Least-cost Diets Research Articles

Diet affordability: a key dimension in the assessment of sustainable food systems and healthy diets.

A promulgated global shift toward a plant-based diet is largely in response to a perceived negative environmental impact of animal food production, but the nutritional adequacy and economic implications of plant-sourced sustainable healthy dietary patterns need to be considered. This paper reviews recent modeling studies using Linear Programming to determine the respective roles of animal- and plant-sourced foods in developing a least-cost diet in the United States and New Zealand. In both economies, least-cost diets were found to include animal-based foods, such as milk, eggs, fish, and seafood, to meet the energy and nutrient requirements of healthy adults at the lowest retail cost. To model a solely plant-based least-cost diet, the prevailing costs of all animal-sourced foods had to be increased by 1.1 to 11.5 times their original retail prices. This led to the inclusion of fortified plant-based foods, such as fortified soymilk, and a plant-based diet that was considerably (34-45%) more costly. The first-limiting essential nutrients were mostly the vitamins and minerals, with special focus on pantothenic acid, zinc, and vitamin B-12, when transitioning from an animal- and plant-containing least-cost diet to a plant-only based least-cost diet. Modeled least-cost diets based on contemporary food costs include animal-sourced foods, at least for developed high-income US and NZ food economies, and potentially for developing low- and middle-income countries, such as Indonesia. Modeling of least-cost diets that consist exclusively of plant-based foods is feasible, but at a higher daily diet cost, and these diets are often close to limiting for several key nutrients. Diet affordability, as a key dimension of sustainable healthy diets, and the respective economic roles of animal- and plant-sourced foods need to be considered.

Trade policy reform, retail food prices and access to healthy diets worldwide

Recent use of least-cost diets as a measure of global food security revealed that over 3 billion people are unable to afford sufficient nutritious food for an active and healthy life, driving demand for policy changes to improve access and affordability. This study quantifies the role of imports in consumer prices, matching retail prices in 144 countries to imports by origin of the item or its main ingredient, resulting in a total of 13,846 pairs of a retail price and its import cost in 2017. We find that 55% of retail items had some active imports supplementing domestic production, and of those around 48% have nonzero tariffs whose average effective rate is around 6.7% of the imported commodity price. Over all countries for which data are available, the share of consumer prices for least-cost healthy diets that is attributable to tariffs and non-tariff measures averages 0.67% and 2.45% globally. The highest restrictions are on nutrient-rich vegetables, fruits and animal-sourced foods. Access to bulk commodities from diverse origins is essential for food and nutrition security, providing a greater diversity of foods and food ingredients at lower and more stable prices than can be grown at any one location. On average over all food products that are imported, 83% of the retail price is domestic value added after arrival. We conclude that food imports are best understood as inputs to the domestic production and distribution of retail items, with consumer prices and growth of the food sector dependent on the cost levels, infrastructure and institutions underlying each product’s entire value chain.

Nationally representative estimates of the cost of adequate diets, nutrient level drivers, and policy options for households in rural Malawi

A growing literature uses least-cost diets to evaluate how effectively a food system supports access to nutritious foods. We identify the cost of meeting nutrient requirements for whole households in rural Malawi from and the nutrient-level drivers thereof. From 2013 to 2017, we can identify a household least-cost diet only 60% of the time with an average cost of $2.32/person/day (2011 US$ PPP). We illustrate that larger households have more diverse nutrient needs and face a higher cost for 1000 calories of a sufficiently nutrient dense diet. Shadow price analysis shows riboflavin to be the costliest nutrient in the market. We use policy scenarios to understand what drives the infeasibility and high cost. Simulating the impact of selenium soil biofortification of maize results in a feasible diet 94% of the time at half the cost ($1.22/person/day on average) and eliminates the shadow price of copper. This is explained by insufficient selenium from sources low in copper such that under baseline conditions it is impossible to get enough selenium without too much copper. Even when feasible, to avoid copper, more higher cost foods enter the diet than would be otherwise needed to meet remaining nutrient requirements. Other value chain scenarios to increase the availability and lower the cost of nutrient-dense foods did not meaningfully change the diet cost results. Of direct relevance to Malawi, this study demonstrates more broadly how least-cost diet methods can be used to assess barriers to accessing an adequate diet and the potential impacts of policy options.

