Margarita Safdie

Epidemiological and nutritional transition in Mexico: rapid increase of non-communicable chronic diseases and obesity

OBJECTIVE The objective of this paper is to characterise the epidemiological and nutritional transition and their determinants in Mexico. DESIGN Age-adjusted standardised mortality rates (SMRs) due to acute myocardial infarction (AMI), diabetes mellitus and hypertension were calculated for 1980-1998. Changes in the prevalences of overweight and obesity in women and children and of dietary intake from 1988 to 1999 were also used in the analysis. Quantities of food groups purchased by adult equivalent (AE) and food expenditures away from home between 1984 and 1989 were used to assess trends. All information was analysed at the national and regional levels, and by urban and rural areas. RESULTS SMR for diabetes, AMI and hypertension increased dramatically parallel to obesity at the national and regional levels. Fat intake in women and the purchase of refined carbohydrates, including soda, also increased. DISCUSSION The results suggest that obesity is playing a role in the increased SMRs of diabetes, AMI and hypertension in Mexico. Total energy dietary intake and food purchase data could not explain the rise in the prevalence of obesity. The increases in fat intake and the purchase of refined carbohydrates may be risk factors for increased mortality. Information on physical activity was not available. CONCLUSION SMRs due to diabetes, hypertension and AMI have increased dramatically in parallel with the prevalence of obesity; therefore actions should be taken for the prevention of obesity. Reliable information about food consumption and physical activity is required to assess their specific roles in the aetiology of obesity.

Energy and nutrient intake in preschool and school age Mexican children: National Nutrition Survey 1999

OBJECTIVE To estimate energy and nutrient intake and adequacy in preschool and school age Mexican children, using the National Nutrition Survey 1999 (NNS-1999). MATERIAL AND METHODS Twenty four-h dietary recalls from pre-school (n = 1,309) and school (n = 2,611) children obtained from a representative sub-sample of the NNS-1999 were analyzed. Intakes and adequacies were estimated and compared across four regions, socio-economic strata, and between urban and rural areas, and indigenous vs. non-indigenous children. RESULTS Median energy intake in pre-school children was 949 kcal and in school children 1,377 kcal, with adequacies < 70% for both groups. Protein adequacy was > 150% in both age groups. The North and Mexico City regions had the highest fat intake and the lowest fiber intake. Children in the South region, indigenous children, and those in the lowest socio-economic stratum had higher fiber and carbohydrate intakes and the lowest fat intake. These children also showed the highest risks of inadequacies for vitamin A, vitamin C, folate, iron, zinc and calcium. CONCLUSIONS Mexico is experiencing a nutrition transition with internal inequalities across regions and socio-economic strata. Food policy must account for these differences in order to optimize resources directed at social programs. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Overweight and obesity trends in Mexican children 2 to 18 years of age from 1988 to 2006

OBJECTIVE To describe prevalences and trends of overweight and obesity/OW&OB in Mexican children from 1988 to 2006 at the national level and by relevant subpopulations. MATERIAL AND METHODS Prevalences of OW&OB in children aged 2-18 years were estimated using body mass index data from three national surveys conducted in 1988, 1999 and 2006. RESULTS Prevalences of OW&OB are high in children of all ages, particularly among school-age and adolescent groups disaggregated by regions, socioeconomic status, urban and rural areas, and ethnic groups. The overall prevalence of OW&OB in children 2 to 18 years old in 2006 was 26.3%. Prevalences by age groups were 16.7% in preschool-age, 26.2% in school-age, and 30.9% in adolescents, using the IOTF classification system. CONCLUSIONS Upward trends were observed in school-age children and adolescents at the national level and in all subpopulations.

Energy and nutrient consumption in Mexican women 12-49 years of age: analysis of the National Nutrition Survey 1999

OBJECTIVE To describe the reported energy and nutrient intake and adequacies in Mexican women. MATERIAL AND METHODS A 24-hour dietary recall was used to obtain nutrient intake in a representative sub-sample of 2,630 women from 12 to 49 years of age from the National Nutrition Survey 1999. Nutrient adequacies were estimated using the Dietary Reference Intakes and stratified according to region, area (urban or rural), socioeconomic status and obesity status (non-obese: BMI < 30 kg/m2, obese: > or = 30 kg/m2). Differences were analyzed using linear regression for complex surveys of log-transformed intake and adequacy, adjusting for multiple comparisons with the Bonferroni test. RESULTS The median national energy intake was 1,471 kcal. The Risk of Inadequacy (RI) (prevalence of adequacy < 50%) was: vitamin A: 38.3%, vitamin C: 45.5%, and folate: 34.3%. Carbohydrates, folate, iron and calcium intake was significantly higher in rural than in urban areas. The RI was higher in women of the lowest socioeconomic status tertile for all nutrients with the exception of carbohydrates and calcium. Macro-nutrient adequacies were significantly higher in non-obese women. CONCLUSIONS Differences within the country among regions, rural and urban areas, and socioeconomic status tertile reflect an increasing availability of inexpensive calorie-dense foods in marginal groups. However, total energy, cholesterol, saturated and total fat were consumed in greater quantities by women from the higher socioeconomic status tertile and from urban areas. These patterns could be a contributing factor to the rise of obesity and other non-communicable nutrition-related chronic diseases in Mexico. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Physical activity during the school day in public primary schools in Mexico City

