Educational inequalities in obesity: a multilevel analysis of survey data from cities in Latin America

The Association between Educational Attainment and the Risk of Nonalcoholic Fatty Liver Disease among Chinese Adults: Findings from the REACTION Study

Background/Aims

: Low educational attainment is a well-established risk factor for nonalcoholic fatty liver disease (NAFLD) in developed areas. However, the association between educational attainment and the risk of NAFLD is less clear in China.

Methods

: A cross-sectional study including over 200,000 Chinese adults across mainland China was conducted. Information on education level and lifestyle factors were obtained through standard questionnaires, while NAFLD and advanced fibrosis were diagnosed using validated formulas. Outcomes included the risk of NAFLD in the general population and high probability of fibrosis among patients with NAFLD. Logistic regression analysis was employed to estimate the risk of NAFLD and fibrosis across education levels. A causal mediation model was used to explore the potential mediators.

Results

: Comparing with those receiving primary school education, the multi-adjusted odds ratios (95% confidence intervals) for NAFLD were 1.28 (1.16 to 1.41) for men and 0.94 (0.89 to 0.99) for women with college education after accounting for body mass index. When considering waist circumference, the odds ratios (95% CIs) were 0.94 (0.86 to 1.04) for men and 0.88 (0.80 to 0.97) for women, respectively. The proportions mediated by general and central obesity were 51.00% and 68.04% for men, while for women the proportions were 48.58% and 32.58%, respectively. Furthermore, NAFLD patients with lower educational attainment showed an incremental increased risk of advanced fibrosis in both genders.

Conclusions

: In China, a low education level was associated with a higher risk of prevalent NAFLD in women, as well as high probability of fibrosis in both genders.

Socioeconomic Position, Pre-Obesity and Obesity in Latin American Cities: A Systematic Review

Currently the socioeconomic gradient of obesity it is not well understood in the urban population in Latin American. This study reviewed the literature assessing associations between pre-obesity, obesity, and socioeconomic position (SEP) in adults living in urban areas in Latin American countries. PubMed and SciELO databases were used. Data extraction was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We extracted data on the association between SEP (e.g., education, income), pre-obesity (body mass index [BMI] ≥ 25 and < 30 kg/m2) and obesity (BMI ≥ 30 kg/m2). Relative differences between low and high SEP groups were assessed and defined a priori as significant at p < 0.05. Thirty-one studies met our inclusion criteria and most were conducted in Brazil and Mexico (22 and 3 studies, respectively). One study presented nonsignificant associations. Forty-seven percent of associations between education or income and pre-obesity were negative. Regarding obesity, 80 percent were negative and 20 percent positive. Most negative associations were found in women while in men they varied depending on the indicator used. Pre-obesity and obesity by SEP did not follow the same pattern, revealing a reversal of the obesity social gradient by SEP, especially for women in Latin America, highlighting the need for articulated policies that target structural and agentic interventions.

Determinants of obesity in Latin America

Obesity rates are increasing almost everywhere in the world, although the pace and timing for this increase differ when populations from developed and developing countries are compared. The sharp and more recent increase in obesity rates in many Latin American countries is an example of that and results from regional characteristics that emerge from interactions between multiple factors. Aware of the complexity of enumerating these factors, we highlight eight main determinants (the physical environment, food exposure, economic and political interest, social inequity, limited access to scientific knowledge, culture, contextual behaviour and genetics) and discuss how they impact obesity rates in Latin American countries. We propose that initiatives aimed at understanding obesity and hampering obesity growth in Latin America should involve multidisciplinary, global approaches that consider these determinants to build more effective public policy and strategies, accounting for regional differences and disease complexity at the individual and systemic levels.

Early life predictors of body composition trajectories from adolescence to mid-adulthood

OBJECTIVES

Guatemala has experienced rapid increases in adult obesity. We characterized body composition trajectories from adolescence to mid-adulthood and determined the predictive role of parental characteristics, early life factors, and a nutrition intervention.

METHODS

One thousand three hundred and sixty-four individuals who participated as children in a nutrition trial (1969-1977) were followed prospectively. Body composition characterized as body mass index (BMI), fat mass index (FMI), and fat-free mass indices (FFMI), was available at four ages between 10 and 55 years. We applied latent class growth analysis to derive sex-specific body composition trajectories. We estimated associations between parental (age, height, schooling) and self-characteristics (birth order, socioeconomic status, schooling, and exposure to a nutrition supplement) with body composition trajectories.

