Predicted impact of banning nonessential, energy-dense food and beverages in schools in Mexico: A microsimulation study.

BACKGROUND: Childhood obesity is a growing concern worldwide. School-based interventions have been proposed as effective means to improve nutritional knowledge and prevent obesity. In 2023, Mexico approved a reform to the General Education Law to strengthen the ban of sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools and surroundings. We aimed to predict the expected one-year change in total caloric intake and obesity prevalence by introducing the ban of NEDFBs sales in schools, among school-aged children and adolescents (6 to 17 years old) in Mexico. METHODS AND FINDINGS: We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and then estimated total energy intake (TEI) per day. The TEI after the intervention was estimated under 4 scenarios: (1) using national data to inform the intervention effect; (2) varying law compliance; (3) using meta-analytic data to inform the intervention effect size on calories; and (4) using national data to inform the intervention effect by sex and socioeconomic status (SES). We used Hall's microsimulation model to estimate the potential impact on body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools. We found that children could reduce their daily energy intake by 33 kcal/day/person (uncertainty interval, UI, [25, 42] kcal/day/person), reducing on average 0.8 kg/person (UI [0.6, 1.0] kg/person) and 1.5 percentage points (pp) in obesity (UI [1.1, 1.9] pp) 1 year after implementing the law. We showed that compliance will be key to the success of this intervention: considering a 50% compliance the intervention effect could reduce 0.4 kg/person (UI [0.3, 0.5] kg/person). Our sensitivity analysis showed that the ban could reduce body weight by 1.3 kg/person (UI [0.8, 1.8] kg/person) and up to 5.4 kg/person (UI [3.4, 7.5] kg/person) in the best-case scenario. Study limitations include assuming that obesity and the contribution of NEDFBs consumed at school remain constant over time, assuming full compliance, and not considering the potential effect of banning NEDFBs in stores near schools. CONCLUSIONS: Even in the most conservative scenario, banning sales of NEDFBs in schools is expected to significantly reduce obesity, but achieving high compliance will be key to its success. WHY WAS THIS STUDY DONE?: - School-based interventions have been recognized as effective means to improve nutritional knowledge and prevent obesity-related diseases.- In December 2023, the Chamber of Representatives of Mexico approved an amendment that strengthens and updates the General Education Law (Article 75) and nutritional guidelines to ban the sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools. WHAT DID THE RESEARCHERS DO AND FIND?: - We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and total energy intake (TEI) per day.- We used microsimulation modeling to predict body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools.- Our modeling study suggests that an important impact on obesity prevalence can be expected if the law is implemented and enforced as intended. WHAT DO THESE FINDINGS MEAN?: - If successful, this law could serve as an example beyond Mexico on how to achieve changes in body weight through school food regulation.- An important limitation of our main scenario is that we assumed full compliance of schools with the law, yet lower compliance will reduce its impact. We also did not consider historical trends on obesity or NEDFBs consumed in schools during our 1 year simulation, and we considered only the ban impact inside schools, excluding effects near and outside schools.

Maternal and Offspring Fatty Acid Desaturase Variants, Prenatal DHA Supplementation, and Dietary n-6:n-3 Fatty Acid Ratio in Relation to Cardiometabolic Health in Mexican Children.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) in fatty acid desaturase (FADS) genes may modify dietary fatty acid requirements and influence cardiometabolic health (CMH). OBJECTIVES: We evaluated the role of selected variants in maternal and offspring FADS genes on offspring CMH at the age of 11 y and assessed interactions of genotype with diet quality and prenatal docosahexaenoic acid (DHA) supplementation. METHODS: We used data from offspring (n = 203) born to females who participated in a randomized controlled trial of DHA supplementation (400 mg/d) from midgestation to delivery. We generated a metabolic syndrome (MetS) score from body mass index, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, and fasting glucose and identified 6 distinct haplotypes from 5 offspring FADS SNPs. Dietary n-6 (ω-6):n-3 fatty acid ratios were derived from 24-h recall data (n = 141). We used generalized linear models to test associations of offspring diet and FADS haplotypes with MetS score and interactions of maternal and offspring FADS SNP rs174602 with prenatal treatment group and dietary n-6:n-3 ratio on MetS score. RESULTS: Associations between FADS haplotypes and MetS score were null. Offspring SNP rs174602 did not modify the association of prenatal DHA supplementation with MetS score. Among children with TT or TC genotype for SNP rs174602 (n = 88), those in the highest n-6:n-3 ratio tertile (>8.61) had higher MetS score relative to the lowest tertile [<6.67) (Δ= 0.36; 95% confidence interval (CI): 0.03, 0.69]. Among children with CC genotype (n = 53), those in the highest n-6:n-3 ratio tertile had a lower MetS score relative to the lowest tertile (Δ= -0.23; 95% CI: -0.61, 0.16). CONCLUSIONS: There was evidence of an interaction of offspring FADS SNP rs174602 with current dietary polyunsaturated fatty acid intake, but not with prenatal DHA supplementation, on MetS score. Further studies may help to determine the utility of targeted supplementation strategies and dietary recommendations based on genetic profile.