Muscle amino acid profiles of eleven species of aquacultured animals and their potential value in feed formulation

The complete quantitative essential amino acid (EAA) requirements of aquacultured animals are largely unknown except for a handful of species. This is problematic because formulation of least-cost diets for target animals demands precise knowledge of EAA requirements. One way of approximating EAA requirements is to use correlations between whole-body and/or muscle EAA profiles using essential to total EAA ratios (A/E ratios). This method requires a reference, quantified EAA requirement, usually lysine (Lys). To systematically evaluate the A/E ratio method, muscle AA profiles were measured in 10 species of teleost and whiteleg shrimp. In fish, Lys represented the dominant muscle EAA measured, ranging between 7.06 and 9.58 g/100 g protein, whereas, in shrimp, arginine (Arg) was quantified as the principal EAA. For non-EAA, glutamate (Glu) and glutamine were consistently the NEAA recorded at highest levels whereas, in shrimp, Glu + Gln was highest followed by aspartate (Asp) plus asparagine (Asn). Except for Arg, which was twice that of fish (P < 0.05), whiteleg shrimp expressed similar muscle A/E profiles. Strength of relationship between muscle EAA levels and known requirements were all strongly and positively correlated for non-salmonid species. When using Lys as the reference EAA there were few semblances between measured and estimated EAA requirements.

A Review and Meta-analysis of the Effects of Replacing Fishmeal with Insect Meals on Growth of Tilapias and Sharptooth Catfish

The high cost of fish feed has affected the culturing of tilapias and sharptooth catfish in Africa. However, Africa is well endowed with terrestrial insects that can potentially replace fishmeal in the diets of fish. In this paper, the nutritional index, availability, and cost of selected insect meals are compared. The SOLVER function in Excel was used to formulate least-cost diets of Musca domestica, Gryllotalpa africana, Schistocerca gregaria, Macrotermes natalensis, and Gonimbrasia belina. The crude protein levels of all the insects were above 50% and met the requirements of both fish species. The essential amino acid index (EAAI) was highest in M. domestica (3.2613). Except for M. natalensis, all the insect meals met the fat requirements for tilapias and sharptooth catfish. The most available insects were S. gregaria and M. domestica. Feed value was highest in fishmeal (15.62) followed by M. domestica (15.52). A meta-analysis of the effects of replacing fishmeal with insect meal on growth performance of tilapias and sharptooth catfish was also carried out. The effect summary for the specific growth rate was significant whereas the effect summary for the food conversion ratio was not significant. The relationship between fishmeal replacement levels and response ratio showed wide scatter. It was thus not possible to determine the optimum replacement level. Musca domestica is recommended in the replacement of fishmeal.

The application of nonlinear programming on ration formulation for dairy cattle

The objective of this study was to compare the application of iterative linear programming (iteLP), sequential quadratic programming (SQP), and mixed-integer nonlinear programming-based deterministic global optimization (MINLP_DGO) on ration formulation for dairy cattle based on Nutrient Requirements of Dairy Cattle (NRC, 2001). Least-cost diets were formulated for lactating cows, dry cows, and heifers. Nutrient requirements including energy, protein, and minerals, along with other limitations on dry matter intake, neutral detergent fiber, and fat were considered as constraints. Five hundred simulations were conducted, with each simulation randomly selecting 3 roughages and 5 concentrates from the feed table in NRC (2001) as the feed resource for each of 3 animal groups. Among the 500 simulations for lactating cows, 57, 45, and 21 simulations did not yield a feasible solution when using iteLP, SQP, and MINLP_DGO, respectively. All the simulations for dry cows and heifers were feasible when using SQP and MINLP_DGO, but 49 and 11 infeasible simulations occurred when using iteLP for dry cows and heifers, respectively. The average ration costs per animal per day of the feasible solutions obtained by iteLP, SQP, and MINLP_DGO were $4.78 (±0.71), $4.45 (±0.65), and $4.44 (±0.65) for lactating cows; $2.39 (±0.52), $1.48 (±0.26), and $1.48 (±0.26) for dry cows; and $0.98 (±0.72), $0.97 (±0.15), and $0.91 (±0.14) for heifers, respectively. The average computation time of iteLP, SQP, and MINLP_DGO were 0.59 (±1.87) s, 1.15 (±0.62) s, and 58.69 (±68.45) s for lactating cows; 0.041 (±0.070) s, 0.76 (±0.37) s, and 14.84 (±39.09) s for dry cows; and 1.60 (±2.90) s, 0.51 (±0.19) s, and 16.45 (±45.56) s for heifers, respectively. In conclusion, iteLP had limited capability of formulating least-cost diets when nonlinearity existed in the constraints. Both SQP and MINLP_DGO handled the nonlinear constraints well, with SQP being faster, whereas MINLP_DGO was able to return a feasible solution under some situations where SQP could not.

