Compliance with nutrition standards in Mexican schools and their effectiveness: a repeated cross-sectional study

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.

Three approaches to assessing dietary quality in Mexican adolescents from 2006 to 2018 with data from national health and nutrition surveys

OBJECTIVE

To assess trends in the dietary quality of Mexican adolescents from 2006 to 2018, both overall and by sociodemographic indicators, using adaptations of the EAT-Lancet Planetary Health (PH) recommendations, optimal intake estimated by the Global Burden of Disease (GBD) and 2015 Mexican Dietary Guidelines (MDG) in nationally representative samples.

DESIGN

Using dietary data from a semi-quantitative FFQ, dietary quality indexes were constructed as adaptations of three dietary intake recommendations. Trends in adherence to recommendations were evaluated with multivariate quantile regression models with survey year as the main independent variable and adjusted for age, sex, energy intake, dwelling area, geographical region, household assets condition, and student/non-student status. P values and CI were Bonferroni-corrected.

SETTING

Mexico.

PARTICIPANTS

Non-pregnant or lactating adolescents aged 12-19 years (n 16 520).

RESULTS

Adherence to the PH index was about 40 %, GBD was nearly 35 % and MDG was about 37 %. The lowest adherences were for added sugars, sugar-sweetened beverages, nuts and seeds, red meats, processed meats, and legumes (<28 %). No 2006-2018 trends in total adherence were found in any index. Nevertheless, negative adherence trends were identified for poultry (β = -2·4), and saturated fats (β = -0·93), and positive for unsaturated oils (β = 1·23), in the PH. In MDG, relevant trends were found for plain water (β = 1·63) and foods rich in fats (β = -1·24).

CONCLUSIONS

Mexican adolescents have demonstrated poor dietary quality by these three approaches. Therefore, this population has a high-risk profile for diet-associated chronic diseases. Further research and appropriate public policies are needed.

Perspective: Mexico's Experience in Building a Toolkit for Obesity and Noncommunicable Diseases Prevention

Noncommunicable diseases (NCDs) are a leading cause of death and disability worldwide, with a higher risk of death in low- and middle-income countries. Diet and excess weight are risk factors for NCDs. In Mexico, the prevalence of overweight and obesity increased dramatically in the last 30 y and is among the highest in the world. To address this public health problem, governments and public health professionals have several policy instruments available. In this study, we present the policy instruments currently approved in Mexico, which include fiscal, informational, and authoritative tools that aim to improve the food environment and promote healthy behaviors (taxes, school food guidelines, front-of-pack labeling, marketing regulations, and dietary guidelines). These types of interventions are important in regions like Latin America, where social inequities and poor access to information are common, and individual healthy choices are often limited. These interventions target the environments in which individuals live, study, work, and seek entertainment, while limiting access to unhealthy choices and offering information to promote healthy alternatives. The Mexican experience in design, implementation, and evaluation of policies to improve the food environment can be useful for other low- and middle-income countries facing similar challenges.

Associated substitution and complementation patterns of processed discretionary foods and drinks on total energy and added sugar intake

BACKGROUND

Processed discretionary foods and drinks (industrialised sugary drinks, sweet and savoury snacks, and grain-based sweets) are often target of policies aimed at regulating the food environment. We aimed to understand if a lower intake of processed foods or drinks is associated with substitution or complementation patterns and overall intake.

METHODS

We analysed a subsample with two 24-h dietary recalls of the Mexican National Health and Nutrition Survey 2012 (358 children, 253 adolescents and 278 adults). We compared within-person, energy and added sugar intakes between days with and without consumption of each food group with fixed-effects regressions. We estimated the relative change (change in intake when not consumed/average intake when consumed × 100).

RESULTS

Processed discretionary foods were not fully substituted, as total energy was 200-400 kcal/day lower when these foods were not consumed. The change in total intake was larger than the intake when consumed (i.e., complemented) for industrialised sugary drinks in adolescents (-136%) and adults (-215%), and sweet, savoury snacks for children (-141%). The change was lower (i.e., partially substituted) for grain-based sweets among children (-78%) and adolescents (-73%). For added sugars, most processed discretionary groups were complemented.

