. U.S. differentials between socioeconomic levels were also larger than in Canada (e.g., PR quintile 1 compared to quintile 5 was 1.82 in the U.S. [95 % CI: 1.52-2.19] but 1.45 in Canada [95 % CI: 1.10-1.91]). At the lower end of the socioeconomic gradient, obesity was more prevalent in the U.S. than in Canada.ConclusionsOur results suggest there is variation between U.S. and Canada in different dimensions of socioeconomic inequalities in obesity. Future research should examine a broader set of nations and test whether specific policies or environmental exposures can explain these differences.

Development of socioeconomic inequalities in obesity among Dutch pre-school and school-aged children.

To investigate the emergence of the inverse socioeconomic gradient in body mass index (BMI) in the first 6 years of life. Furthermore, associations of socioeconomic position (SEP) with BMI and total fat mass (%) were assessed at age 6, and potential mediating factors in the pathway between SEP and children's body composition were investigated. Nearly 3,656 Dutch children participating in a prospective cohort study in Rotterdam, the Netherlands, were included from 2002 to 2006. Maternal educational level and net household income were used as indicators of SEP. BMI and fat mass were both outcome measures. Associations and mediation analyses were investigated using linear mixed models and linear regression analyses. The lowest SEP groups showed a larger increase in BMI over time as compared to the highest SEP groups (P < 0.001), which resulted in the emergence of the inverse SEP gradient around 3-4.5 years of age. In 6-year-old children, both BMI and total fat mass were significantly higher for children of low educated mothers (difference in BMI SDS: 0.24; 95% CI 0.15, 0.33; and in total fat mass (%): 2.68; 95% CI 2.19, 3.17), which was also shown for children with a low household income. This was mainly explained by parental BMI and prenatal smoking. The inverse socioeconomic gradient in obesity emerges during the preschool period, and widens with increasing age. A public health strategy aimed at tackling the development of inequalities in obesity in early childhood needs to start before birth and should include the prevention of prenatal smoking and obesity of parents.

Current mapping of obesity.

Obesity is a major risk factor for non-communicable diseases (NCDs), such as diabetes, cardiovascular diseases, and cancers. The worldwide prevalence of obesity has almost doubled between 1980 and 2008. In some regions, such as Europe, the Eastern Mediterranean and the Americas, more than 50% of women are overweight. Tonga, Nauru and the Cook Islands show the highest prevalence of obesity worldwide, above 60% in men and in women. China and the United States are the countries that experienced the largest absolute increase in the number of overweight and obese people between 1980 and 2008, followed by Brazil and Mexico. The regions with the largest increase in the prevalence of female obesity were Central Latin America, Oceania and Southern Latin America. Updated data provide evidence that the progression of the epidemic has effectively slowed for the past ten years in several countries. In low-income countries obesity is generally more prevalent among the better-off, while disadvantaged groups are increasingly affected as countries grow. Many studies have shown an overall socio-economic gradient in obesity in modern industrialized societies. Rates tend to decrease progressively with increasing socio-economic status. Children obesity rates in Spain are amongst the highest in the OECD. One in 3 children aged 13 to 14 are overweight. Overweight in infants and young children is observed in the upper middle-income countries. However, the fastest growth occurs in the group of lower middle-income countries. There is a growing body of evidence for an inverse association between SES and child obesity in developed countries. The prevalence of overweight and obesity is high in all age groups in many countries, but especially worrying in children and adolescents in developed countries and economies in transition.

Twenty-five year trends in body mass index by education and income in Finland

BackgroundThe socioeconomic gradient in obesity and overweight is amply documented. However, the contribution of different socioeconomic indicators on trends of body mass index (BMI) over time is less well known. The aim of this study was to investigate the associations of education and income with (BMI) from the late 1970s to the early 2000s.MethodsData were derived from nationwide cross-sectional health behaviour surveys carried out among Finns annually since 1978. This study comprises data from a 25-year period (1978–2002) that included 25 339 men and 25 330 women aged 25–64 years. BMI was based on self-reported weight and height. Education in years was obtained from the questionnaire and household income from the national tax register. In order to improve the comparability of the socioeconomic position measures, education and income were divided into gender-specific tertiles separately for each study year. Linear regression analysis was applied.ResultsAn increase in BMI was observed among men and women in all educational and income groups. In women, education and income were inversely associated with BMI. The magnitudes of the associations fluctuated but stayed statistically significant over time. Among the Finnish men, socioeconomic differences were more complicated. Educational differences were weaker than among the women and income differences varied according to educational level. At the turn of the century, the high income men in the lowest educational group had the highest BMI whereas the income pattern in the highest educational group was the opposite.ConclusionNo overall change in the socio-economic differences of BMI was observed in Finland between 1978 and 2002. However, the trends of BMI diverged in sub-groups of the studied population: the most prominent increase in BMI took place in high income men with low education and in low income men with high education. The results encourage further research on the pathways between income, education, living conditions and the increasing BMI.