RESULTS

In women, we identified two latent classes of FMI (low: 79.6%; high: 20.4%) and BMI (low: 73.0%; high: 27.0%), and three of FFMI (low: 20.2%; middle: 55.9%; high: 23.9%). In men, we identified two latent classes of FMI (low: 79.6%; high: 20.4%) and FFMI (low: 62.4%; high: 37.6%), and three of BMI (low: 43.1%; middle: 46.9%; high: 10.0%). Among women, self's schooling attainment inversely predicted FMI (OR [being in a high latent class]: 0.91, 95% CI: 0.85, 0.97), and maternal schooling positively predicted FFMI (OR: 1.16, 95% CI: 0.97, 1.39). Among men, maternal schooling, paternal age, and self's schooling attainment positively predicted FMI. Maternal schooling positively predicted FFMI, whereas maternal age and paternal schooling were inverse predictors. The nutrition intervention did not predict body composition class membership.

CONCLUSIONS

Parents' age and schooling, and self's schooling attainment are small but significant predictors of adult body composition trajectories.

Gender differences in the association of individual and contextual socioeconomic status with hypertension in 230 Latin American cities from the SALURBAL study: a multilevel analysis

BACKGROUND

Despite global interest in gender disparities and social determinants of hypertension, research in urban areas and regions with a high prevalence of hypertension, such as Latin America, is very limited. The objective of this study was to examine associations of individual- and area-level socioeconomic status with hypertension in adults living in 230 cities in eight Latin America countries.

METHODS

In this cross-sectional study, we used harmonized data from 109,184 adults (aged 18-97 years) from the SALURBAL (Salud Urbana en America Latina/Urban Health in Latin America) project. Hypertension was assessed by self-report. Individual-, sub-city- and city-level education were used as proxies of socioeconomic status. All models were stratified by gender.

RESULTS

Higher individual-level education was associated with lower odds of hypertension among women (university education or higher versus lower than primary: odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.61-0.74) but higher odds among men (OR = 1.65; 95%CI 1.47-1.86), although in men an inverse association emerged when measured blood pressure was used (OR = 0.86; 95%CI 0.76-0.97). For both genders, living in sub-city areas with higher educational achievement was associated with higher odds of hypertension (OR per standard deviation [SD] = 1.07, 95%CI = 1.02-1.12; OR = 1.11 per SD, 95%CI = 1.05-1.18, for women and men, respectively). The association of city-level education with hypertension varied across countries. In Peru, there was an inverse association (higher city level education was associated with lower odds of hypertension) in women and men, but in other countries no association was observed. In addition, the inverse association of individual-level education with hypertension became stronger (in women) or emerged (in men) as city or sub-city education increased.

CONCLUSION

The social patterning of hypertension differs by gender and by the level of analysis highlighting the importance of context- and gender-sensitive approaches and policies to reduce the prevalence of hypertension in Latin America.

Efficacy of front-of-pack warning label system versus guideline for daily amount on healthfulness perception, purchase intention and objective understanding of nutrient content of food products in Guatemala: a cross-over cluster randomized controlled experiment

BACKGROUND

Front-of-package warning labels (FOPWL) have been adopted in many countries aiming at reducing the consumption of unhealthy food and drink products and have also been considered in Guatemala. The aim of the study is to evaluate the efficacy of FOPWL versus Guidelines for Daily Amount (GDA) on products' healthfulness perception (HP), purchase intention (PI) and the objective understanding of the nutrient content (UNC) in Guatemala.

METHODS

Participants (children and adults) (n = 356) were randomly assigned to evaluate either FOPWL or GDA during a crossover cluster randomized experiment in rural and urban areas across 3 phases of exposure. During phase 1, participants evaluated mock-up images of single products (single task) and compared pairs of products within the same food category (comparison task) without any label. In phase 2, participants evaluated labels only (without any product), and during phase 3, they evaluated the same products and questions from phase 1, now depicting the assigned front-of-package label. We generated indicators for single-task questions and scores for comparison tasks, one for each HP, PI and UNC questions. We used intention-to-treat, difference-in-difference regression analysis to test whether exposure to FOPWL was associated with HP, PI and UNC, compared to GDA. We also tested models for children and adults and by area (rural/urban) separately adjusting for sociodemographic variables.

RESULTS

In single tasks, FOPWL significantly decreased the PI (β -18.1, 95%CI -23.3, -12.8; p < 0.001) and the HP (β -13.2, 95%CI -18.4, -7.9; p < 0.001) of unhealthy food products compared to GDA. In the comparison task, FOPWL significantly increased the UNC (β 20.4, 95%CI 17.0, 23.9; p < 0.001), improved PI towards healthier choices (OR 4.5, 95%CI 2.9, 7.0 p < 0.001) and HP (OR 5.6, 95%CI 2.8, 11.1; p < 0.001) compared to GDA. Similar results were found in children and adults and in urban and rural settings.