Trends in the contribution of greenhouse gas emissions from food and beverage purchases in Mexico: 1989-2020.

BACKGROUND: Assessing the trends in dietary GHGE considering the social patterning is critical for understanding the role that food systems have played and will play in global emissions in countries of the global south. Our aim is to describe dietary greenhouse gas emissions (GHGE) trends (overall and by food group) using data from household food purchase surveys from 1989 to 2020 in Mexico, overall and by education levels and urbanicity. METHODS: We used cross-sectional data from 16 rounds of Mexico's National Income and Expenditure Survey, a nationally representative survey. The sample size ranged from 11,051 in 1989 to 88,398 in 2020. We estimated the mean total GHGE per adult-equivalent per day (kg CO2-eq/ad-eq/d) for every survey year. Then, we estimated the relative GHGE contribution by food group for each household. These same analyses were conducted stratifying by education and urbanicity. RESULTS: The mean total GHGE increased from 3.70 (95%CI: 3.57, 3.82) to 4.90 (95% CI 4.62, 5.18) kg CO2-eq/ad-eq/d between 1989 and 2014 and stayed stable between 4.63 (95% CI: 4.53, 4.72) and 4.89 (95% CI: 4.81, 4.96) kg CO2-eq/ad-eq/d from 2016 onwards. In 1989, beef (19.89%, 95% CI: 19.18, 20.59), dairy (16.87%, 95% CI: 16.30, 17.42)), corn (9.61%, 95% CI: 9.00, 10.22), legumes (7.03%, 95% CI: 6.59, 7.46), and beverages (6.99%, 95% CI: 6.66, 7.32) had the highest relative contribution to food GHGE; by 2020, beef was the top contributor (17.68%, 95%CI: 17.46, 17.89) followed by fast food (14.17%, 95% CI: 13.90, 14.43), dairy (11.21%, 95%CI: 11.06, 11.36), beverages (10.09%, 95%CI: 9.94, 10.23), and chicken (10.04%, 95%CI: 9.90, 10.17). Households with higher education levels and those in more urbanized areas contributed more to dietary GHGE across the full period. However, households with lower education levels and those in rural areas had the highest increase in these emissions from 1989 to 2020. CONCLUSIONS: Our results provide insights into the food groups in which the 2023 Mexican Dietary Guidelines may require to focus on improving human and planetary health.

Caloric reductions needed to achieve obesity goals in Mexico for 2030 and 2040: A modeling study.

