Validity assessment of self-reported weight and its correction process among Mexican adult women of reproductive age

Objective

We aimed to evaluate the agreement between self-reported weight (SRW) and measured weight (MW) in adult women of reproductive age, identify characteristics associated with the difference between SRW and MW (DW), and develop a correction procedure for SRW.

Methods

We used data from 3,452 non-pregnant or non-lactating adult women who participated in the Mexican Family Life Survey. Standardized personnel asked women about their weight before measuring weight and height. We conducted a Bland-Altman analysis for agreement and adjusted linear regression models for sociodemographic characteristics.

Results

Mean DW was -0.59±3.21 kg. Difference varied according to Body Mass Index (BMI) and region of residence (p< 0.05). Correction model for log-MW, included the log-SRW, age group (18–34 and 35–49 years), interaction term (age × SRW), log-height, Southern region, and living with a partner. Based on self-reported weight, we observed an overestimation of underweight/normal weight prevalence and an underestimation of overweight or obesity prevalence.

Conclusion

SRW has limitations to be considered as an alternative to MW among women of reproductive age with specific characteristics. Our proposed correction equation may decrease SRW imprecision improving the estimation of overweight and obesity. We suggest that studies consider and adjust the possible bias associated with weight misreporting on health outcomes.

The obesogenic environment around elementary schools: food and beverage marketing to children in two Mexican cities

Background

Unhealthy environments and food advertisements are major determinants of childhood obesity. Recent regulation has banned unhealthy foods from schools in Mexico. However, currently there is no regulation limiting exposure to food marketing around schools. Thus, our objective was to analyze the characteristics of food advertising practices around 60 elementary schools in two cities and to evaluate compliance with the Pan American Health Organization (PAHO) recommendations and the local food industry self-regulatory marketing code.

Methods

Data were collected during the period of October 2012 to March 2013. A random sample of elementary schools was selected from two Mexican cities. Using geographic information systems, we drew a 100-m-diameter buffer around each school. Trained personnel obtained photographs to assess the locations and types of food advertisements. Our results were stratified by school type and by indicators of compliance with the PAHO and industry recommendations. We developed a multivariate negative binomial regression model to determine factors predicting the number of advertisements around schools.

Results

The number of advertisements was significantly higher around public schools than around private schools (6.5 ± 5.6 vs. 2.4 ± 3.5, p < 0.05). Printed posters were the most common type of marketing medium (97%), showing mostly sugar-sweetened beverages, sweet breads, candies, and bottled water. Promotions, such as special prices or gifts, were included on 30% of printed posters. Food advertising practices were often in compliance with industry recommendations (83%) but not with those from the PAHO (32%) (p < 0.001).

Conclusion

Our results support the importance of monitoring the obesogenic environment and identifying policy tools to protect children from food marketing not only inside schools but also around them, particularly in lower income communities.

Usual Intake of Added Sugars and Saturated Fats Is High while Dietary Fiber Is Low in the Mexican Population

BACKGROUND

The Mexican National Health and Nutrition Survey (ENSANUT) was carried out in 2012. Information from the survey is used to design and evaluate food and nutrition policies in Mexico.

OBJECTIVE

The objective of this study was to estimate the usual intake of energy and macronutrients in the Mexican population by using the ENSANUT 2012.

METHODS

Twenty-four-hour recall interviews were administered to a nationally representative subsample of 10,096 individuals aged ≥1 y from the ENSANUT 2012. Usual intake distributions and the prevalence of inadequate intakes were estimated by using the Iowa State University method. Student's t tests and tests on the equality of proportions were used to compare usual intakes and prevalence of inadequacy across socioeconomic status, area (rural or urban), and region of residence (North, Center, or South).

