Beyond Wishful Thinking: Integrating Consumer Preferences in the Assessment of Dietary Recommendations

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.

The cost of diversity in livestock feed rations

This study investigates the financial cost of increasing the diversity of cereal grains in livestock feed rations. We first develop a nonlinear mathematical programming model that determines the least-cost composition of livestock feed rations of one metric ton that have at least the same energy and nutrient content as a reference feed ration. We then add into the model a diversity constraint using the Simpson Index of diversity to examine how changes in the diversity of the commodities in the ration affect the cost of the ration while maintaining the ration's energy and nutrient content at a reference ration value. We apply the model to cereal grain feed rations for livestock in 153 countries, using reference rations that depict the historical composition of cereal grain feed rations offered to livestock in each country. Results suggest that a one percent change in ration diversity changed the ration cost (i.e., the cost-diversity elasticity) from -0.67% to 1.41% (average = -0.02%) across all countries. Our results suggest that changes in ration diversity can come at a financial cost, but this financial cost appears negligible in many countries. This negligible cost could provide the feed sector more encouragement to diversify its feed supply and potentially become more resilient to price and production shocks.

Addressing the low consumption of fruit and vegetables in England: a cost-effectiveness analysis of public policies

BACKGROUND

Most adults do not meet the recommended intake of five portions per day of fruit and vegetables (F&V) in England, but economic analyses of structural policies to change diet are sparse.

METHODS

Using published data from official statistics and meta-epidemiological studies, we estimated the deaths, years-of-life lost (YLL) and the healthcare costs attributable to consumption of F&V below the recommended five portions per day by English adults. Then, we estimated the cost-effectiveness from governmental and societal perspectives of three policies: a universal 10% subsidy on F&V, a targeted 30% subsidy for low-income households and a social marketing campaign (SMC).

FINDINGS

Consumption of F&V below the recommended five portions a day accounted for 16 321 [10 091-23 516] deaths and 238 767 [170 350-311 651] YLL in England in 2017, alongside £705 951 [398 761-1 061 559] million in healthcare costs. All policies would increase consumption and reduce the disease burden attributable to low intake of F&V. From a societal perspective, the incremental cost-effectiveness ratios were £22 891 [22 300-25 079], £16 860 [15 589-19 763] and £25 683 [25 237-28 671] per life-year saved for the universal subsidy, targeted subsidy and SMC, respectively. At a threshold of £20 000 per life-year saved, the likelihood that the universal subsidy, the targeted subsidy and the SMC were cost-effective was 84%, 19% and 5%, respectively. The targeted subsidy would additionally reduce inequalities.

CONCLUSIONS

Low intake of F&V represents a heavy health and care burden in England. All dietary policies can improve consumption of F&V, but only a targeted subsidy to low-income households would most likely be cost-effective.

Intrinsic alterations in peripheral neutrophils from cystic fibrosis newborn piglets

BACKGROUND

The hallmark of the cystic fibrosis (CF) lung disease is a neutrophil dominated lung environment that is associated to chronic lung tissue destruction and ultimately the patient's death. It is unclear whether the exacerbated neutrophil response is primary related to a defective CFTR or rather secondary to chronic bacterial colonization and inflammation. Here, we hypothesized that CF peripheral blood neutrophils present intrinsic alteration at birth before the start of an inflammatory process.

METHODS

Peripheral blood neutrophils were isolated from newborn CFTR^+/+ and CFTR^-/- piglets. Neutrophils immunophenotype was evaluated by flow cytometry. Lipidomic and proteomic profile were characterized by liquid chromatography/tandem mass spectrometry (LC-MS/MS), intact cell matrix-assisted laser desorption/ionization mass spectrometry (ICM-MS) followed by top-down high-resolution mass spectrometry (HRMS), respectively. The ability of CF neutrophils to kill pseudomonas aeruginosa was also evaluated.

RESULTS

Polyunsaturated fatty acid metabolites analysis did not show any difference between CFTR^+/+ and CFTR^-/- neutrophils. On the other hand, a predictive mathematical model based on the ICM-MS proteomic profile was able to discriminate between both genotypes. Top-down proteomic analysis identified 19 m/z differentially abundant masses that corresponded mainly to proteins related to the antimicrobial response and the generation of reactive oxygen species (ROS). However, no alteration in the ability of CFTR^-/- neutrophils to kill pseudomonas aeruginosa in vitro was observed.