BACKGROUND: In Mexico, obesity prevalence among adults increased from 23% in 2000 to 36% in 2018, approximately. Mexico has not defined short- or long-term obesity goals, obscuring the level of effort required to achieve a relevant impact. We aimed to explore potential obesity goals for 2030 and 2040 in Mexico and to estimate the required caloric reductions to achieve them. METHODS AND FINDINGS: We obtained anthropometric and demographic information on the Mexican adult population (age ≥20 years) from the Health and Nutrition Surveys conducted in 2000, 2006, 2012, 2016, and 2018 (n = 137,907). Each survey wave is cross-sectional, multistage, and representative of the Mexican population at the national, regional, and urban/rural levels. Obesity prevalence was projected for 2030 and 2040 by combining population projections of energy intake by socioeconomic status (SES) with a weight-change microsimulation model taking into account individual-level information on sex, age, physical activity, and initial body weight and height. If current trends continue, Mexico's obesity prevalence is expected to increase from 36% (95% CI 35% to 37%) in 2018 to 45% (uncertainty interval [UI] 41% to 48%) in 2030 and to 48% (UI 41% to 55%) in 2040. Based on expert opinion, we identified 3 obesity goals scenarios: (1) plausible (38% in 2030 and 36% in 2040); (2) intermediate (33% in 2030 and 29% in 2040); and (3) ideal based on the average prevalence of Organization for Economic Co-operation and Development countries (OECD; 19%). We estimated the caloric reductions needed to achieve the goal scenarios using the microsimulation model. Obesity was projected to increase more rapidly in the low SES (around 34% in 2018 to 48% (UI 41% to 55%) in 2040), than in the middle (around 38% to 52% (UI 45% to 56%)), or high SES group (around 36% to 45% (UI 36% to 54%)). Caloric reductions of 40 (UI 13 to 60), 75 (UI 49 to 95), and 190 (UI 163 to 215) kcal/person/day would be needed to reach the plausible, intermediate, and the ideal (OECD) average scenarios for 2030, respectively. To reach the 2040 goals, caloric reductions of 74 (UI 28 to 114), 124 (UI 78 to 169), and 209 (UI 163 to 254) kcal/person/day would be required, respectively. Study limitations include assuming a constant and sedentary physical activity level, not considering cohort-specific differences that could occur in the future, and assuming the same caloric trends under no intervention and the obesity goal scenarios. CONCLUSIONS: To reach the 3 obesity goals in 2040, caloric reductions between 74 and 209 kcal/day/person would be needed in Mexico. A package of new and stronger interventions should be added to existing efforts such as food taxes and warning labels on non-nutritious food.

SARS-CoV-2 seroprevalence and vaccine coverage from August to November 2021: A nationally representative survey in Mexico.

We aimed to estimate self-reported vaccine coverage and SARS-CoV-2 anti-N and anti-S seroprevalence in Mexico overall and for five vaccine types. We used a nationally representative survey with 7236 dried blood spot samples for adults 18 years and older collected from August to November 2021. Anti-N and anti-S seroprevalence were estimated adjusting for the sensitivity and specificity of the immunoassay test. A multivariate Poisson regression model was used to estimate seroprevalence by vaccine type and by age group adjusting for confounders and test performance. Vaccination coverage was 74%, being higher in women compared to men, high socioeconomic status (SES) compared to low and middle SES, graduates compared to people with high school, and formal workers compared to other employment statuses. Anti-N seroprevalence was 59.2%, compared to 84.1% anti-S seroprevalence. Anti-S seroprevalence was higher for vaccinated than unvaccinated participants. All vaccines were associated with more than 70% anti-S seroprevalence, with the lowest being observed for CoronaVac and Ad5-nCoV. Fully vaccinated participants over 60 years presented a lower seroprevalence (77.6%) compared to younger adults (91.1%), with larger differences for ChAdOx1 and CoronaVac vaccines. Between August and November 2021, three out of four Mexican adults had been vaccinated. Vaccination was associated with a higher positivity to anti-S antibodies. While antibodies do not reflect immunity, our results suggest that booster doses should be offered to people over 60 years of age and to adults who received Ad5-nCoV or CoronaVac as primary vaccination schemes.

Longitudinal patterns of breastfeeding and its association with adiposity and subjective indicators of satiety/appetite in the first 2 years of life.

Evidence about the association between breastfeeding and its duration with growth, appetite and satiety indicators, and adiposity in low and middle-income countries facing nutritional transition is scarce. The aim of this study was to evaluate the association between longitudinal patterns of breastfeeding (exclusive [EBF] and continued [CBF]) with adiposity and growth, and the mediating role of appetite and satiety indicators in these associations in Mexican children during the first 2 years of life. Information from 378 mother-child pairs from the MAS-Lactancia birth cohort was analysed. Information was collected at birth and at months 1, 3, 6, 9, 12, 18 and 24 of life. Duration of EBF and CBF was computed. Linear mixed models were used to assess the association of EBF and CBF with growth and adiposity. Path analysis was used for mediation analysis. Compared with the reference group (EBF duration <1 month), males with >3 to ≤6 months of EBF had less abdominal circumference (ß = -0.66, p = 0.05), Z-score weight-for-length (ß = -0.17, p = 0.19) and length-for-age (ß = -0.49, p < 0.01). Participants without CBF beyond 6 months had higher BMI Z-score (ß = 0.19, p < 0.01), abdominal circumference (ß = 0.62, p < 0.01) and skinfold sum (ß = 0.80, p = 0.09), and o difference in length-for-age. For EBF, mediation was confirmed for satiety responsiveness on the association with BMI Z-Score, for food fussiness for the association with abdominal circumference and length-for-age Z-score, and enjoyment of food on the association with length-for-age Z-score. For CBF, mediation was confirmed for food fussiness in the association with length-for-age. This study suggests that a longer exposure to EBF and CBF is associated with lower adiposity in children under 2 years of age, and that this association could be partially mediated by appetite and satiety indicators.