CONCLUSIONS

FOPWL reduces products' healthfulness perception and purchase intention, and increases understanding of products' nutrient content compared to GDA.

School environments and obesity: a systematic review of interventions and policies among school-age students in Latin America and the Caribbean

BACKGROUND

The rapid rise in obesity rates among school children in Latin America and the Caribbean (LAC) could have a direct impact on the region's physical and mental health, disability, and mortality. This review presents the available interventions likely to reduce, mitigate and/or prevent obesity among school children in LAC by modifying the food and built environments within and around schools.

METHODS

Two independent reviewers searched five databases: MEDLINE, Web of Science, Cochrane Library, Scopus and Latin American and Caribbean Health Sciences Literature for peer-reviewed literature published from 1 January 2000 to September 2021; searching and screening prospective studies published in English, Spanish and Portuguese. This was followed by data extraction and quality assessment using the Cochrane risk-of-bias tool (RoB 2) and the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I), adopting also the PRISMA 2020 guidelines. Due to the heterogeneity of the intervention's characteristics and obesity-related measurements across studies, a narrative synthesis was conducted.

RESULTS

A total of 1342 research papers were screened, and 9 studies were included; 4 in Mexico, and 1 each in Argentina, Brazil, Chile, Colombia, and Ecuador. Four studies reported strategies for modifying food provision; four other targeted the built environment, (modifying school premises and providing materials for physical activity); a final study included both food and built environment intervention components. Overall, two studies reported that the intervention was significantly associated with a lower increase over time in BMI/obesity in the intervention against the control group. The remaining studies were non-significant.

CONCLUSIONS

Data suggest that school environmental interventions, complementing nutritional and physical education can contribute to reduce incremental childhood obesity trends. However, evidence of the extent to which food and built environment components factor into obesogenic environments, within and around school grounds is inconclusive. Insufficient data hindered any urban/rural comparisons. Further school environmental intervention studies to inform policies for preventing/reducing childhood obesity in LAC are needed.

Are Women's Empowerment and Income Inequality Associated with Excess Weight in Latin American Cities?

While income gradients and gender inequalities in excess weight have been noted elsewhere, data from Latin American cities is lacking. We analyzed gender-specific associations between city-level women's empowerment and income inequality with individual-level overweight/obesity, assessing how these associations vary by individual education or living conditions within cities in Latin America. Data came from national surveys and censuses, and was compiled by the SALURBAL project (Urban Health in Latin America). The sample included 79,422 individuals (58.0% women), living in 538 sub-cities, 187 cities, and 8 countries. We used gender-stratified Poisson multilevel models to estimate the Prevalence Rate Ratios (PRR) for overweight/obesity (body mass index ≥ 25 kg/m²) per a unit change in city-level women's empowerment (proxied by a score that measures gender inequalities in employment and education) and income inequality (proxied by income-based Gini coefficient). We also tested whether individual education or sub-city living conditions modified such associations. Higher city labor women's empowerment (in women) and higher city Gini coefficient (in men) were associated with a lower prevalence of overweight/obesity (PRR = 0.97 (95%CI 0.94, 0.99) and PRR = 0.94 (95%CI 0.90, 0.97), respectively). The associations varied by individual education and sub-city living conditions. For labor women's empowerment, we observed weakened associations towards the null effect in women with lower education and in residents of sub-cities with worse living conditions (men and women). For the Gini coefficient, the association was stronger among men with primary education, and a negative association was observed in women with primary education. Our findings highlight the need for promoting equity-based policies and interventions to tackle the high prevalence of excess weight in Latin American cities.

Greenhouse Gas Emissions Associated With the Mexican Diet: Identifying Social Groups With the Largest Carbon Footprint

Background

Most studies of the climate footprint of diets have been conducted in countries in the global north, but the majority of the world population lives in global south countries. We estimated total dietary greenhouse gas emissions (GHGE) in Mexico, examined the contribution of major food and beverage groups, and assessed variation across social groups.

Methods

We linked individual-level dietary data from the Mexican National Health and Nutrition Survey 2018 to the SHARP Indicators Database, containing GHGE estimates for 182 primary food and beverages.

Results

Mean dietary GHGE was 3.9 kg of carbon dioxide equivalent per person per day. Dietary GHGE is highest among those in young adulthood and middle age versus adolescents and older adults, and among males, those with higher educational attainment, higher socioeconomic status, that do not speak an indigenous language, and that live in urban areas.