Global variation in the cost of a nutrient-adequate diet by population group: an observational study

SummaryBackgroundNutrient deficiencies limit human development and could be caused by the high cost of locally available foods needed to meet nutrient requirements. We aimed to identify the populations whose nutrient needs are most difficult to meet with existing global food systems.MethodsIn this observational study, we used the International Comparison Program 2017 collection of global food prices to measure cost per day and cost per calorie of meeting nutrient needs, based on least-cost diets within upper and lower bounds for energy and 20 nutrients for healthy populations across 20 demographic groups in 172 countries. We then analysed the composition of these least-cost diets by food groups to estimate how the affordability of foods for meeting nutrient needs varied by age, sex, and reproductive status.FindingsIn 2017, the global median of diet costs per day was US$2·32 (IQR 1·95–2·76), with cost highest for adolescent boys aged 14–18 years at $2·72 (2·31–3·15). For females, median cost was highest for adolescents aged 14–18 years during pregnancy and lactation at $2·64 (2·29–3·15), exceeding the cost for adult men aged 19–30 years. The global median of diet cost per 1000 kcal was $0·94 (IQR 0·80–1·12), and was higher for females throughout the life course than for males, peaking for adolescent girls aged 9–13 years ($1·17 [95% CI 1·15–1·19]) and women older than 70 years ($1·18 [1·17–1·19]). Diet costs were most sensitive to requirements for calcium, iron, zinc, and vitamins C and E, as well as the upper bounds on carbohydrates and sodium. Total diet costs per day did not vary significantly with national income; however, in high-income countries, the composition of least-cost diets included more animal-source foods, whereas in low-income countries, diets with more pulses, nuts and seeds, and fruits and vegetables provided the most affordable way to meet nutrient requirements.InterpretationDiets with adequate nutrients were unaffordable for many demographic groups, especially women and girls. These results could help to guide agriculture and food policy or transfer programmes to support populations at risk of inadequate intake.FundingThe Bill & Melinda Gates Foundation and UKAid.

Using Linear Programming to Determine the Role of Plant- and Animal-Sourced Foods in Least-Cost, Nutritionally Adequate Diets for Adults.

ABSTRACTBackgroundThe respective roles of plant- and animal-sourced foods in sustainable healthy diets for humans remain unclear. Nutritional quality and the monetary cost of diets are key criteria among others for sustainable food production.ObjectiveLinear programming (LP) was used to determine the composition of nutritionally adequate dietary patterns formulated at the lowest cost. The hypothesis tested was that animal-sourced foods would be included in least-cost diets due to their high density of particular essential nutrients.MethodsThe LP modeling work was based on eating patterns, retail food prices (2020), and the daily energy (11,150 kJ, 2665 kcal) and essential nutrient requirements (29 nutrients in total) of a reference adult in New Zealand (NZ). The LP modeling approach is publicly and freely available to readily illustrate the change in dietary profiles and daily diet cost, in the simulation of changes in energy and nutrient requirements, and price fluctuations within food groups.ResultsA nutrient-adequate, least-cost dietary pattern formulated from 883 foods, with a daily cost of NZ $3.23, included both animal- and plant-based foods. The nutrients found to be equally first-limiting were biotin, calcium, molybdenum, potassium, selenium, vitamin A, pantothenic acid, and vitamin C. When a dietary scenario with no animal-sourced foods was modeled, by increasing the retail prices of animal-sourced foods by 1.05 to 10.3 times, the daily cost of this plant-only dietary pattern was NZ $4.34. Additional nutrients, such as zinc, vitamin B-12, and vitamin D, were met at their daily minimum required levels.ConclusionsDietary patterns formulated at the lowest cost and meeting the daily minimum requirements for energy and essential nutrients for an adult in New Zealand relied on foods sourced from animals and plants.