Prevalencia de prediabetes y diabetes en México: Ensanut 2022.

OBJETIVO: Estimar la prevalencia de prediabetes y diabetes en la población adulta mexicana. Material y métodos. Se utilizó información de la submuestra de adultos de la Encuesta Nacional de Salud y Nutrición 2022 con una muestra de sangre de 10 ml. Se excluyeron 150 individuos con ayuno menor a 8 horas y cuatro personas con diabetes gestacional. La muestra final fue de 1 945 adultos que expande a 78.3 millones de adultos. RESULTADOS: La prevalencia de prediabetes fue de 22.1%, y de diabetes diagnosticada y no diagnosticada de 12.6 y 5.8%, respectivamente, lo que resulta en una prevalencia de diabetes total de 18.3%. Conclusión. La diabetes en México es muy prevalente e implica un reto importante para el sistema de salud. Se requieren acciones contundentes para prevenir la enfermedad, mejorar el tamizaje, el diagnóstico oportuno y el control de la enfermedad.

Ovarian activity and reproductive responses of lactating Angus cows due to a mineral supplementation throughout a timed AI protocol.

Two experiments were conducted to evaluate the effect of intramuscular administration of minerals during a TAI program on the reproductive responses of lactating Angus cows. All cows (n=353) were subjected to a 9-day TAI program based on CIDR insertion plus injections of estradiol, cloprostenol, and eCG, and then TAI 48 h later. In experiment 1, two groups were randomly created, one control with a placebo injection (CON, n=109), and the second received 10 mL of Fosfosan® (MIN, n=172) on day 0 of the synchronization. Conception rate (66.9 vs. 55%) and estrus percentage (55.8 vs. 44%) were higher (P≤0.05) in MIN than in CON cows. Given these results, a second experiment was conducted randomly assigning the cows to two treatments (n=36 each): a single injection of 10 mL of Fosfosan® (MIN-O) on day 0 or two injections of 10 mL of Fosfosan® (MIN-T) on synchronization days 0 and 7. Four cows of each treatment were randomly selected to be scanned with transrectal ultrasound before and during the synchronization protocol to assess ovarian structures and cyclicity, and at day 39 post-TAI for pregnancy diagnosis. Also, blood samples were obtained for the determination of serum minerals and progesterone (P4) concentrations. The number of mineral injections did not affect conception rate (P≥0.1229) conception rate, serum mineral and P4 concentrations, number, and size of emerging follicles, or follicle size according to 1 to 4 classifications. The MIN-T promoted (P<0.05) earlier follicular wave emergence than MIN-O. However, MIN-O cows had a dominant follicle of 15.12 mm, which is more significant (P<0.05) than that in MIN-T cows (13.5 mm). In conclusion, providing a single mineral injection of Fosfosan® at the start of a TAI program is an excellent reproductive strategy in lactating Angus cows to improve the dominant follicle growth, estrus response, and conception rate.

Fraction of COVID-19 hospitalizations and deaths attributable to chronic diseases.

Evidence shows that chronic diseases are associated with COVID-19 severity and death. This study aims to estimate the fraction of hospitalizations and deaths from COVID-19 attributable to chronic diseases associated to poor nutrition and smoking among adults who tested positive to COVID-19 in Mexico. We analyzed 1,006,541 adults aged ≥20 who tested positive for COVID-19 from March 23 to December 5, 2020. Six chronic diseases were considered: obesity, chronic obstructive pulmonary disease (COPD), hypertension, diabetes, cardiovascular disease, and chronic kidney disease (CKD). We calibrated the database using a bias quantification method to consider undiagnosed disease cases. To estimate the total impact of multiple diseases, we defined a multimorbidity variable according to the number of diseases. Risks of hospitalization and death were estimated with Poisson regression models and used to calculate population attributable fractions (PAFs). Chronic diseases accounted for to 25.4% [95% CI: 24.8%-26.1%], 28.3% (95% CI: 27.8%-28.7%) and 15.3% (95% CI: 14.9%-15.7%) of the hospitalizations among adults below 40, 40-59, and 60 years and older, respectively. For COVID-19-related deaths, 50.1% (95% CI: 48.6%-51.5%), 40.5% (95% CI: 39.7%-41.3%), and 18.7% (95% CI, 18.0%-19.5%) were attributable to chronic diseases in adults under 40, 40-59, and 60 years and older, respectively. Chronic diseases linked to poor nutrition and smoking could have contributed to a large burden of hospitalization and deaths from COVID-19 in Mexico, particularly among younger adults. Medical and structural interventions to curb chronic disease incidence and facilitate disease control are urgently needed.