CONCLUSIONS

Days without intake of processed discretionary foods were associated with lower total energy and lower added sugar intake compared to days when those foods were consumed. This suggests that regulatory policies to reduce the intake of processed foods could have a meaningful impact on improving the overall diet.

Childhood obesity in Mexico: Influencing factors and prevention strategies

Background

Overweight and obesity in school-age children, in Mexico as in other countries around the world, is a rapidly increasing public health problem within recent years, with important consequences for the future health of the population. Various national strategies at the individual and community level have been established to prevent these conditions, but none have yet succeeded.

Objective

To describe factors which influence overweight and obesity in school-age children five to 11 years old in Mexico, and national strategies for the prevention and management of these conditions.

Methods

The data herein is derived from six National Health and Nutrition Surveys in Mexico: 2006, 2012, 2016, 2018, 2020, and 2021. They include a total of 45,216 school-age children with complete anthropometric data (weight/height) distributed over 84 pseudo-panels defined by age, wellbeing condition class (WCC), gender, and type of locality of residence. The indicators calculated were overweight and obesity by body mass index according to World Health Organization guidelines. Predictors are food consumption indicators in five groups.

Results

The prevalence of overweight and obesity showed a positive linear trend (p < 0.001), with average annual increases of 0.41%. Increases in fruit consumption reduced the prevalence of these conditions by 6.6% (p = 0.01) and vegetable consumption reduced this by 8.3%.

Conclusions

Overweight and obesity in school-age children is a growing problem with serious repercussions for future life. New strategies are needed which focus on involving food systems, which translates to healthy and sustainable diets.

Perceived Availability of Healthy and Unhealthy Foods in the Community, Work, and Higher Education Settings across Five Countries: Findings from the International Food Policy Study 2018

BACKGROUND

Food environments play a key role in dietary behavior and vary due to different contexts, regulations, and policies.

OBJECTIVES

This study aimed to characterize the perceived availability of healthy and unhealthy foods in 3 different settings in 5 countries.

METHODS

We analyzed data from the 2018 International Food Policy Study, a cross-sectional survey of adults (18-100 y, n = 22,824) from Australia, Canada, Mexico, the United Kingdom (UK), and the USA. Perceived availability of unhealthy (junk food and sugary drinks) and healthy foods (fruit or vegetables, healthy snacks, and water) in the community, workplace, and university settings were measured (i.e. not available, available for purchase, or available for free). Differences in perceived availability across countries were tested using adjusted multinomial logistic regression models.

RESULTS

Across countries, unhealthy foods were perceived as highly available in all settings; in university and work settings unhealthy foods were perceived as more available than healthy foods. Australia and Canada had the highest perceived availability of unhealthy foods (range 87.5-90.6% between categories), and the UK had the highest perceived availability of fruits and vegetables for purchase (89.3%) in the community. In university and work settings, Mexico had the highest perceived availability for purchase of unhealthy foods (range 69.9-84.9%). The USA and the UK had the highest perceived availability of fruits and vegetables for purchase (65.3-66.3%) or for free (21.2-22.8%) in the university. In the workplace, the UK had high perceived availability of fruits and vegetables for purchase (40.2%) or for free (18.5%), and the USA had the highest perceived availability of junk food for free (17.3%).

CONCLUSIONS

Across countries, unhealthy foods were perceived as highly available in all settings. Variability between countries may reflect differences in policies and regulations. Results underscore the need for the continuation and improvement of policy efforts to generate healthier food environments.

Identification and Evaluation of Tools Utilised for Measuring Food Provision in Childcare Centres and Primary Schools: A Systematic Review

BACKGROUND

Children aged 2-11 years spend significant hours per week in early childhood education and care (ECEC) and primary schools. Whilst considered important environments to influence children's food intake, there is heterogeneity in the tools utilised to assess food provision in these settings. This systematic review aimed to identify and evaluate tools used to measure food provision in ECEC and primary schools.

