Juan A. Rivera

Maternal and child undernutrition: global and regional exposures and health consequences

Maternal and child undernutrition is highly prevalent in low-income and middle-income countries, resulting in substantial increases in mortality and overall disease burden. In this paper, we present new analyses to estimate the effects of the risks related to measures of undernutrition, as well as to suboptimum breastfeeding practices on mortality and disease. We estimated that stunting, severe wasting, and intrauterine growth restriction together were responsible for 2·2 million deaths and 21% of disability-adjusted life-years (DALYs) for children younger than 5 years. Deficiencies of vitamin A and zinc were estimated to be responsible for 0·6 million and 0·4 million deaths, respectively, and a combined 9% of global childhood DALYs. Iron and iodine deficiencies resulted in few child deaths, and combined were responsible for about 0·2% of global childhood DALYs. Iron deficiency as a risk factor for maternal mortality added 115 000 deaths and 0·4% of global total DALYs. Suboptimum breastfeeding was estimated to be responsible for 1·4 million child deaths and 44 million DALYs (10% of DALYs in children younger than 5 years). In an analysis that accounted for co-exposure of these nutrition-related factors, they were together responsible for about 35% of child deaths and 11% of the total global disease burden. The high mortality and disease burden resulting from these nutrition-related factors make a compelling case for the urgent implementation of interventions to reduce their occurrence or ameliorate their consequences.

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.

Early supplementary feeding and cognition : effects over two decades

The study reported in this Monograph of the effects of early supplementary feeding on cognition included two data collection periods: a longitudinal investigation spanning the years 1969-1977 and a cross-sectional follow-up carried out in 1988-1989. The study was conducted in four rural villages in Guatemala and compared the differential effects of exposure in childhood (0-7 years) to an Atole supplement (11.5 g of protein; 163 kcal) or a Fresco supplement (59 kcal) on performance on a battery of psychoeducational and information-processing tests in adolescence and young adulthood (11-24 years). In this report, particular attention is given to a cohort of subjects who were exposed to the supplement prenatally and during at least the first 2 years of postnatal life. Data on this subsample are contrasted with those on a cohort of subjects who received the supplement only after 24 months of life. The Monograph also reports results from an analysis of the supplementation effects in infancy and early childhood. Consistent differences between groups on the psychoeducational tests were observed. Adolescents from Atole villages scored significantly higher on tests of knowledge, numeracy, reading, and vocabulary than Fresco subjects. Atole was also associated with a faster reaction time in information-processing tasks. Significant interactions helped identify two groups who benefited more from the Atole treatment: those at the lowest levels of socioeconomic status and those who attained the highest levels of primary schooling. The consistent differences in test performance established in the follow-up assessment contrast sharply with the few and less pronounced between-group differences observed in the infancy and preschool periods. After close scrutiny of alternative hypotheses, it is concluded that nutritional differences provide the strongest explanation for the test performance differences observed in the follow-up between the subjects exposed to the Atole and those exposed to the Fresco supplement.

Beverage purchases from stores in Mexico under the excise tax on sugar sweetened beverages: observational study

Study question What has been the effect on purchases of beverages from stores in Mexico one year after implementation of the excise tax on sugar sweetened beverages? Methods In this observational study the authors used data on the purchase of beverages in Mexico from January 2012 to December 2014 from an unbalanced panel of 6253 households providing 205 112 observations in 53 cities with more than 50 000 inhabitants. To test whether the post-tax trend in purchases was significantly different from the pretax trend, the authors used a difference in difference fixed effects model, which adjusts for both macroeconomic variables that can affect the purchase of beverages over time, and pre-existing trends. The variables used in the analysis included demographic information on household composition (age and sex of household members) and socioeconomic status (low, middle, and high). The authors compared the predicted volumes (mL/capita/day) of taxed and untaxed beverages purchased in 2014—the observed post-tax period—with the estimated volumes that would have been purchased if the tax had not been implemented (counterfactual) based on pretax trends. Study answer and limitations Relative to the counterfactual in 2014, purchases of taxed beverages decreased by an average of 6% (−12 mL/capita/day), and decreased at an increasing rate up to a 12% decline by December 2014. All three socioeconomic groups reduced purchases of taxed beverages, but reductions were higher among the households of low socioeconomic status, averaging a 9% decline during 2014, and up to a 17% decrease by December 2014 compared with pretax trends. Purchases of untaxed beverages were 4% (36 mL/capita/day) higher than the counterfactual, mainly driven by an increase in purchases of bottled plain water. What this study adds The tax on sugar sweetened beverages was associated with reductions in purchases of taxed beverages and increases in purchases of untaxed beverages. Continued monitoring is needed to understand purchases longer term, potential substitutions, and health implications. Funding, competing interests, data sharing This work was supported by grants from Bloomberg Philanthropies and the Robert Wood Johnson Foundation and by the Instituto Nacional de Salud Pública and the Carolina Population Center. The authors have no competing interests. No additional data are available.