Diet cost and quality using the Healthy Eating Index-2015 in adults from urban and rural areas of Mexico.

OBJECTIVE: To assess the association between diet cost and quality by place of residence. DESIGN: We analysed cross-sectional data of the National Health and Nutrition Survey-2012. Diet cost was estimated by linking dietary data, obtained from a 7-d SFFQ, with municipality food prices, which were derived from a national expenditure survey. Diet quality was assessed using the Healthy Eating Index-2015 (HEI-2015). Association between quintiles of diet cost and HEI-2015 was assessed using linear regression analysis. SETTINGS: Mexico. PARTICIPANTS: 2438 adults (18-59 years). RESULTS: Diet cost was positively associated with diet quality (HEI-2015) in urban but not in rural areas. Compared with quintile (Q1) of cost, the increment in diet quality score was 1·17 (95 % CI -0·06, 4·33) for Q2, 2·14 (95 % CI -0·06, 4·33) for Q3, 4·70 (95 % CI 2·62, 6·79) for Q4 and 6·34 (95 % CI 4·20, 8·49) for Q5 (P-trend < 0·001). Individuals in rural v. urban areas on average have higher quality diets at lower cost with higher intakes of whole grains and beans and lower intakes of Na, added sugars and saturated fats. Living in the South, being indigenous and having low socio-economic status were also associated with higher quality diets. CONCLUSIONS: Diet cost was positively associated with diet quality, but only in urban areas. Further studies are needed to understand the relation between diet cost and quality in rural areas. To improve overall diet quality in Mexico, strategies that aim to reduce the cost of high-quality diets should consider the heterogeneity by place of residence.

Dietary intake of the Mexican population: comparing food group contribution to recommendations, 2012-2016.

OBJECTIVE: To estimate energy contribution (EC) of food groups in 2016, to compare consumption against Mexican Dietary Guidelines, and to examine changes in EC from 2012 to 2016. MATERIALS AND METHODS: We analyzed 24-hour dietary recalls from the 2012 and 2016 National Health and Nutrition Surveys (Ensanut). Foods and beverages were clas-sified into eight food groups: cereals, legumes, dairy, meats, fruit and vegetables, fats and oils, sugar-sweetened beverages, and high in saturated fat and added sugar (HSFAS) products. RESULTS: Cereals had the highest EC (30.1%), followed by meats (15.9%), HSFAS products (15.5%), and SSBs (10.5%). Fruits and vegetables, and legumes had the lowest contribu-tion with 6.4 and 3.8%, respectively. SSBs, meats, and HSFAS products were 250, 59 and 55% above the recommended intake, respectively. CONCLUSIONS: This analysis confirms the need to generate a food environment conducive to a healthier diet.

Nutrient composition of mealtimes and its association with the energy intake of subsequent meals among Mexican adults.

The composition of the diet influences energy intake by affecting satiety. Macronutrients have a hierarchical effect on satiety, where proteins have the greatest influence, followed by carbohydrates and fats. Alcohol consumption has also shown an effect on increasing energy intake in subsequent meals. Most of this evidence comes from studies under controlled conditions but, it is not clear if effects of diet composition are maintained or counteracted by other determinants of EI in real life. In this paper, we described the diet composition by mealtime in a sample of free-living Mexican adults, as well as evaluated its association with the energy intake in subsequent meals between- and within-subjects. We used information from a national cross-sectional survey of the urban Mexican population. Dietary information was collected by an automated multiple-pass 24-h recall and all participants had information from three non-consecutive days (two weekdays and one weekend). We analyzed information from adults from 20 years and older and used mixed-effects hybrid models that isolate the intra-subject, from the between-subject associations using a substitution approach. We found that alcohol and added sugars were associated with an increased EI between- and within-subjects, while fiber was associated with a decreased EI in subsequent meals within-subjects. Between-subjects, the higher intake of proteins was associated with a decrease in EI, whereas carbohydrates were associated with an increased EI in subsequent meals. We concluded that the composition of the diet at one mealtime predicted EI in subsequent meals of free-living subjects. Understanding the effects of diet composition could guide strategies to reduce EI and obesity prevention.