METHODS

The Preferred Reporting Items for Systematic Reviews (PRISMA) was followed. Publications (2003-2020) that implemented, validated, or developed measurement tools to assess food provision within ECEC or primary schools were included. Two reviewers extracted and evaluated studies, cross checked by a third reviewer and verified by all authors. The Academy of Nutrition and Dietetics Quality Criteria Checklist (QCC) was used to critically appraise each study.

RESULTS

Eighty-two studies were included in the review. Seven measurement tools were identified, namely, Menu review; Observation; Weighed food protocol; Questionnaire/survey; Digital photography; Quick menu audit; and Web-based menu assessment. An evidence-based evaluation was conducted for each tool.

CONCLUSIONS

The weighed food protocol was found to be the most popular and accurate measurement tool to assess individual-level intake. Future research is recommended to develop and validate a tool to assess service-level food provision.

Strategies and interventions for healthy adolescent growth, nutrition, and development

Adolescence is a pivotal point in the life course, characterised by transformative physical, cognitive, and emotional growth, an openness to change, and a drive to reshape the social environment. It offers unique opportunities to adopt changes in diet and physical activity that can persist into later life. Yet pre-existing nutritional problems, including micronutrient deficiencies, food insecurity, and poor-quality diets, persist at the same time as adolescents face the rapid emergence of an obesity epidemic. Adolescent growth and nutrition has been largely overlooked in intervention and policy research. Most intervention studies have emphasised micronutrient supplementation, with few taking into account the multiple drivers of adolescent diets. This Series paper highlights that effective interventions and policies will need to cut across sectors; be supported by multifaceted and multilevel policy; and extend across education, health, food systems, social protection, and digital media. Better data standardisation and systems will be essential in coordinating and monitoring these responses. In a context of shifts in planetary ecosystems and commercial drivers, resilient food systems will need to both ensure access to healthy and affordable foods and provide the infrastructure and incentives for continuing physical activity. Intergenerational partnerships with young people will be essential in bringing about transformative change and ensuring that food policies reflect their needs and aspirations.

Association between density of stores and purchases of ultra-processed food and sugar-sweetened beverages in Mexico

In Mexico, purchases of ultra-processed food and sugar-sweetened beverages (SSB) and the number of large supermarkets, discount and convenience stores are growing. The objective of this study was to analyze the association between the density of different types of food stores and ultra-processed food and SSB (taxed beverages) purchases in a representative sample of Mexican households. Results show that the density of convenience stores (national and in urban areas) was significantly associated with higher purchases of ultra-processed food and that supermarkets were marginally associated. Our findings are stronger for beverages where we found that convenience stores, discount stores, small grocery stores and stores speciliazed in selling candies, popsicles, soft drinks and other food were associated with higher purchases of taxed beverages. Mexico should implement or strengthen current policies to reduce purchases of ultra-processed food and sugar-sweetened beverages and to regulate the location and density of stores.

Sugar consumption in schoolchildren from southern Spain and influence on the prevalence of obesity

Aim

The main cause of childhood overweight/obesity is an imbalance between energy intake and energy expenditure. The objective was to determine whether the intake by Spanish schoolchildren of sugars from habitually consumed foods and drinks can be related to overweight/obesity.

Methods

Subjects The study included 657 schoolchildren between 7–10 years from educational centers in Southern Spain. These children live under the influence of the Mediterranean diet. Design Participants completed an encoded questionnaire with three sections: a) data on sex, age, educational center, school year, and life/family habits, among others; b) semi-quantitative food frequency questionnaire related to the previous 12 months; and c) information on anthropometrics and physical activities.