Dramatic Increases in Obesity and Overweight Prevalence and Body Mass Index Among Ethnic-Immigrant and Social Class Groups in the United States, 1976–2008

This study examined trends in US obesity and overweight prevalence and body mass index (BMI) among 30 immigrant groups, stratified by race/ethnicity and length of immigration, and among detailed education, occupation, and income/poverty groups from 1976 to 2008. Using 1976–2008 National Health Interview Surveys, differentials in obesity, overweight, and BMI, based on self-reported height and weight, were analyzed by using disparity indices, logistic, and linear regression. The obesity prevalence for the US population aged ≥18 tripled from 8.7% in 1976 to 27.4% in 2008. Overweight prevalence increased from 36.9% in 1976 to 62.0% in 2008. During 1991–2008, obesity prevalence for US-born adults increased from 13.9 to 28.7%, while prevalence for immigrants increased from 9.5 to 20.7%. While immigrants in each ethnic group and time period had lower obesity and overweight prevalence and BMI than the US-born, immigrants’ risk of obesity and overweight increased with increasing duration of residence. In 2003–2008, obesity prevalence ranged from 2.3% for recent Chinese immigrants to 31–39% for American Indians, US-born blacks, Mexicans, and Puerto Ricans, and long-term Mexican and Puerto Rican immigrants. Between 1976 and 2008, the obesity prevalence more than quadrupled for those with a college education or sales occupation. Although higher prevalence was observed for lower education, income, and occupation levels in each period, socioeconomic gradients in obesity and overweight decreased over time because of more rapid increases in prevalence among higher socioeconomic groups. Continued immigrant and socioeconomic disparities in prevalence will likely have substantial impacts on future obesity trends in the US.

Trends in social inequalities in obesity: Belgium, 1997 to 2004

Objectives Studies examining the time trend in social inequalities in obesity have yielded diverse results. The aim of this study is to investigate whether social inequalities in obesity have increased overtime in Belgium. Methods We used data from three national cross-sectional health interview surveys (1997 n = 7953, 2001 n = 8887, and 2004 n = 9709) to estimate age-standardized obesity prevalence and a series of summary measures reflecting health inequalities in men and women aged 18 years and older. Results For males, a clear socioeconomic gradient was observed between obesity and education. This gradient witnessed a large increase between the years 1997 and 2004. For instance, the relative index of inequality increased from 1.92 (95% CI: 1.16–3.18) to 3.71 (95% CI: 2.49–5.54). Social inequalities in female obesity indicate a different pattern. Our results revealed a very steep socioeconomic gradient for female obesity, but overtime, no significant change was observed. The relative index of inequality for female obesity was 4.04 (95% CI: 2.47–6.63) in 1997 and 4.03 (95% CI: 2.75–5.90) in 2004. Conclusions Using three comparable nation-wide population-based surveys, our study has shown that in Belgium from 1997 to 2004, the socioeconomic gradient in obesity has increased for males and persisted for females.

Socioeconomic gradient in body size and obesity among women: the role of dietary restraint, disinhibition and hunger in the Whitehall II study.

To examine the associations between three psychological eating behaviour variables--restraint, hunger and disinhibition--and body weight and size, and to assess their explanatory power for the employment grade gradients in body measurement. Cross-sectional analysis of self-report and clinical data. : In all, 1470 women (aged 45-68 y, mean 56.3, s.d. 6.0 y), body mass index (BMI) 26.3 (4.8) kg/m(2) at phase 5 (1997-98) of the Whitehall II study. Employment grade was measured in six bands ranging from clerical (lowest) to administrative (highest). Five measures of body size were examined: BMI, weight in kilograms, waist and hip measurement in centimetres and waist-hip ratio. The eating behaviour variables were measured using Stunkard and Messick's (1985) Three-Factor Eating Questionnaire (TFEQ). Disinhibition and hunger scores were strongly and directly associated with all measures of body weight and size. Restraint score was not directly associated with body size and weight. An interaction between restraint and disinhibition scores was found. The low-restraint-high-disinhibition group (based on median score splits) were the heaviest (BMI 28.5 kg/m(2)) and largest (waist 85.8 cm), while the low-restraint-low-disinhibition group were the lightest (BMI 24.2 kg/m(2)) and smallest (waist 76.3 cm). Employment grade gradients in body weight and size remained largely unchanged after adjustment for dietary restraint. Moderate attenuations were found for disinhibition scores (3.6-15.0%) and hunger (4.8-19.9%) on the five body-size measures. Among middle-aged women high scores on hunger and disinhibition, as measured by the TFEQ, are associated with greater body size. Restraint relates to body size through its interaction with disinhibition. Individuals with high disinhibition and any level of restraint are heavier and larger than those with low levels of disinhibition. High disinhibition coupled with low levels of restraint is associated with the greatest weight and size. Hunger and disinhibition explain a moderate amount of the gradient in body size across employment grade and may be useful concepts for future work on the socio-economic gradient in obesity and overweight.

Psychosocial aspects of obesity: Individual and societal perspectives

This review article describes psychosocial causes and consequences of obesity in societies and at the individual level, highlighting aspects of the problem that are frequently overlooked in nutritional and medical research. The socio-economic gradient in obesity in modern society is well-documented, while the origins of this gradient are difficult to explain. Specifically, it is currently not well understood which aspects of the less advantaged socio-economic environment cause obesity. There is, however, strong evidence that the condition of obesity creates a situation of downward social mobility, possibly resulting in a positive feedback cycle. Regarding obesity's psychological origins and consequences, similar conclusions have been drawn: psychological characteristics associated with the obese state are more likely to be consequences than causes, again as a result of the negative attitudes of society towards obesity. In this context, it is interesting to note that perceptions of ideal body shape have become leaner in recent decades (particularly in women), at the same time that the prevalence of obesity is increasing. The fact that dietary and physical characteristics of the modem macroenvironment are making it increasingly difficult to avoid becoming overweight, despite the high societal value placed on being underweight, represents an intriguing contradiction of modern times.