Progesterone supplementation in Holstein heifers subjected to cooling and timed AI during summer: physiological and reproductive variables and thyroid hormone concentrations.

Our aim was to evaluate the effects of progesterone supplementation after fixed-time artificial insemination (FTAI) on physiological and reproductive variables and serum thyroid hormone concentrations of cooled Holstein heifers during a hot summer season. Sixty-nine Holstein heifers were randomly assigned to three treatments: (1) heifers under visual estrus detection and inseminated according to AM-PM rule (n = 23; control (C)), (2) heifers subjected to FTAI after estrus synchronization using a CIDR insert (n = 24; FTAI group), and (3) heifers treated as the FTAI group plus progesterone supplementation between the day 4 and 14 post-insemination with a reused CIDR device (n = 22; FTAI+SP4 group). All heifers were cooled daily with misting and fans. Physiological variables were measured; likewise, blood samples were collected to determine serum progesterone, thyroxine, and triiodothyronine concentrations. Both respiration rate and rectal temperature were similar among treatments. Conception rate was greater (P < 0.05) in C (65.2%) and FTAI+SP4 (59.1%) heifers than in FTAI heifers (33.3%). Serum triiodothyronine and progesterone concentrations of FTAI+SP4 heifers were similar to those of C heifers but greater (P < 0.05) than those of FTAI heifers. In conclusion, progesterone supplementation post-insemination increased conception rate and serum progesterone concentrations without affecting thermoregulation capacity in Holstein heifers subjected to FTAI and cooling during a hot summer season.

Predicting obesity reduction after implementing warning labels in Mexico: A modeling study.

BACKGROUND: In October 2019, Mexico approved a law to establish that nonalcoholic beverages and packaged foods that exceed a threshold for added calories, sugars, fats, trans fat, or sodium should have an "excess of" warning label. We aimed to estimate the expected reduction in the obesity prevalence and obesity costs in Mexico by introducing warning labels, over 5 years, among adults under 60 years of age. METHODS AND FINDINGS: Baseline intakes of beverages and snacks were obtained from the 2016 Mexican National Health and Nutrition Survey. The expected impact of labels on caloric intake was obtained from an experimental study, with a 10.5% caloric reduction for beverages and 3.0% caloric reduction for snacks. The caloric reduction was introduced into a dynamic model to estimate weight change. The model output was then used to estimate the expected changes in the prevalence of obesity and overweight. To predict obesity costs, we used the Health Ministry report of the impact of overweight and obesity in Mexico 1999-2023. We estimated a mean caloric reduction of 36.8 kcal/day/person (23.2 kcal/day from beverages and 13.6 kcal/day from snacks). Five years after implementation, this caloric reduction could reduce 1.68 kg and 4.98 percentage points (pp) in obesity (14.7%, with respect to baseline), which translates into a reduction of 1.3 million cases of obesity and a reduction of US$1.8 billion in direct and indirect costs. Our estimate is based on experimental evidence derived from warning labels as proposed in Canada, which include a single label and less restrictive limits to sugar, sodium, and saturated fats. Our estimates depend on various assumptions, such as the transportability of effect estimates from the experimental study to the Mexican population and that other factors that could influence weight and food and beverage consumption remain unchanged. Our results will need to be corroborated by future observational studies through the analysis of changes in sales, consumption, and body weight. CONCLUSIONS: In this study, we estimated that warning labels may effectively reduce obesity and obesity-related costs. Mexico is following Chile, Peru, and Uruguay in implementing warning labels to processed foods, but other countries could benefit from this intervention.

Self-perception of dietary quality and adherence to food groups dietary recommendations among Mexican adults.

