title: Time trends and sex differences in associations between socioeconomic status indicators and overweight-obesity in Mexico (2006-2012).
abstract: BACKGROUND
  Although the associations between specific socioeconomic status (SES) indicators and overweight or obesity (OWOB) have been studied in different countries, fewer evidence exists for these associations when multiple SES indicators are considered simultaneously. Furthermore, there are few studies investigating time trends in OWOB and their relation with SES in upper-middle income countries, especially for men. The present study contributes to a better understanding of the nature and evolution of the associations between SES indicators and OWOB in the Mexican adult population.
  
  
  METHODS
  We pooled data from the 2006 and 2012 National Health and Nutrition Surveys in Mexico and obtained covariate-adjusted prevalence from a design-based logistic multiple regression model. Covariates included a wealth index, education, occupational status, marital status, and all interactions for each covariate with sex (male/female) and survey year.
  
  
  RESULTS
  For men, the association between wealth and OWOB remained positive in general but curvature was more evident in 2012. The wealth-OWOB association in women showed an inverted-U pattern at both years with a positive slope that turned into a negative one as wealth increased. Among women, OWOB prevalence at the college/university education level was approximately 12.0 ± 2.4 (percentage points ± standard error) lower compared with the elementary education level. We did not find differences between educational categories for men in 2006, but in 2012 OWOB tended to be higher among the more educated. The prevalence of obesity in women increased at wealth levels from the middle and upper-middle section of the wealth distributions. Overall OWOB prevalence was near 70 % in 2012 for both sexes.
  
  
  CONCLUSIONS
  Among Mexican women, the associations between SES indicators and excess body weight were consistent to those found in developed countries. Among Mexican men, higher education was not associated with a lower prevalence of OWOB but the positive association between wealth and OWOB weakened as wealth increased. The overall prevalence of OWOB was very high for both sexes; its reduction should remain a public health priority given the consequences of nutrition-related chronic diseases, disability and health care costs.
authors.affiliation: Nutrition and Health Research Center, Av. Universidad 655 Col. Sta. María, Av. Universidad 655 Col. Sta. María Ahuacatitlán, 62100, Cuernavaca, Morelos, Mexico. amado.quezada@insp.mx.
authors.forename: Amado D
authors.initials: AD
authors.lastname: Quezada
authors.affiliation: Nutrition and Health Research Center, Av. Universidad 655 Col. Sta. María, Av. Universidad 655 Col. Sta. María Ahuacatitlán, 62100, Cuernavaca, Morelos, Mexico. alozada@insp.mx.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Lozada-Tequeanes
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D019049:Developed Countries; D004522:Educational Status; D005260:Female; D059066:Gross Domestic Product / Q000639:trends; D006306:Health Surveys; D006801:Humans; D007182:Income / Q000706:statistics & numerical data*; D016015:Logistic Models; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology; D050177:Overweight / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012737:Sex Factors; D012959:Socioeconomic Factors; D013997:Time Factors; D055815:Young Adult