CONCLUSIONS

ICM-MS demonstrated that CFTR^-/- neutrophils present intrinsic alterations already at birth, before the presence of any infection or inflammation.

Impacts of Reducing UK Beef Consumption Using a Revised Sustainable Diets Framework

The impact of beef consumption on sustainability is a complex and evolving area, as sustainability covers many areas from human nutrient adequacy to ecosystem stability. Three sustainability assessment frameworks have been created to help policy makers unpack the complexities of sustainable food systems and healthy sustainable dietary change. However, none of these frameworks have yet to be applied to a case study or individual policy issue. This paper uses a hybrid version of the sustainability assessment frameworks to investigate the impact of reducing beef consumption (with a concurrent increase in consumption of plant-based foods, with a focus on legumes) on sustainability at a UK level. The aim of this paper is to understand the applicability of these overarching frameworks at the scale of an individual policy. Such an assessment is important, as this application of previously high-level frameworks to individual policies makes it possible to summarise, at a glance, the various co-benefits and trade-offs associated with a given policy, which may be of particular value in terms of stakeholder decision-making. We find that many of the proposed metrics found within the sustainability assessment frameworks are difficult to implement at an individual issue level; however, overall they show that a reduction in beef consumption and an increase in consumption of general plant-based foods, with a focus around legumes production, would be expected to be strongly beneficial in five of the eight overarching measures which were assessed.

Utilization of a Diet Optimization Model in Ensuring Adequate Intake among Pregnant Women in Selangor, Malaysia

Achieving nutritional requirements for pregnant women in rural or suburban households while maintaining the intake of local and culture-specific foods can be difficult. Usage of a linear programming approach can effectively generate diet optimization models that incorporate local and culturally acceptable menus. This study aimed to determine whether a realistic and affordable diet that achieves recommended nutrient intakes for pregnant women could be formulated from locally available foods in Malaysia. A cross-sectional study was conducted to assess the dietary intake of 78 pregnant women using a 24-h dietary recall and a 3-day food record. A market survey was also carried out to estimate the cost of raw foods that are frequently consumed. All linear programming analyses were done using Excel Solver to generate optimal dietary patterns. Our findings showed that the menus designed from diet optimization models using locally available foods would improve dietary adequacy for the seven food groups based on the Malaysian Dietary Guidelines 2010 (MDG 2010) and the 14 nutrients based on Recommended Nutrient Intake 2017 (RNI 2017) in pregnant women. However, inadequacies remained for iron and niacin, indicating that these nutrients may require supplementation.

Economic assessment of nutritional recommendations: A comment

This is a comment on the paper by Irz et al. (2015) in this journal, on nutritional recommendations. Irz et al. (2015) propose to compute the cost of a nutritional constraint as the consumer loss of surplus, derived from their observed choices. Introducing behavioral biases into an extended version of their model, I show that their proposed methodology implicitly assumes that consumer dietary choices do not involve any health considerations. The cost per quality-adjusted life year that they compute should be corrected by the size of the bias of consumers to be compared with benchmark evaluations.

Assessing Sustainable Food and Nutrition Security of the EU Food System—An Integrated Approach

Steering the EU food system towards a sustainability transformation requires a vast and actionable knowledge base available to a range of public and private actors. Few have captured this complexity by assessing food systems from a multi-dimensional and multi-level perspective, which would include (1) nutrition and diet, environmental and economic outcomes together with social equity dimensions and (2) system interactions across country, EU and global scales. This paper addresses this gap in food systems research and science communication by providing an integrated analytical approach and new ways to communicate this complexity outside science. Based on a transdisciplinary science approach with continuous stakeholder input, the EU Horizon2020 project ‘Metrics, Models and Foresight for European SUStainable Food And Nutrition Security’ (SUSFANS) developed a five-step process: Creating a participatory space; designing a conceptual framework of the EU food system; developing food system performance metrics; designing a modelling toolbox and developing a visualization tool. The Sustainable Food and Nutrition-Visualizer, designed to communicate complex policy change-impacts and trade-off questions, enables an informed debate about trade-offs associated with options for change among food system actors as well as in the policy making arena. The discussion highlights points for further research related to indicator development, reach of assessment models, participatory processes and obstacles in science communication.

