Sustainability of Diets in Mexico: Diet Quality, Environmental Footprint, Diet Cost, and Sociodemographic Factors

Mexican national dietary guidelines promote less costly and environmentally sustainable diets

The 2023 Mexican Healthy and Sustainable Dietary Guidelines (HSDG 2023) were developed to include all dimensions of sustainability. Here we compare the environmental impact and cost of diets based on the HSDG 2023, current diets and the Mexican-adapted EAT healthy reference diet. Diets following HSDG 2023 are 21% less expensive, require 30% less land to be produced and have 34% less carbon emissions than current diets-particularly in Mexico City and other urban areas with higher prevalence of Westernized diets. This is driven by reduced animal-source food, especially red meat, and ultra-processed foods. In south-rural areas, the water footprint and cost of diets following HSDG 2023 were higher than those of current diets owing to increased intake of nuts, fruits and vegetables not offset by lower meat consumption (which is already close to recommendations). Diet environmental impact and cost could be further reduced with the Mexican-adapted EAT healthy reference diet compared with the HSDG 2023.

Multicriteria Measures to Assess the Sustainability of Diets: A Systematic Review

CONTEXT

Assessing the overall sustainability of a diet is a challenging undertaking requiring a holistic approach capable of addressing the multicriteria nature of this concept.

OBJECTIVE

The aim was to identify and summarize the multicriteria measures used to assess the sustainability characteristics of diets reported at the individual level by healthy adults.

DATA SOURCES

Articles were identified via PubMed, Scopus, and Web of Science. The search strategy consisted of key words and MeSH terms, and was concluded in September 2022, covering references in English, Spanish, and Portuguese.

DATA EXTRACTION

This systematic review followed the PRISMA guidelines. The search identified 5663 references, from which 1794 were duplicates. Two reviewers independently screened the titles and abstracts of each of the 3869 records and the full-text of the 144 references selected. Of these, 7 studies met the inclusion criteria.

DATA ANALYSIS

A total of 6 multicriteria measures were identified: 3 different Sustainable Diet Indices, the Quality Environmental Costs of Diet, the Quality Financial Costs of Diet, and the Environmental Impact of Diet. All of these incorporated a health/nutrition dimension, while the environmental and economic dimensions were the second and the third most integrated, respectively. A sociocultural sustainability dimension was included in only 1 of the measures.

CONCLUSION

Despite some methodological concerns in the development and validation process of the identified measures, their inclusion is considered indispensable in assessing the transition towards sustainable diets in future studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022358824.

Factors Affecting Anemia among Women of Reproductive Age in Mexico: A Mixed-Methods Country Case Study

BACKGROUND

In Mexico, anemia prevalence among women of reproductive age (WRA) decreased from 16.4% in 2006 to 11.6% in 2012, only to increase to 18.3% in 2016. The factors associated with this fluctuation are uncertain.

OBJECTIVE

We conducted a systematic in-depth assessment of the quantitative and qualitative determinants of anemia among WRA in Mexico between 2006 and 2018.

METHODS

Using multivariate stepwise linear regression, we analyzed Mexico's Encuesta Nacional de Salud y Nutrición (ENSANUT) surveys from 2006, 2012, and 2018 to identify determinants of WRA anemia. We also conducted a review of anemia-relevant programs and policies, including financing documents, and conducted in-depth interviews and focus group discussions with key stakeholders in Mexico.

RESULTS

Among non-pregnant women (NPW) 15-49 years, mean hemoglobin (Hb) increased from 13.8 g/dL in 2006 to 14.0 g/dL in 2012, decreasing to 13.2 g/dL in 2018 (p<0.001). Inequities by geographical region and household wealth persisted throughout this period, with household wealth, urban residence and gravidity emerging as significant predictors of Hb among NPW. Qualitative analyses generally supported these findings. The most discussed program was Progresa-Oportunidades-Prospera (POP), where most resources for health were invested and most participants acknowledged that its cancellation in 2019 would lead to worsening in health and nutrition among the poor. Financing analyses showed a drop of funding for nutrition-related programs between 2014 and 2018. Cultural norms around gender roles were still prevalent, along with increasing rates of teenage pregnancy.

CONCLUSIONS

Anemia prevention efforts need to refocus on poverty alleviation, continuity of adequate coverage and financing of nutrition programs, especially with safety nets, and increase in uptake of family planning, especially among adolescent girls.

What factors influence sustainable and healthy diet consumption? A review and synthesis of literature within the university setting and beyond

Globally, typical dietary patterns are neither healthy nor sustainable. Recognizing the key role of dietary change in reducing noncommunicable disease risk and addressing environmental degradation, it is crucial to understand how to shift individuals toward a sustainable and healthy diet (SHD). In this literature review, we introduced the concept of a SHD and outlined the dietary behaviors necessary to transition toward SHD consumption; we reviewed the literature on factors that may influence sustainable (and unsustainable) dietary behaviors in adults; and we developed a novel scoring system to rank factors by priority for targeting in future research. Given the significant potential to promote a sustainable and healthy dietary transition on the university campus-where factors that may impact dietary behaviors can be targeted at all levels of influence (i.e., individual, interpersonal, environmental, policy)-we narrowed our focus to this setting throughout. Aided by our novel scoring system, we identified conscious habitual eating, product price, food availability/accessibility, product convenience, self-regulation skills, knowledge of animal ethics/welfare, food promotion, and eating norms as important modifiable factors that may influence university students' dietary behaviors. When scored without consideration for the university population, these factors were also ranked as highest priority, as was modified portion sizes. Our findings offer insight into factors that may warrant attention in future research aimed at promoting SHDs. In particular, the high-priority factors identified from our synthesis of the literature could help guide the development of more personalized dietary behavioral interventions within the university setting and beyond.