RESULTS

Energy and macronutrient intakes and indicators of dietary adequacy are presented for children (ages 1-4 y and 5-11 y), adolescents (12-19 y), and adults (≥20 y). At the national level, the estimated mean fiber intake was below the Adequate Intake for all population subgroups, suggesting inadequacies. The estimated proportion with a usual added sugars intake of >10% of total energy intake was >64% in all age groups. The proportion with a usual saturated fat intake of >10% of total energy intake was estimated to be >78% in children, >66% in adolescents, and >50% in adults. Overall, fiber intake was lower and intakes of saturated fat and added sugars were higher in urban compared with rural areas, in the North compared with South regions, and among those with high compared with low socioeconomic status (P < 0.05).

CONCLUSIONS

Fiber intake is lower and added sugar and saturated fat intakes are higher than recommended for >50% of the Mexican population aged ≥1 y. These results highlight the importance of improving the diets of the overall population to reduce the risk of noncommunicable chronic diseases.

Usual Dietary Energy Density Distribution Is Positively Associated with Excess Body Weight in Mexican Children

BACKGROUND

Studies suggest a positive association between dietary energy density (DED) and body weight in adults, but evidence in children is inconclusive.

OBJECTIVE

The objective of this study was to compare usual DED distributions of nonoverweight vs. overweight or obese (OW/O) Mexican children.

METHODS

The study used 24-h recall (24HR) data from 2367 children aged 5-11 y from the 2012 Mexican National Health and Nutrition Survey (ENSANUT 2012). Repeated 24HR measures were obtained in a random sample (∼10%) to estimate usual intake distributions by using the Iowa State University (PC-Side) method. Implausible dietary reports were identified. Multivariate linear regression models were used to evaluate the relation between DED and body mass index status and to compare results with and without PC-Side adjustment and restriction to plausible reporters.

RESULTS

A total of 35.1% of the children in the sample were OW/O. The usual DED mean was ∼175 kcal/100 g in both the complete sample and the plausible reporters subsample. Regression models adjusted by PC-Side and for potential confounders showed higher DED in OW/O relative to nonoverweight children for both plausible reporters (9.7 kcal/100 g; n = 1452, P < 0.0001) and the complete sample (7.9 kcal/100 g; n = 2367, P < 0.0001). The DED difference in plausible reporters translates into 88 additional kilocalories in daily energy intake of OW/O children. In the absence of PC-side adjustment, the difference was significant for plausible reporters (P < 0.05) but not for the complete sample (P > 0.10).

CONCLUSIONS

A positive association between usual DED and OW/O was found in Mexican children. The association was stronger when only plausible reporters were considered. This suggests that there is a need for strategies to reduce energy density in the diet of Mexican children.

Caloric beverage consumption patterns in Mexican children

BACKGROUND

Mexico has seen a very steep increase in child obesity level. Little is known about caloric beverage intake in this country as well as all other countries outside a few high income countries. This study examines overall patterns and trends in all caloric beverages from two nationally representative surveys from Mexico.

METHODS

The two nationally representative dietary intake surveys (1999 and 2006) from Mexico are used to study caloric beverage intake in 17, 215 children. The volume (ml) and caloric energy (kcal) contributed by all beverages consumed by the sample subjects were measured. Results are weighted to be nationally representative.

RESULTS

The trends from the dietary intake surveys showed very large increases in caloric beverages among pre-school and school children. The contribution of whole milk and sugar-sweetened juices was an important finding. Mexican pre-school children consumed 27.8% of their energy from caloric beverages in 2006 and school children consumed 20.7% of their energy from caloric beverages during the same time. The three major categories of beverage intake are whole milk, fruit juice with various sugar and water combinations and carbonated and noncarbonated sugared-beverages.

CONCLUSION

The Mexican government, greatly concerned about obesity, has identified the large increase in caloric beverages from whole milk, juices and soft drinks as a key target and is initiating major changes to address this problem. They have already used the data to shift 20 million persons in their welfare and feeding programs from whole to 1.5% fat milk and in a year will shift to nonfat milk. They are using these data to revise school beverage policies and national regulations and taxation policies related to an array of less healthful caloric beverages.