Translation of nutrient recommendations into personalized optimal diets for Chinese urban lactating women by linear programming models

Background

Lactating women need to consume a high-quality diet to replete nutrient stores depleted during pregnancy and to ensure sufficient nutrition for breastfeeding. However, several studies reported suboptimal dietary quality and nutrient intake of lactating mothers in China. The objectives of this study was to apply dietary modeling method to develop individualized optimal diets, which meet the nutrient requirements for lactating women in urban China.

Methods

Data were collected from a sample of 576 lactating women from 0 to 240 days postpartum during the Maternal Infant Nutrition Growth study conducted between 2011 and 2012 in three cities including Beijing, Guangzhou, and Suzhou. Dietary intake data were collected with an interviewer-administered 24-h survey. Linear programming was applied to develop dietary plans that meet recommendations for lactation women in the China Dietary Reference Intakes 2013 and the Chinese Dietary Guideline 2016, while with least deviation from the observed dietary intake.

Results

Through dietary modeling, individual optimal diets were developed for 576 lactating women. The optimal diets met all the food and nutrient intake constraints set in the linear programming models. The large difference between observed and optimized diets suggests that the nutrient needs of lactating mothers in China may only be met after substantial dietary changes. In addition, the analysis showed that it was difficult to meet the recommended intake for six nutrients: vitamin A, vitamin B1, vitamin B6, calcium, selenium, and dietary fiber. Moreover, four clusters in the optimized diets were identified by K-means cluster analysis. The four clusters confirmed that the optimal diets developed by linear programming could characterize the variety in dietary habits by geographical regions and duration of lactation.

Conclusion

Linear programming could help translate nutrient recommendations into personal diet advices for a sample of urban lactating mothers from China. The study showed that dietary modeling is helpful to support healthy eating of lactation women by translating dietary guidelines into personalized meal plans.

Trial registration

The Maternal Infant Nutrition Growth study was registered in ClinicalTrials.gov with identifier NCT01971671. Registration date October 29, 2013.

Multi-indicator sustainability assessment of global food systems

Food systems are at the heart of at least 12 of the 17 Sustainable Development Goals (SDGs). The wide scope of the SDGs call for holistic approaches that integrate previously “siloed” food sustainability assessments. Here we present a first global-scale analysis quantifying the status of national food system performance of 156 countries, employing 25 sustainability indicators across 7 domains as follows: nutrition, environment, food affordability and availability, sociocultural well-being, resilience, food safety, and waste. The results show that different countries have widely varying patterns of performance with unique priorities for improvement. High-income nations score well on most indicators, but poorly on environmental, food waste, and health-sensitive nutrient-intake indicators. Transitioning from animal foods toward plant-based foods would improve indicator scores for most countries. Our nation-specific quantitative results can help policy-makers to set improvement targets on specific areas and adopt new practices, while keeping track of the other aspects of sustainability.

The development of sustainable food systems requires an understanding of potential trade-off between various objectives. Here, Chaudhary et al. examine how different nations score on food system performance across several domains, including environment, nutrition, and sociocultural wellbeing.

The Goal of Adequate Nutrition: Can It Be Made Affordable, Sustainable, and Universal?

Until about 1900, large proportions of the world population endured hunger and poverty. The 20th century saw world population increase from 1.6 to 6.1 billion, accompanied and to some extent made possible by rapid improvements in health standards and food supply, with associated advances in agricultural and nutrition sciences. In this paper, I use the application of linear programming (LP) in preparation of rations for farm animals to illustrate a method of calculating the lowest cost of a human diet selected from locally available food items, constrained to provide recommended levels of food energy and nutrients; then, to find a realistic minimum cost, I apply the further constraint that the main sources of food energy in the costed diet are weighted in proportion to the actual reported consumption of food items in that area. Worldwide variations in dietary preferences raise the issue as to the sustainability of popular dietary regimes, and the paper reviews the factors associated with satisfying requirements for adequate nutrition within those regimes. The ultimate physical constraints on food supply are described, together with the ways in which climate change may affect those constraints. During the 20th century, food supply increased sufficiently in most areas to keep pace with the rapid increase in world population. Many challenges will need to be overcome if food supply is to continue to meet demand, and those challenges are made more severe by rising expectations of quality of life in the developing world, as well as by the impacts of climate change on agriculture and aquaculture.