Policy Brief: Weight Loss Success among Overweight and Obese Women of Mexican-origin Living In Mexico and the United States Sylvia Guendelman, Miranda Ritterman-Weintraub, Martha Kaufer-Horwitz (J Immigrant Minority Health [In Press]) Background Alarmingly high rates of overweight and obesity among adults of Mexican-origin living in the United States (US) and Mexico, place individuals at increased risk of diabetes, heart disease and other chronic illnesses. 1-3 In the US the prevalence of overweight and obesity stands at 78% among Mexican- American adults and in Mexico it is 71.3%. 4-x Despite high rates, especially among women, little is known about the factors associated with sustained weight loss at the population level. Most of what we know is limited to selected participants attending weight-loss programs or trials and involve only within country comparisons 5-6. Missing in this body of research is a cross-national perspective that compares US-born and Mexico-born populations living in the US with non-immigrants living in Mexico and considers the possible influences of sending and receiving countries on the probability of weight loss success. Developing an understanding of the contextual, social, cultural and behavioral factors associated with weight loss success is important for optimizing obesity prevention and intervention efforts Our study aimed to assess whether Mexican-origin women report more weight loss success over 12 months if they live in Mexico or the US. We defined weight loss success as losing at least 5% of body weight since even a 5 to 10% reduction in weight among overweight and obese individuals has been demonstrated to improve metabolic health and decrease cardiovascular disease and diabetes 7-8. We hypothesized that Mexican-origin women living in the US are more likely than women living in Mexico to lose a clinically significant amount of weight over one year. We additionally explored potential pathways by which differences in weight loss success might operate in each country, including the amount of screens and advise that women receive from their physicians, differences in educational attainment and lifestyle changes involved in weight loss success. The sample consisted of 5,061 women between 20 to 59 years old living in Mexico drawn from the 2006 Mexican National Health and Nutrition Survey (ENSANUT) 3 and 550 Mexican American women of similar age living in the US who had no known metabolic conditions. The Mexican American sample was drawn from the National Health and Nutrition Examination Survey (NHANES) 9 waves 2001-2008 and comprised immigrant women born in Mexico and US-born women of Mexican origin. The advantage of selecting these two surveys (and years) was the number of comparable fields on weight control, sociodemographic and health characteristics included in both questionnaires. Findings Weighted bivariate analyses indicated a different demographic and health profile for women in each country. Compared to Mexican American women living in the United States, women living in Mexico were older, had more births, were more likely to live with a partner and, had lower socio-economic 1
status. Women in Mexico also had on average a lower BMI and were less likely to have received a provider screen of overweight. Weight loss success among overweight and obese women was attained by 14% of women in Mexico and 18% of Mexican American women (Figure 1). A weighted multivariable logistic analysis showed that the crude odds of weight loss of 5 percent or more over one year was 31% higher (OR=1.31; 95%CI=1.01-1.70) among Mexican Americans than women in Mexico. Other logistic regression models examined the association of weight loss success with the sociodemographic and health variables for the two populations separately. Among women in Mexico, the odds of weight loss success was higher among those who had a high school degree or equivalent (OR=1.84; 95%CI=1.20-2.82) or at least some college (Or=2.31; 95%CI=1.31-4.09) compared with women who had some primary schooling; odds were also higher for women who received a provider screen of overweight (Or=2.12; 95%CI=1.48-3.07) and among women with a lower BMI. For each increase in BMI the odds decreased by O.06%. Among overweight and obese Mexican Americans, we found similar proportions of weight loss success among immigrants (18.9%) compared with US-born Mexican Americans (20.7%) (p=0.81). Overall among Mexican Americans no protective factors contributed to weight loss success in our adjusted models. Among Mexican immigrants, a lower education (OR=0.37; 95%CI=0.14-0.97) and an older age (OR=0.95; 95% CI=0.91-1.0) deterred weight loss success. We further analyzed weight loss strategies employed by a sub-group of women who lost at least 10 pounds-- a field available on both surveys. Compared to women in Mexico, a larger proportion of Mexican Americans reported eating less (52% vs. 87%) and eating less fat (2.5% vs. 44%), but the two populations did not differ with respect to employment of other strategies such as attending weight loss 2