Results

Obesity was observed in 10.9% of the children. The daily activity questionnaire showed a mean energy expenditure of 8.73 (1.33) MJ/day. The study considered foods that supply carbohydrates in any form (total carbohydrates, starch, total sugars, added sugars, and free sugars). The likelihood of overweight/obesity was significantly greater with a higher intake/day of total sugars, starch, added sugars, and free sugars. The likelihood of normal weight was significantly greater with lower energy expenditure in sedentary activities (OR = 3.03), higher energy expenditure in sports activities (OR = 1.72), and higher total activity/day measured as METs (OR = 8.31).

Conclusions

In this population, overweight/obesity was influenced by the physical activity of the children and by their intake of energy, total sugars, starch, added sugars, and free sugars. Further studies are warranted to verify this observation and explore the implications for public health policies.

Body weight impact of the sugar-sweetened beverages tax in Mexican children: A modeling study

BACKGROUND

In Mexico, a 10% tax to sugar-sweetened beverages was implemented in 2014. Projections of the potential health effect of this tax in children are not available.

OBJECTIVE

To estimate the 1-year effect of the tax on the body weight of children 5 to 17 years old, and estimated alternative scenarios with higher tax rates (20%, 30%, and 40%).

METHODS

We used a dynamical mathematical model, recalibrated to the Mexican population. Input data were obtained from the Mexican National Health and Nutrition Survey 2006 and 2012. We estimated the expected average weight reduction, stratified by category of sugar-sweetened beverages consumption.

RESULTS

With a 10% tax, we estimated an overall weight reduction of 0.26 kg for children and 0.61 kg for adolescents; in high consumers, the reduction could reach 0.50 and 0.87 kg, respectively. Higher tax rates would produce larger weight decreases; in high consumers a 40% tax would result in a reduction of 1.99 kg for children and 3.50 kg for adolescents.

CONCLUSION

The tax represents an effective component of any child or adolescent weight control program, and must be considered as part of any integrated population-level program for children and adolescent obesity prevention.

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.

Mortality attributable to sugar sweetened beverages consumption in Mexico: an update

BACKGROUND

In 2010, sugar sweetened beverages (SSBs) were estimated to cause 12% of all diabetes, cardiovascular disease (CVD) and obesity-related cancer deaths in Mexico. Using new risk estimates for SSBs consumption, we aimed to update the fraction of Mexican mortality attributable to SSBs, and provide subnational estimates by region, age, and sex.

METHODS

We used an established comparative risk assessment framework. All-cause mortality estimates were calculated from a recent pooled cohort analysis. Age- and sex-specific relative risks for SSBs-disease relationships were obtained from updated meta-analyses. Demographics and nationally representative estimates of SSBs intake were derived from the National Health and Nutrition Survey 2012; and mortality rates, from the National Institute of Statistics and Geography. Attributable mortality was calculated by estimating the population attributable fraction of each disease, with uncertainty in data inputs propagated through Monte Carlo probabilistic sensitivity analyses.

RESULTS

In Mexican adults 20 years and older, 6.9% (95%UI: 5.4-8.5) of all cause-mortality was attributable to SSBs, representing 40,842 excess deaths/year (95%UI: 31,950-50,138). Furthermore, 19% of diabetes, CVD and obesity-related cancer mortality was attributable to SSBs (95%UI: 11.0-26.5), representing 37,000 excess deaths/year (95%UI 21,240-51,045). Of these, 35.6% were diabetes-related (95%UI 16.4-52.0). Proportional burden was highest in the South (22.8%), followed by the Center (18.0%) and North (17.4%). Men aged 45-64-years in the Center region had highest proportional mortality (37.2%), followed by 20-44-year-old men living in the South (35.7%) and both men and women aged 20-44 living in the Center (34.4%).

CONCLUSIONS

Utilizing current evidence linking SSBs to cardiometabolic disease and obesity-related cancers, earlier estimates of Mexican mortality attributable to SSBs could have been underestimated. Mexico urgently needs stronger policies to reduce SSBs consumption and reduce these burdens.