356 Anomalies of Carbohydrate Digestion and Metabolism by Ruminants

Abstract Carbohydrate, derived either from plant cell walls (neutral detergent fiber; NDF) from fresh or conserved forages consumed by cows and growing cattle or from starch of grains and concentrates in commercial feedlot diets, provides most of the dietary energy for ruminant growth and production. The ruminants’ ability to harvest forage from remote, inaccessible locations, to scavenge energy from NDF of feeds and byproducts of grain largely indigestible by non-ruminants, and to employ non-protein N to form protein-rich, nutrient-dense foods for humans are key ecological advantages over non-ruminants. Outlined below are some topics needing research attention. First, feed composition tables invariably indicate that the digested energy (DE) of carbohydrates is 4.4 kilocalories per gram, yet the gross energy (GE) of purified carbohydrate polymers (starch; cellulose, glycogen) averages 4.18; monomers (hexoses, pentoses) average 3.74. Having DE exceed GE violates the first Law of Thermodynamics! Might this 5 percent discrepancy reflect underestimations of fecal lignin or of protein digestibility due to metabolic fecal N? Favoring feeds rich in carbohydrate, this discrepancy confounds formulation of least-cost diets. Secondly, site of digestion of carbohydrate alters its metabolizable energy (ME). Fermentation, though required to yield ME from NDF, generates methane and heat. In contrast, starches and sugars that escape ruminal fermentation, if digested in the small intestine, circumvent these losses increasing their relative ME. Unfortunately, when ruminally fermented, starch, either directly or via pH depression, reduces NDF fermentation; might ruminal NDF digestion be increased by feeding NDF plus buffer versus concentrate diet components asynchronously? Third, carbohydrate metabolites lost in urine (lactate, pentoses, hippuric acid) need further quantification. Finally, ruminally-formed metabolites (methylglyoxal, methane) adversely affect animal health and energetics. Ruminal modification (site- or time-targeted enzymes or inhibitors; altering the ruminal microbiome with pre- or probiotics, inoculants, nutraceuticals) should help enhance ruminant productivity and sustainability.

The Economics of Feeding Infants: Least-Cost Nutrient Adequate Diets From 6 to 23 Months of Age Using Breastmilk and Locally Available Foods in 31 Low-Income Countries

Abstract Objectives Meeting infant needs requires complementing breastmilk with the gradual introduction of solid foods after 6 months. Existing studies have limited evidence on the availability and cost of complementary foods needed during the 6–23 month window when millions of children experience irreversible harm from inadequate diets. Methods Using food prices from the World Bank on 374 items potentially used for infant foods and available for sale in 31 low-income countries, food composition data, and dietary reference intakes (DRIs), we compute least-cost diets for children between 6–23 months. We further used data for food yield and nutrient retention factors and introduced volume constraints. DRIs differ for children aged 6–8 months, 9–11 months, and 12–23 months. We used lower and upper bounds on 25 different nutrients plus fiber and sodium. Our primary specification (Scenario I) considers only total protein and fats, while a more restrictive Scenario II also considers 11 essential amino acids and fatty acids. Results The cost of complementary foods to replace breastmilk is $1–2/day at 6–8 months when small quantities of high-cost ingredients are needed, then declines to below $/1day at 9–11 months when lower-cost foods can be used before rising above $1/day again as children grow. Increased breastfeeding substitutes for complementary foods to a limited degree, as shown by the small decline in cost as breastmilk intake rises, and there is a clear threshold beyond which sufficiently nutrient-dense ingredients are very expensive or entirely unavailable. Average intake recommendation levels of breastmilk measured in low-income countries are close to that which makes complementary feeding least expensive, except in Scenario II for the youngest children. Conclusions We find that sufficient nutrients from complementary foods for infants from 6 to 23 months are not affordable for many households in these countries, implying a need for targeted assistance, especially in settings where household incomes are below the global poverty line of $1.90/person/day. Funding Sources This study was funded by the Bill &amp; Melinda Gates Foundation through the project Advancing Research on Nutrition and Agriculture (AReNA), Phase II (Investment ID: OPP1177007), jointly with the project Food Prices for Nutrition (INV-016158) funded by the Bill &amp; Melinda Gates Foundation and UKAid.