The Impact of Sustainability Courses: Are They Effective in Improving Diet Quality and Anthropometric Indices?

There are studies on the effect of general nutrition education on diet quality and anthropometric measurements, while studies showing the effectiveness of sustainable nutrition education, which also addresses the effect of food on the environment, are quite limited. This study aimed to investigate the effects of sustainable nutrition education on diet quality, anthropometric measurements, and the carbon footprint (CFP) and water footprint (WFP) of diet. A total of 160 university students received 1 h of sustainable nutrition education for 6 weeks. Before, at the end of, and 2 months after the courses, 24 h food consumption records were taken to assess diet quality and CFP and WFP values of diet, and Mediterranean diet (MedDiet) and Healthy Eating Index (HEI)-2020 scores were evaluated. The results of the study showed that sustainable nutrition education increased MedDiet score by 1.86 points and HEI-2020 score by 7.38 points. This education program also decreased body weight, body mass index (BMI), fat mass, and neck circumference. Sustainability education has a positive impact on calcium, potassium, and magnesium intakes, a negative impact on vitamin B12 and zinc intakes, and no effect on total protein intake. Education resulted in a 22% reduction in CFP and a 10% reduction in WFP.

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.

Measurement of diets that are healthy, environmentally sustainable, affordable, and equitable: A scoping review of metrics, findings, and research gaps

Introduction

Research on the impacts of dietary patterns on human and planetary health is a rapidly growing field. A wide range of metrics, datasets, and analytical techniques has been used to explore the role of dietary choices/constraints in driving greenhouse gas (GHG) emissions, environmental degradation, health and disease outcomes, and the affordability of food baskets. Many argue that each domain is important, but few have tackled all simultaneously in analyzing diet-outcome relationships.

Methods

This paper reviews studies published between January 2015 and December 2021 (inclusive) that examined dietary patterns in relation to at least two of the following four thematic pillars: (i) planetary health, including, climate change, environmental quality, and natural resource impacts, (ii) human health and disease, (iii) economic outcomes, including diet cost/affordability, and (iv) social outcomes, e.g., wages, working conditions, and culturally relevant diets. We systematically screened 2,425 publications by title and abstract and included data from 42 eligible publications in this review.

Results

Most dietary patterns used were statistically estimated or simulated rather than observed. A rising number of studies consider the cost/affordability of dietary scenarios in relation to optimized environmental and health outcomes. However, only six publications incorporate social sustainability outcomes, which represents an under-explored dimension of food system concerns.

Discussion

This review suggests a need for (i) transparency and clarity in datasets used and analytical methods; (ii) explicit integration of indicators and metrics linking social and economic issues to the commonly assessed diet-climate-planetary ecology relationships; (iii) inclusion of data and researchers from low- and middle-income countries; (iv) inclusion of processed food products to reflect the reality of consumer choices globally; and (v) attention to the implications of findings for policymakers. Better understanding is urgently needed on dietary impacts on all relevant human and planetary domains simultaneously.

Measuring sustainable consumer food purchasing and behavior

Consumer food purchasing and willingness to adopt a sustainable healthy diet (SHD) is a key factor affecting the sustainability of the entire food system. Studies have developed scales to measure consumer preferences for particular consumption patterns, while others have sought to empirically define the multiple dimensions of a sustainable food system (environmental, social, economic, etc.). This paper builds on these literatures by tracking consumers' SHD behaviors using a large-scale, longitudinal survey of adults in the United States and mapping them onto multiple systems-level indicators. We wanted to know whether consumers interact with the sustainability of their food along the same principles developed by experts. Our study defines 18 food purchasing behaviors that support the sustainability goals of leading scientific institutions, uses factor analysis to identify the unobserved drivers behind these behaviors, and creates SHD scores to investigate their correlations with other consumer characteristics and behaviors. Factor analysis results show consumer food purchasing is motivated by three underlying sustainability dimensions-Economic Security, Socio-Environment, and Nutrition-which are fewer constructs than often defined by academic researchers. SHD scores reveal higher adoption of behaviors that fall under Economic Security relative to the other two dimensions. All three sustainability constructs are impacted by socio-economic and demographic characteristics.

Affordable Nutrient Density in Brazil: Nutrient Profiling in Relation to Food Cost and NOVA Category Assignments

Affordable nutrient density is provided by low-cost and nutrient-rich foods. We explored nutrient density, cost, and NOVA category assignments within and across food groups in Brazil. The nutrient density of the foods (n = 591) was assessed using the Nutrient Rich Food Index (NRF9.3) based on protein, fiber, vitamin A (RAE), vitamin C, vitamin E (mg), Ca, Fe, K and Mg; and NRF6.3 score for priority nutrients: Ca, Fe, Zn, vitamin A, vitamin B12, and folate. Nutrients to limit (LIM) were saturated fat, added sugar, and sodium. Affordability was defined as the ratio of energy and/or nutrient density of foods and retail price per 100 kcal. Foods were classified as minimally processed (n = 106), processed (n = 188), ultra-processed (n = 286), and culinary ingredients (n = 11). Nutrient density was positively linked to per 100 kcal food cost. Ultra-processed foods (UPF) contained more energy, fat, sugar, and salt and had lower NRF scores compared to minimally processed (MPF) foods. UPF was also less expensive than MPF foods. Nutrient-rich foods below the median per 100 kcal costs included MPF foods, but also processed foods (PF) and UPF. Affordable nutrient-rich foods can be found in the different categories of the NOVA classification.