Energy Intake from Beverages Is Increasing among Mexican Adolescents and Adults

Little is understood about the patterns and trends in adolescent and adult beverage intake in Mexico or most other countries. Here, we used nationally representative dietary intake, income, and food expenditure surveys, which included 416 adolescents (aged 12-18 y) and 2180 adults (aged >or=19 y) from the 1999 Mexican Nutrition Survey and 7464 adolescents and 21,113 adults from the 2006 Mexican Health and Nutrition Survey. We measured the volume and energy per day contributed by all beverages consumed by the sample subjects. In 2006, Mexican adolescents and adults obtained 20.1 and 22.3%, respectively, of their energy intake from energy-containing beverages. Whole milk, carbonated and noncarbonated sugar-sweetened beverages, fruit juice with various sugar and water combinations added, and alcohol represented the 4 major categories of beverage intake. The trends from the dietary intake surveys showed very large increases in the intake of energy-containing beverages among adolescents and adults between 1999 and 2006. Income elasticities showed a high likelihood that intakes will increase as Mexican incomes continue to rise. Whereas the own-price elasticities for whole milk and sodas were both modest, intakes of these were increasing and higher than those for all other food groups. Energy intake trends and current levels of beverage intakes in Mexico are the highest recorded in a nationally representative survey and present major challenges for public health authorities.

Characterizing the epidemiological transition in Mexico: national and subnational burden of diseases, injuries, and risk factors.

Background Rates of diseases and injuries and the effects of their risk factors can have substantial subnational heterogeneity, especially in middle-income countries like Mexico. Subnational analysis of the burden of diseases, injuries, and risk factors can improve characterization of the epidemiological transition and identify policy priorities. Methods and Findings We estimated deaths and loss of healthy life years (measured in disability-adjusted life years [DALYs]) in 2004 from a comprehensive list of diseases and injuries, and 16 major risk factors, by sex and age for Mexico and its states. Data sources included the vital statistics, national censuses, health examination surveys, and published epidemiological studies. Mortality statistics were adjusted for underreporting, misreporting of age at death, and for misclassification and incomparability of cause-of-death assignment. Nationally, noncommunicable diseases caused 75% of total deaths and 68% of total DALYs, with another 14% of deaths and 18% of DALYs caused by undernutrition and communicable, maternal, and perinatal diseases. The leading causes of death were ischemic heart disease, diabetes mellitus, cerebrovascular disease, liver cirrhosis, and road traffic injuries. High body mass index, high blood glucose, and alcohol use were the leading risk factors for disease burden, causing 5.1%, 5.0%, and 7.3% of total burden of disease, respectively. Mexico City had the lowest mortality rates (4.2 per 1,000) and the Southern region the highest (5.0 per 1,000); under-five mortality in the Southern region was nearly twice that of Mexico City. In the Southern region undernutrition and communicable, maternal, and perinatal diseases caused 23% of DALYs; in Chiapas, they caused 29% of DALYs. At the same time, the absolute rates of noncommunicable disease and injury burdens were highest in the Southern region (105 DALYs per 1,000 population versus 97 nationally for noncommunicable diseases; 22 versus 19 for injuries). Conclusions Mexico is at an advanced stage in the epidemiologic transition, with the majority of the disease and injury burden from noncommunicable diseases. A unique characteristic of the epidemiological transition in Mexico is that overweight and obesity, high blood glucose, and alcohol use are responsible for larger burden of disease than other noncommunicable disease risks such as tobacco smoking. The Southern region is least advanced in the epidemiological transition and suffers from the largest burden of ill health in all disease and injury groups.

Childhood and adolescent overweight and obesity in Latin America: a systematic review

The number of children and adolescents who are overweight or obese worldwide is alarming. We did a systematic review to estimate the prevalence of overweight and obesity in children aged 0-19 years in Latin America. We searched specialised databases and seven books for relevant studies that were done in Spanish-speaking and Portuguese-speaking Latin American and Caribbean countries and published in peer-reviewed journals between January 2008, and April 2013. Indicators used were BMI (kg/m(2)) in all age groups and weight-for-height in children younger than 5 years. We identified 692 publications and included 42. Estimated prevalence of overweight in children younger than 5 years in Latin America was 7·1% with the weight-for-height WHO 2006 classification method. National combined prevalences of overweight and obesity with the WHO 2007 classification method ranged from 18·9% to 36·9% in school-age children (5-11 years) and from 16·6% to 35·8% in adolescents (12-19 years). We estimated that 3·8 million children younger than 5 years, 22·2-25·9 million school-age children, and 16·5-21·1 million adolescents were overweight or obese. Overall, between 42·5 and 51·8 million children aged 0-19 years were affected-ie, about 20-25% of the population. Although undernutrition and obesity coexist in the region, policies in most countries favour prevention of undernutrition, and only a few countries have implemented national policies to prevent obesity. In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents are urgently needed throughout Latin America.