155 Opportunities and Challenges of Teaching Laboratory Content of a Swine Discipline-focused Course with Limited Swine Access

In spring semester, 2020, ANSC 412: Swine Production and Management (4 credits, lecture and laboratory) was offered in the Department of Animal Science at Texas A&M University following a period of nonappearance in the curriculum. Simultaneously, planned renovation of the campus swine teaching farm required depopulation of the existing herd. Hence, animal access for course laboratories was restricted for the 2020 spring and fall semesters. The objective is to present strategies to achieve effective laboratory learning objectives with limited livestock access. Average course enrollment in 2020 spring and fall semesters was 11 students of junior and senior standing. The course laboratory was held for two hours weekly for fifteen weeks. COVID-19 interruption of the spring semester, and arrival of pigs to the campus swine teaching farm in the fall semester, necessitated creation of ten equivalent laboratory sessions per semester. Example laboratory sessions include: panels with swine industry professionals, Pork Quality Assurance version 4.0 certification, virtual farm tours, evaluating genetic merit with National Swine Registry Swine Testing and Genetic Evaluation System EPD data and indexes, understanding least-cost diet formulation with diet formulation software, creating and implementing a Secure Pork Supply enhanced biosecurity plan for the campus swine farm, and multiple case study models of troubleshooting reproductive deficiencies with the US Pork Center of Excellence National Swine Reproduction Guide. Laboratory session execution facilitated achievement of TAMU Department of Animal Science programmatic learning outcomes, specifically: understanding animal breeding programs, animal husbandry, reproductive management, and nutrient conversion, and assessing business models and application of animal management strategies. In future semesters with unrestricted swine access for teaching, live-animal handling will be emphasized in the syllabus, yet preservation of effective classroom-based laboratories will persist. These methods have value for instructors operating without campus swine resources and those whose laboratory content has been impacted by COVID-19 disruption.

Nationally Representative Estimates of the Cost of Adequate Diets, Nutrient Level Drivers, and Policy Options for Households in Rural Malawi

A growing literature uses the cost of diets to evaluate how effectively a food system supports access to nutritious foods. We identify baseline levels, nutrient drivers, and potential policy-induced changes in the feasibility and cost of meeting nutrient requirements for whole households based on aggregate needs in rural Malawi from 2013 – 2017. We determine the availability and cost of a nutrient-adequate diet each month using the price and composition of foods available at the nearest market. We run more than 1 million models in total, one for every household in each month under baseline and eight policy simulation scenarios. We find diets containing adequate nutrients for whole families to be available 60% of the time from 2013–2017, and when available, costing an average $2.32/person/day (2011 US$ PPP). Further, we illustrate that as households grow in size and diversity of member types, the cost to acquire 1,000 calories of a sufficiently nutrient dense diet increases. Our policy simulations reveal that selenium is the nutrient hindering the availability of diets adequate and balanced in essential nutrients, but that riboflavin is the costliest nutrient to obtain in the market when a least-cost diet is available. We estimate selenium soil biofortification of maize would result in nearly universally available (94%) adequate diets at half the cost ($1.22/person/day on average). This far exceeds the potential impact of price or availability changes of foods dense in the costliest nutrients including eggs, milk, groundnuts, and dried fish. No other scenario improves availability or exceeds 1% average cost reduction. Of direct relevance to agriculture and nutrition policy in Malawi, this study demonstrates how the availability and cost of whole diets and the shad-ow prices of individual nutrients in retail markets can be used to identify barriers to accessing an adequate diet and estimate the potential impacts of policy options.