BACKGROUND: Mexicans' adherence to food group's dietary recommendations is low and an inaccurate self-perception of dietary quality might perpetuate this low adherence. Our aim was to compare the intake and the adherence to the dietary recommendations for several food groups, subgroups, and to an overall Mexican Diet Quality Index (MxDQI), among those that perceived their diet as healthy vs. those that did not. METHODS: We analyzed data from 989 subjects 20-59 y old from the nationally representative Mexican National Health and Nutrition Survey 2016. Dietary intake was collected with one 24-h recall and a repeated recall in 82 subjects. Self-perception of dietary quality was evaluated with the following question "Do you consider that your diet is healthy? (yes/no)". We used the National Cancer Institute method to estimate the usual intake. We compared the mean intake adjusted by sociodemographic variables and the percentage of adherence according to the self-perception of dietary quality among the whole sample and in sociodemographic subpopulations. RESULTS: Sixty percent perceived their diet as healthy, and their adherence to recommendations was low [20% for fruits and vegetables, < 8% for legumes, seafood and SSBs, and ~ 50% for processed meats and high in saturated fat and/or added sugar (HSFAS) products]. The mean number of recommendations they met was 2.8 (out of 7) vs. 2.6 among the rest of the population (p > 0.05), and the MxDQI score was 40 vs. 37 (out of 100 points). The only food groups and subgroups with a statistically significant difference between those that perceived their diet as healthy vs. unhealthy were fruits [38 g/d (95% CI 3, 73)], fruit juices [27 g/d (95% CI 2, 52)], industrialized SSBs [- 35 kcal/d (- 70, - 1)] and salty snacks [- 40 kcal/d (- 79, - 1)]. Other differences were small or inconsistent across subgroups of the population. CONCLUSIONS: Those that perceived their diet as healthy only had a slightly healthier diet than the rest of the population, moreover, their adherence to recommendations was very low. Hence, it is necessary to improve their nutrition knowledge.

Malnutrition in all its forms by wealth, education and ethnicity in Latin America: who are more affected?

OBJECTIVE: To summarise the findings from this supplemental issue on the distribution of malnutrition (stunting/short stature, anaemia and overweight) by wealth, education and ethnicity within and between ten Latin American countries. DESIGN: We retrieved information from each country's article and estimated the average difference in the prevalence of malnutrition between groups. We estimated the associations between countries' malnutrition prevalence and GDP, percentage of women with high education and percentage of non-indigenous ethnicity. SETTING: Nationally representative surveys from ten Latin American countries conducted between 2005 and 2017. PARTICIPANTS: Children (<5 years), adolescent women (11-19 years) and adult women (20-49 years). RESULTS: Socially disadvantaged groups (low wealth, low education and indigenous ethnicity) had on average 15-21 (range across indicators and age groups) percentage points (pp) higher prevalence of stunting/short stature and 3-11 pp higher prevalence of anaemia. For overweight or obesity, adult women with low education had a 17 pp higher prevalence; differences were small among children <5 years, and results varied by country for adolescents by education, and for adults and adolescents by wealth and ethnicity. A moderate and strong correlation (-0·58 and -0·71) was only found between stunting/short stature prevalence and countries' GDP per capita and percentage of non-indigenous households. CONCLUSIONS: Overweight was equally distributed among children; findings were mixed for ethnicity and wealth, whereas education was a protective factor among adult women. There is an urgent need to address the deep inequalities in undernutrition and prevent the emerging inequalities in excess weight from developing further.

Characterization of small-scale dairy farms and its relation to water use efficiency in the Mexicali Valley, Mexico.

A survey was completed to determine water use by small-scale dairy farms in Mexicali Valley of Mexico and to associate it with dairy production parameters. Mexicali Valley surrounds the capital city of the state Baja California, Mexicali. Sixty-one smallholders were interviewed in person in this rural area of northwestern Mexico. On average, small dairy holders had more than 20 years of experience and were ~ 55 years of age; people working on their farms are especially relatives. A low percentage was literate (20%), and they belong to a local dairy association. Milk yield/cow/year does not reach 4000 kg of milk and 75% of producers do not follow a defined management program for their cattle. Hand-milking is still practiced by 27% of the producers, and there is a general lack of infrastructure to maintain milk in a refrigerated state so that there is a very high risk of zoonotic diseases. Water use efficiency (WUE) was linearly correlated (P < 0.05) with total irrigated area, but not with animal production parameters. Regression equations constructed to explain WUE exhibited low adjustment, and WUE was not associated (P > 0.05) with milk yield. Small dairy producers in Mexicali Valley are in a generally poor situation with low water use practices; however, required more government support to increase their benefits from this livestock activity.

Height Trajectory During Early Childhood Is Inversely Associated with Fat Mass in Later Childhood in Mexican Boys.