Conclusion

The Mexican diet has a much lower carbon footprint than diets in other Latin American countries for which such estimates are available. In contrast to patterns observed in Argentina and Brazil, dietary GHGE was lowest in those in lower socioeconomic and educational strata and in rural areas. A better understanding of the differences in diet sustainability between and within countries will be needed for developing global and local strategies that meet the environmental sustainability goals.

Assessing comparative asset-based measures of material wealth as predictors of physical growth and mortality

Social scientists and policymakers have increasingly relied on asset-based indices of household wealth to assess social disparities and to identify economically vulnerable populations in low- and middle-income countries. In the last decade, researchers have proposed a number of asset-based measures that permit global comparisons of household wealth across populations in different countries and over time. Each of these measures relies on different assumptions and indicators, and little is known about the relative performance of these measures in assessing disparities. In this study, we assess four comparative, asset-based measures of wealth—the Absolute Wealth Estimate (AWE), the International Wealth Index (IWI), the Comparative Wealth Index (CWI), and the “Standard of Living” portion of the Multi-Dimensional Poverty Index (MPI), along with a variable measuring television ownership—and compare how well each predicts health related variables such as women's BMI, children's height-for-age Z scores, and infant mortality at the household and survey level. Analyzing data from over 300 Demographic and Health surveys in 84 countries (n = 2,304,928 households), we found that AWE, IWI, CWI, MPI are all highly correlated (r = 0.7 to 0.9). However, IWI which is based on a common set of universally weighted indicators, typically best accounts for variation in all three health measures. We discuss the implications of these findings for choosing and interpreting these measures of wealth for different purposes.

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Assessing four comparative, asset-based measures of wealth.

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The four comparative asset-based measures of wealth are all highly correlated.

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International Wealth Index best accounts for variation in adult female BMI, child height-for-age, and infant mortality.

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Asset-based measures of wealth relying on universal indicators and weights perform better at explaining variance.

Age at childbirth and change in BMI across the life-course: evidence from the INCAP Longitudinal Study

Background

Parity has been associated with both short- and long-term weight gain in women. However, it is not clear if timing of parity across the reproductive age has different associations with BMI.

Methods

To prospectively assess the association between age at childbirth and maternal change in BMI, we analyzed data from the ongoing INCAP Longitudinal Study, which started in 1969 in four villages in Guatemala. Cohort women (n=778) provided information on reproductive history and anthropometric measures were measured in 1988-89 (adolescence, 15 to 25y), 2002-04 (early adulthood, 26 to 36y) and 2015-17 (mid adulthood, 37 to 55y). We evaluated the associations of number of live births in the period preceding each study wave (1969-77 to 1988-89, 1988-89 to 2002-04 and 2002-04 to 2015-17) with BMI change in the same period using multivariable linear regression models.

Results

Number of live births between 1988 and 89 and 2002-04 was positively associated with increased BMI, while there was not an association between number of live births and BMI in the other intervals. Women who had one, two, or three or more children between 1988 and 89 and 2002-04 had 0.90 (kg/m², 95% CI: -0.55, 2.35), 2.39 (kg/m², 95% CI: 1.09, 3.70) and 2.54 (kg/m², 95% CI: 1.26, 3.82) higher BMI, respectively, than women who did not give birth in the same period.

Conclusions

Our findings suggest that women who had three or more children during early adulthood gained more weight compared to women who had no children in the same period. In contrast, women who had children earlier or later in their reproductive lives did not gain additional weight compared to those who did not have children during that period. Childbirth may have different associations with BMI based on the mother’s age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04485-6.

Nutritional and Socioeconomic Determinants of Overweight and Obesity in the French Amazon: The Health Barometer Study

OBJECTIVES

French Guiana is a multicultural overseas territory where obesity is a major public health problem. This study aimed to highlight the nutritional and socioeconomic determinants of overweight and obesity in different populations in French Guiana.

METHODS

A two-stage random sample of 1390 individuals aged 15 to 75 years was surveyed by telephone, and the participants were initially screened for diabetes. Logistic regression was fitted on the sample to adjust for potential confounding factors.

RESULTS

Overweight and obesity were found in 54.7% of the respondents, a higher proportion than in mainland France. There was a significant body image discrepancy in our population, with a higher risk of obesity among single women, often immigrants from the non-French Caribbean and South America, unemployed or low education.

CONCLUSIONS

The main factors associated with obesity were being a precariousness immigrant; there was often a mismatch between body image and overweight/obesity, which is a major obstacle to the improvement of dietary behaviors and lifestyle. This information provides operational clues as to where to act and the necessary adaptations to attempt to modify behaviors in a culturally-adapted manner.