Software tools for practical application of human nutrient requirements in food-based social science research

This article focuses on the use of human nutrition requirements for applied social science research by non-nutrition experts. Our motivation is to provide the data and default nutrient requirements to calculate the Cost of Nutrient Adequacy (CoNA) least-cost diet meeting specified nutrient requirements. The final format of the resulting datafile is ready for use in the CoNA protocol. However, we expect this article and associated software tools to be generally useful to social science researchers interested in nutrition-related research questions and the potential implications of food systems’ changes for nutrition. We provide readily usable data files (Supplement 1) containing the Dietary Reference Intakes (DRIs) and guide non-nutrition experts through appropriate use to establish the nutrient needs and assess the adequacy of diets for populations and groups. We complement the DRIs with companion data files (Supplement 2) containing the WHO Child Growth Standards and WHO Growth References for School-Aged Children and Adolescents percentiles tables of anthropometric measures, extract the median heights and weights, and calculate median reference values for the age-sex groups consistent with the DRIs nutrient requirements. We provide calculations of energy requirements using the DRIs Estimated Energy Requirement (EER) equation and WHO growth references for all age-sex groups and physical activity levels. We also calculate the protein Estimated Average Requirement (EAR) per kilogram body weight according to the WHO growth references. For children under two, we provide nutrient needs required from food in Supplement 3. We provide Stata code and R syntax (Supplements 4 and 5) to compile the single data files into usable datasets for statistical analysis. Finally, we also provide data files (Supplement 6) with the recently proposed harmonized average values and upper levels and briefly discuss their potential application.

Cost and affordability of nutritious diets at retail prices: Evidence from 177 countries

Many policies and programs aim to bring nutritious diets within reach of the poor. This paper uses retail prices and nutrient composition for 671 foods and beverages to compute the daily cost of essential nutrients required for an active and healthy life in 177 countries around the world. We compare this minimum cost of nutrient adequacy with the subsistence cost of dietary energy and per-capita spending on all goods and services, to identify stylized facts about how diet cost and affordability relate to economic development and nutrition outcomes. On average, the most affordable nutrient adequate diet exceeds the cost of adequate energy by a factor of 2.66, costing US$1.35 per day to meet median requirements of healthy adult women in 2011. Affordability is lowest in Sub-Saharan Africa. The sensitivity of diet costs to each requirement reveals the high cost of staying within acceptable macronutrient ranges, particularly the upper limit for carbohydrates. Among micronutrients, total diet costs are most sensitive to requirements for calcium as well as vitamins A, C, E, B12, folate and riboflavin. On average, about 5% of dietary energy in the least-cost nutrient adequate diets is derived from animal source foods, with small quantities of meat and fish. Over 70% of all animal products in least-cost diets is eggs and dairy, but only in upper-middle and high-income countries. In lower income countries where egg and dairy prices are significantly higher, they are replaced by larger volumes of vegetal foods. When controlling for national income, diet costs are most significantly correlated with rural travel times and rural electrification. These data suggest opportunities for targeted policies and programs that reduce market prices and the cost of nutritious diets, while improving affordability through nutrition assistance, safety nets and higher earnings among low-income households.

Global Variation in the Cost of a Nutrient Adequate Diet by Population Group

Background: Nutrient deficiencies limit human development, and could be caused by the high cost of locally available foods needed to meet nutrient requirements. In this study, we identify the populations whose nutrient needs are most difficult to meet with existing global food systems. Methods: Using the most recent collection of global food prices (ICP 2017), we compute least-cost diets within upper and lower bounds for energy and 20 nutrients for healthy population across 20 demographic groups in 172 countries. Findings: Diet costs per day have a global median of $2.30 (IQR: 1.95-2.75) in 2017, and are highest for males 14-18 y/o at $2.85 [95%CI: 2.83, 2.88]. For females, cost per day is highest during pregnancy and lactation, exceeding cost for adult males 19-50 y/o. Energy-adjusted costs per 1,000 kcal have a global median of $0.94 (IQR: 0.79-1.12), and are higher for females throughout the life course, peaking for adolescent girls 9-13 y/o and women above 70 y/o at $1.17 [95% CI: 1.15, 1.19] and $1.18 [95% CI: 1.17, 1.19]. Meeting needs at least cost uses more animal-source foods in higher income countries, and more plant-source foods in lower income countries. Diet costs are most sensitive to requirements for calcium, iron, zinc and vitamins C and E, and upper bounds on carbohydrates and sodium. Interpretation: Diets with adequate nutrients are unaffordable for many demographic groups, especially women. Results can help guide agriculture and food policy or transfer programs to support populations at risk of inadequate intake. Funding Statement: UKAid and the Bill & Melinda Gates Foundation Declaration of Interests: The authors declare no competing interests.