programs, dieting, consuming fewer calories or engaging in exercise. Immigrants and US-born women did not differ with respect to any of these strategies, except that immigrants reportedly were somewhat less likely to exercise (p=0.06). Recommendations These findings serve as baseline evidence for future evaluations of public weight loss campaigns and of related countrywide policies that were implemented since the survey data were collected. Campaigns in Mexico and the US are mainly aimed at prevention of obesity and far less attention is given to successful weight loss management among apparently healthy women who are already overweight or obese. The results show that place matters for weight loss success among women with no known metabolic problems since contextual factors influence the chances of success. Identifying contextual factors can help design public health interventions for overweight and obese women in both countries. Mexican Americans living in the US had higher odds of weight loss success partly due to their successful use of weight loss strategies such as eating less and eating less fat. Future studies using a wider array of covariates need to identify other socio-demographic, lifestyle and behavioral factors that predict weight loss success among Mexican Americans. This is critical given evidence that shows that Mexican Americans are less likely than white non-latinos to sustain weight loss interventions and are twice as likely to regain lost weight 10. The findings also underscore the importance of tailoring interventions for overweight women in Mexico before they become obese since it appears to be easier to achieve weight loss success at an earlier stage of excessive weight gain. There is also a need to target women who are at risk of dropping out of high school and who are older since they are at higher risk of weight loss failure. The findings further demonstrate that only about 15% of overweight or obese women in Mexico who successfully lost weight reported having received a provider screen compared with 44% among their Mexican American counterparts. Much remains to be done in this area in both countries. Evidence shows that physicians who have knowledge, proficiency and self efficacy in overweight screen, advice and motivational techniques can help their patients change behaviors 11-12. Provider involvement in weight loss management may be an overlooked strategy to achieve population level weight reduction success, particularly in Mexico. A shared understanding of the similarities and unique issues faced by Mexican-origin women living in Mexico or the United States who are trying to lose weight can help us understand the importance of place and context in achieving weight loss success. Future studies need to explore the contextual effect of country of residence using more refined measures. 1. National Center for Health Statistics. Prevalence of overweight and obesity among adults: United States, 2003-2004. In NCHS Health E-Stats. April 2006 ; Edited by Centers for Disease Control and Prevention; 2006. 2. Flegal KM, Carroll MD, Ogden CL, Curtin LR. Prevalence and trends in obesity among US adults, 3
1999-2008. JAMA 2010; 303(3):235 241. 3. Olaiz-Fernández G, Rivera-Dommarco J, Shamah-Levy T, Rojas R, Villalpando-Hernández S, Hernández-Avila M, Sepúlveda-Amor J. Encuesta Nacional de Salud y Nutrición 2006. Cuernavaca, México: Instituto Nacional de Salud Pública, 2006. [http://www.insp.mx/images/stories/produccion/pdf/100722_cp3.pdf] 4. Gutiérrez JP, Rivera-Dommarco J, Shamah-Levy T, Villalpando-Hernández S, Franco A, Cuevas-Nasu L, Romero-Martínez M, Hernández-Ávila M. Encuesta Nacional de Salud y Nutrición 2012. Resultados Nacionales. Cuernavaca, México: Instituto Nacional de Salud Pública (MX), 2012 5. Lindberg N, Stevens V, Vega-Lopez S, Kauffman T, Rosales-Calderon M, Cervantes MA. A weightloss intervention program designed for Mexican-American women: Cultural adaptation and results. J Immigrant and Minority Health 2012;14 (6):1030-1039. 6.. Poston WS, Reeves RS, Haddock CK, Stormer S, Balasubrma-Snyam A, Satterwhite O. et al. Weight loss in Obese Mexican Americans treated for 1-year with orlistat and lifestyle modification. Int J Obes Metab Disord 2003;27(12):1486-1493. 7.. Willett WC, Dietz WH, Colditz GA. Guidelines for healthy weight. N Engl J Med 1999; 341(6):427 434. 8.. Lindstrom J, Uusitupa M. Lifestyle intervention, diabetes, and cardiovascular disease. Lancet 2008;371(9626):1731 1733. 9.. United States Department of Health and Human Services. The National Health and Nutrition Examination Survey. United States Department of Health and Human Services; 2001-2006. 10. Weiss EC, Glauska DA, Kettel Khan I, Gillespie C, Serdula HK. Weight regain in US adults who 4
experienced substantial weight loss, 1999-2002. Am J Prev Med 2007; 33(1):34-40. 11. Moyer VA. U.S. Preventive Services Task Force. Screening for and management of obesity in adults: U.S. Preventive Task Force recommendation statement. Ann Intern Med 2012;157(5):373-378. 12. Post RE, Mainous AG, Gregorie SH et al. The influence of physician acknowledgment of patients' weight status on patient perceptions of overweight and obesity in the United States. Arch Intern Med 2011;171(4):316-321.. 5
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