BACKGROUND: Childhood obesity continues to be a global health problem. Previous research suggests that linear growth retardation or stunting during early childhood increases the risk of obesity, but others have reported that rapid linear growth poses a greater concern than early nutritional status. OBJECTIVE: The objective of this study was to determine if growth trajectories are associated with body composition at age 8-10 y. METHODS: Study participants consisted of 255 girls and 281 boys who participated in a follow-up of the Prenatal Omega-3 Fatty Acid Supplementation and Child Growth and Development (POSGRAD) Study. Sex-specific latent height class (LHC) trajectories were derived from 11 measures of height from birth to 5 y of age and used to calculate 3 distinct growth classes for boys (low, intermediate, and high) and 2 distinct classes for girls (low and high). Body composition at age 8-10 y was estimated using bioelectrical impedance analysis. Multivariable linear regression analysis was used to determine the relationship between growth trajectory classes and fat mass (FM) and fat-free mass (FFM) in late childhood, controlling for confounding factors. RESULTS: In girls, there were no significant associations between LHC and FM or FFM. In boys, relative to the intermediate LHC, the low LHC had higher FM (ß = 0.69 kg; 95% CI: 0.26-1.11 kg) and the high LHC had lower FM (ß = -0.40 kg; 95% CI: -0.76 to -0.05 kg). Boys in the low LHC had significantly less FFM (ß = -0.69 kg; 95% CI: -1.11 to -0.26 kg), and boys in the high LHC had more FFM (ß = 0.40 kg; 95% CI: 0.05-0.76 kg) compared with the intermediate LHC. CONCLUSION: Gain in height among boys, but not girls, in early childhood was associated with lower adiposity in late childhood compared with children with a slower rate of growth. Clinical trial registration number: NCT00646360.

Reduction in purchases of energy-dense nutrient-poor foods in Mexico associated with the introduction of a tax in 2014.

In 2014, an 8% tax on energy-dense nutrient-poor foods was implemented in Mexico with the aim of reducing its consumption. This paper estimated changes in household purchases of taxed food. We used the latest five waves of the nationally representative Mexican Income and Expenditure Survey (2008, 2010, 2012, 2014 and 2016). The analytic sample comprises 154,777 households. We estimated changes in purchases based on a before and after comparison. Results show a reduction in purchases of taxed food of -5.4 g/week per capita, equivalent to a relative reduction of -5.3% in the 2014 and 2016 waves compared to the 2008, 2010 and 2012 rounds. The largest relative reductions were in urban areas (-6.9%), among households with children (-7.0%), households where the head had an intermediate educational level (-9.9%) and the southern region (-14.8%). We did not find a significant reduction in rural areas. While there is a large heterogeneity, the fiscal instrument has been effective in reducing taxed food purchases and has generated substantial revenue that could be used to finance policies for the prevention and treatment of obesity.

Did high sugar-sweetened beverage purchasers respond differently to the excise tax on sugar-sweetened beverages in Mexico?

OBJECTIVE: To estimate changes in taxed and untaxed beverages by volume of beverage purchased after a sugar-sweetened beverage (SSB) tax was introduced in 2014 in Mexico. DESIGN: We used household purchase data from January 2012 to December 2015. We first classified the sample into four groups based on pre-tax purchases of beverages: (i) higher purchases of taxed beverages and lower purchases of untaxed beverages (HTLU-unhealthier); (ii) higher purchases of both types of beverages (HTHU); (iii) lower purchases of taxed and untaxed beverages (LTLU); and (iv) lower purchases of taxed beverages and higher purchases of untaxed beverages (LTHU-healthier). Next, we estimated differences in purchases after the tax was implemented for each group compared with a counterfactual based on pre-tax trends using a fixed-effects model. SETTING: Areas with more than 50 000 residents in Mexico. PARTICIPANTS: Households (n 6089). RESULTS: The HTLU-unhealthier and HTHU groups had the largest absolute and relative reductions in taxed beverages and increased their purchases of untaxed beverages. Households with lower purchases of untaxed beverages (HTLU-unhealthier and LTLU) had the largest absolute and relative increases in untaxed beverages. We also found that among households with higher purchases of taxed beverages, the group with lowest socio-economic status had the greatest reduction in purchases of taxed beverages. CONCLUSIONS: Evidence associating the SSB tax with larger reductions among high purchasers of taxed beverages prior to the tax is relevant, as higher SSB purchasers have a greater risk of obesity, diabetes and other cardiometabolic outcomes.