Cost and Affordability of Nutritious Diets at Retail Prices: Evidence from 744 Foods in 159 Countries

Many policies and programs aim to bring nutritious diets within reach of the poor. This paper uses retail prices and nutrient composition for 671 foods and beverages to compute the daily cost of essential nutrients required for an active and healthy life in 177 countries around the world. We compare this minimum cost of nutrient adequacy with the subsistence cost of dietary energy and per-capita spending on all goods and services, to identify stylized facts about how cost and affordability relate to economic development and nutrition outcomes. On average, the most affordable nutrient adequate diet exceeds the cost of adequate energy by a factor of 2.66, costing US$1.35 per day to meet median requirements of healthy adult women in 2011. Affordability is lowest in Sub-Saharan Africa. The sensitivity of diet costs to each requirement reveals the high cost of staying within acceptable macronutrient ranges, particularly the upper limit for carbohydrates. Among micronutrients, total diet costs are most sensitive to requirements for calcium as well as vitamins A, C, E, B12, folate and riboflavin. On average, about 5% of dietary energy in the least-cost nutrient adequate diets is derived from animal source foods, with small quantities of meat and fish. Over 70% of all animal products in least-cost diets is eggs and dairy, but only in upper-middle and high-income countries. In lower income countries where egg and dairy prices are significantly higher, they are replaced by larger volumes of vegetal foods. When controlling for national income, diet costs are most significantly correlated with rural travel times and rural electrification. These data suggest opportunities for targeted policies and programs that reduce market prices and the cost of nutritious diets, while improving affordability through nutrition assistance, safety nets and higher earnings among low-income households.

Cost Advantage of Biofortified Maize for the Poultry Feed Industry and Its Implications for Value Chain Actors in Nepal

Feed constitutes a significant cost of poultry production. We assess the cost-reducing effects of using Quality Protein Maize (QPM) in the poultry feed industry in Nepal. We also assess market structure of the poultry feed industry. Key informant interviews and short surveys were conducted with actors in the feed industry and maize value chain. We formulated a least-cost diet for broilers and layers with regular maize and QPM using a linear programing model. The results indicate that a ton of feed produced using QPM instead of regular maize reduces feed cost by at least US$7.10 for broilers and at least US$4.71 for layers of different ages. With the cost saving, the feed industry can pay a maximum of 4% price premium for QPM over regular maize. A strong linkage between feed industry and maize value chain actors is required for the feed industry to benefit sustainably from the use of QPM.

The Cost of Nutritious Diets for Individuals and Households in Rural Malawi

Abstract Objectives The affordability of healthy diets is a key concern for policymakers and an active area of research. To the best of our knowledge, ours is the first study to examine the cost of nutritionally adequate diets for all population age and sex subgroups at subnational disaggregation over a 10-year monthly time series as well as to extend the least-cost diet framework from individuals to household units who consume shared meals. Methods We use household survey panel data matched with local food composition data, human nutrient requirements (EARs, ULs and AMDRs), and monthly market food prices. The food price data include a standardized list of 51 items comprising those foods accounting for the vast majority of household food spending, covering all food groups. Household data are from the Integrated Household Panel Survey (IHPS) 3-round panel (2010–2017). Using linear programming, we identify the combination of available foods and quantities that meet the specified nutrient requirements at the lowest total cost. Results Local markets can supply an adequate diet most of the time for some groups but much less often for breastfeeding women and young children, and not at al for children 6–36 months. Where possible, we find that the least-cost individual diet costs 32% of current per capita food spending. For whole households, the local market can meet aggregate nutrient needs 30% of the time. Where possible, it costs 1.8 times household food spending or all total expenditure. Food group analysis reveals households spend more on cereals, meat and roots/tubers, compared to the least-cost adequate diet, but may be under-spending on legumes, milk, fats, and vitamin A-rich fruits. Conclusions Finding a healthy diet in Malawi's local markets is not always possible for all types of individuals or families of varying composition. Children 6–36 months require immediate attention, including increasing access to complete complementary foods. Guiding households to make smart shifts in their food spending could improve diet quality but is insufficient alone given that adequate shared meals are unaffordable for most families. Year-round access to nutritious, affordable diets will require an increase in availability and lower cost of nutrient-dense foods and economic growth to raise incomes. Funding Sources Bill &amp; Melinda Gates Foundation, CANDASA project.