OBJECTIVE To quantify the physical activity (PA) of students and describe the school environment surrounding PA. MATERIAL AND METHODS Between November 2005 and March 2006, in Mexico City, we conducted quantitative and qualitative observations to describe the PA and the school context. RESULTS Recess and physical education class (PE) were the only opportunities to participate in PA. PE occurred one time per week with a duration of 39.8+/-10.6 minutes which is less than national and international recommendations. Students participated in moderate-to-vigorous PA 29.2+/-17.8% of PE. The dynamics of PE did not promote the inclusion of all students or PA. During recess there was overcrowding of the school patio and no equipment for PA or organization of PA. DISCUSSION The PA of students in public schools in Mexico City can be improved by increasing the quantity and quality of PE and increasing opportunities for activity during recess.

Effect of a school-based intervention on physical activity: cluster-randomized trial.

PURPOSE Physical activity in childhood has many health benefits; however, the majority of children in many countries, including Mexico, are insufficiently active. The objective of this investigation was to test the effect of a school-based environmental intervention on the physical activity and physical fitness of students attending public primary schools in Mexico City. METHODS Twenty-seven schools were randomly assigned to basic or plus intervention or control. The basic and plus groups were exposed to school environment and policy changes to enhance physical activity. Physical activity was evaluated in 699 randomly selected fourth- and fifth-grade students by measuring school-day and all-day (24 h) steps using pedometers worn for 5 d before and after the 6-month intervention. Physical fitness was assessed by measuring the 9-min run, flexibility, and sit-ups. We calculated the average change in school-day and all-day steps and fitness measures from baseline to follow-up. Using linear regression, we tested the effect of intervention on change controlling for baseline measures and covariates and accounting for the design effect of school. Using logistic regression, we tested the effect of intervention on reaching step cutoffs at baseline and follow-up. RESULTS The plus group significantly (P < 0.05) increased school-day steps relative to control (change = 687 vs -639). Significantly (P < 0.05) more participants in the basic (25.8%) and plus (36.4%) groups reached step cutoffs during school relative to control (12.0%). The basic group significantly (P < 0.05) increased all-day steps relative to control (change = 581 vs -419). The plus group significantly (P = 0.05) increased sit-ups relative to control (change = 0.3 vs -1.7). CONCLUSIONS A school-based environmental intervention improved student physical activity during school in public schools in Mexico City.

An ecological and theoretical deconstruction of a school-based obesity prevention program in Mexico

BackgroundEcological intervention programs are recommended to prevent overweight and obesity in children. The National Institute of Public Health (INSP) in Mexico implemented a successful ecological intervention program to promote healthy lifestyle behaviors in school age children. This study assessed the integration of ecological principles and Social Cognitive Theory (SCT) constructs in this effective school-based obesity prevention program implemented in 15 elementary schools in Mexico City.MethodsTwo coders applied the Intervention Analysis Procedure (IAP) to “map” the program’s integration of ecological principles. A checklist gauged the use of SCT theory in program activities.ResultsThirty-two distinct intervention strategies were implemented in one setting (i.e., school) to engage four different target-groups (students, parents, school representatives, government) across two domains (Nutrition and Physical Activity). Overall, 47.5% of the strategies targeted the school infrastructure and/or personnel; 37.5% of strategies targeted a key political actor, the Public Education Secretariat while fewer strategies targeted parents (12.5%) and children (3%). More strategies were implemented in the Nutrition domain (69%) than Physical Activity (31%). The most frequently used SCT construct within both intervention domains was Reciprocal Determinism (e.g., where changes to the environment influence changes in behavior and these behavioral changes influence further changes to the environment); no significant differences were observed in the use of SCT constructs across domains.ConclusionsFindings provide insight into a promising combination of strategies and theoretical constructs that can be used to implement a school-based obesity prevention program. Strategies emphasized school-level infrastructure/personnel change and strong political engagement and were most commonly underpinned by Reciprocal Determinism for both Nutrition and Physical Activity.

O21: Education and Communication Strategy as Part of a Project to Prevent Obesity in Upper Elementary Children

O21 Education and Communication Strategy as Part of a Project to Prevent Obesity in Upper Elementary Children Ana Islas, EdD, Instituto Nacional de Salud Publica, 7a. Cerrada Fray Pedro de Gante #50 Col Seccion XVI Mexico, D.F. Mexico, aislas@insp.mx; Florence Theodore, PhD, ftheodore@correo.insp.mx; Marian Villanueva, MS, mavillan@insp.mx; Tiffany Gust, MS, tgust@insp.mx; Margarita Safdie, MPH, msafdie@insp.mx; Juan Rivera, PhD, jrivera@insp.mx