History and Design of the INCAP Longitudinal Study (1969–77) and its Follow-Up (1988–89)

This is an overview of the design and methods of the INCAP longitudinal study (1969-77) and its follow-up study (1988-89). The first study had the objective of assessing the effects of intrauterine and preschool malnutrition on growth and mental development. To achieve this, food supplements were provided to pregnant women and young children residing in four Gautemalan villages. Two villages were given a high-protein, high-energy drink and two were provided a no-protein, low-energy drink. Both supplements contained vitamins and minerals. Longitudinal information was collected during the first seven years of life on physical growth, mental development, attendance and consumption of supplement, home diet, morbidity and on characteristics of the family. Health and nutrition data on mothers also were collected. The INCAP follow-up study was a cross-sectional evaluation of former participants of the first study and was carried out when the subjects were 11-27 y old. The hypothesis of the INCAP follow-up study was that improved nutrition in early childhood leads to enhanced human capital formation in adolescents and adults. Data were collected on physical growth and body composition, maturation, work capacity, intellectual performance and school achievement.

Nutrition in Early Life and the Fulfillment of Intellectual Potential

The effects of early supplementary feeding on cognition are investigated using data collected during two periods in four Guatemalan villages. The first was the Institute of Nutrition of Central America and Panama (INCAP) longitudinal study from 1969 to 1977 and the second was a cross-sectional follow-up of former participants carried out in 1988-1989. The principal objective of these studies was to assess the differential effect of two dietary supplements, Atole containing 163 kcal/682 kJ and 11.5 g protein per cup or 180 mL and Fresco containing 59 kcal/247 kJ and 0 g protein per cup, that were given to mothers, infants and young children. Performance was assessed on a battery of psychoeducational and information processing tests that were administered during adolescence. Consistent differences between groups were observed on psychoeducational tests. Subjects receiving Atole scored significantly higher on tests of knowledge, numeracy, reading and vocabulary than those given Fresco. Atole ingestion also was associated with faster reaction time in information processing tasks. In addition, there were significant interactions between type of dietary supplement and socioeconomic status (SES) of subjects. In Atole villages, there were no differences in performance between subjects in the lowest and highest SES categories. On the other hand, performance in Fresco villages was best in the highest compared with the lowest SES group. After close scrutiny of alternative hypotheses, it is concluded that dietary changes produced by supplementation provide the strongest explanation for the test performance differences observed in the follow-up between subjects exposed to Atole and those exposed to Fresco supplementation.

Effects of Docosahexaenoic Acid Supplementation During Pregnancy on Gestational Age and Size at Birth: Randomized, Double-Blind, Placebo-Controlled Trial in Mexico

Background The need for omega-3 fatty acids, especially docosahexaenoic acid (DHA), during pregnancy has received much attention, but evidence of effects on birth outcomes is limited. Objective To evaluate whether prenatal DHA supplementation increases gestational age and birth size. Methods We conducted a double-blind, randomized, placebo-controlled trial in Cuernavaca, Mexico. We randomly assigned 1,094 pregnant women (18 to 35 years of age; median DHA dietary intake, 55 mg/day) to 400 mg/day of algal DHA or placebo from 18 to 22 weeks of gestation through delivery. Birth outcomes (968 live births and 5 stillbirths) were ascertained from hospital records within 24 hours of delivery. Results Intention-to-treat analysis showed no differences between the control and DHA group (all p > .05) in mean gestational age (39.1 + 1.7 and 39.0 ± 1.9 weeks, respectively), weight (3.20 + 0.47 and 3.21 ± 0.45 kg, respectively), length (50.3 ± 2.7 and 50.3 ± 2.3 cm, respectively) and head circumference (34.3 ± 1.8 and 34.3 ± 1.5 cm, respectively) at birth. Offspring of supplemented primigravidae (n = 370) were heavier (difference, 99.4 g; 95% CI, 5.5 to 193.4) and had larger head circumferences (difference, 0.5 cm; 95% CI, 0.1 to 0.9) than controls; the differences in multigravidae (n = 603) were −53.3 g (95% CI, −126.8 to 20.2) and −0.2 cm (95% CI, −0.4 to 0.1), respectively (p < .05 for heterogeneity). Conclusions Prenatal DHA supplementation of primigravid women may result in increased birth size in a population where dietary DHA intakes are very low. Benefits of the intervention on infant health and neurodevelopment are under study.