A goal programming approach for balancing diet costs and feed water use under different environmental conditions

Water is essential in livestock production systems. In typical dairy production systems, 90% of the total water used by a dairy farm is attributed to feed production. Theoretically, ration manipulation is a method to potentially reduce the irrigation water needed for feed crops without dramatically increasing diet costs. However, published quantitative studies on the relationship between feed production and water use that are integrated with linear programming models are scarce. The overall objective of this study was to develop an optimization framework that could achieve a balance between minimization of dietary costs and dietary irrigation water usage, and that could be used as a framework for future research and models for various livestock production systems. Weighted goal programming models were developed to minimize the dietary costs and irrigation water usage for a hypothetical cow under 8 different environmental scenarios. The environmental conditions used a 2 × 2 × 2 factorial design, including 2 atmospheric CO2 concentrations (400 and 550 ppm), 2 water years (dry and wet), and 2 irrigation methods (furrow and drip). A systematic weighting scheme was used to model the trade-off between minimizing diet cost and minimizing irrigation water use for feedstuffs. Each environmental condition generated a set of distinct diets, which each met the same nutrient requirements of the hypothetical cow but had a different water usage when the weighting scheme was changed from weighting minimum diet costs to minimum irrigation water usage. For water resource planning in areas of dairy production, this set of unique solutions provides the decision maker with different feeding options according to diet cost, water usage, and available feeds. As water was more constrained, dietary dry matter intake increased, concentrations of neutral detergent fiber, ether extract, and energy decreased, and the concentration of lignin increased because less nutritive but more water-saving feedstuffs were included in the diet. Mitigation costs of water usage were calculated from goal programming results and indicated that the potential value of water under water-limited conditions (e.g., in a drought region) was higher than that under water-sufficient conditions. However, a smaller increase in feed costs can initially significantly reduce water usage compared with that of a least-cost diet, which implies that the reduction of water usage through ration manipulation might be possible. This model serves as a framework for the study of irrigation water usage in dairy production and other livestock production systems and for decision-making processes involved in water resources planning in the broader area of animal production.

Cost and Affordability of the EAT- &lt;i&gt;Lancet&lt;/i&gt; Diet in 159 Countries

Background: The EAT-Lancet Commission drew on all available nutritional and environmental evidence to construct the first global benchmark diet capable of sustaining health and protecting the planet, but did not consider cost. We added data on food prices and calculated affordability to guide intervention towards improved diets around the world. Methods: We obtained retail price observations used by the World Bank to measure poverty, and identified the most affordable foods to meet EAT-Lancet targets. We compared total cost per day to each country's gross national income, computed the fraction of people for whom the most affordable EAT-Lancet diet exceeds household income, and measured affordability relative to a least-cost diet with only essential nutrients. Findings: We found prices for 744 items across 159 countries, revealing that the most affordable EAT-Lancet diets cost a global average of $2·89 per day (IQR: 2·41-3·16) in 2011, of which the largest share was the cost of fruits and vegetables (31·2 %), followed by legumes and nuts (18·7 %), meat, eggs & fish (15·2 %) and dairy (13·2 %). This diet costs a small fraction of available resources in high-income countries, but is not affordable for the world's poor. We estimated that the cost of an EATLancet diet exceeded household income for at least 1·56 billion people. The EAT-Lancet diet is also more expensive than the minimum cost of sufficient nutrients; on average, by a factor of 1·64 (IQR: 1·41-1·78). Interpretation: Current diets differ greatly from EAT-Lancet targets. Improving diets is affordable in many countries, but for many people would require some combination of higher income, nutrition assistance, and lower prices. Data and analysis on the cost of healthier foods is needed to inform both local interventions and systemic changes. Funding Statement: This study was funded by the Bill & Melinda Gates Foundation through the project Advancing Research on Nutrition and Agriculture (AReNA), Phase II (Investment ID: OPP1177007). The cost of nutrient adequacy component draws on data and methods from a related project funded by UKAid and the Bill & Melinda Gates Foundation, entitled Changing Access to Nutritious Diets in Africa and South Asia (CANDASA, OPP1182628). Declaration of Interests: The authors state: None. Ethics Approval Statement: Not required.