From diets to foods: using linear programming to formulate a nutritious, minimum-cost porridge mix for children aged 1 to 2 years

Nutritional Quality of Three Iron-Rich Porridges Blended with Moringa oleifera, Hibiscus sabdariffa, and Solanum aethiopicum to Combat Iron Deficiency Anemia among Children

Iron deficiency anemia has been a public health issue in children under five years of age in Cameroon. Very limited attempts have been carried out to develop an iron-rich food using local ingredients. The study aimed at developing functional porridges from local ingredients for iron-deficient children aged 6–23 months. Leaves of Moringa oleifera, Hibiscus sabdariffa, and Solanum aethiopicum were harvested as sources of iron, dried, ground into powder, and screened for their water and iron contents. Each vegetable powder was mixed with the other ingredients (dry whole milk, brown sugar, yellow maize flour, and refined soybean oil) to obtain three powdered porridges using linear programming (LP). Protein, lipid, carbohydrate, iron, energy, water, ash, crude fiber, and vitamin C contents, expressed in dry weight, were determined on powdered porridges. Powdered porridges were cooked in boiled water (ratio 2 : 7%w/w) for 5 min. Hedonic tests were conducted using cooked porridges with 50 untrained panelists. Leaf powders contained iron varying between 5.39 and 5.98 mg/100 g. LP models of the three porridges satisfied the nutritional requirements of children aged 6–23 months in terms of iron, lipid, protein, carbohydrate, and caloric daily intake. Protein, lipid, carbohydrate, iron, energy, water, ash, crude fiber, and vitamin C contents were, respectively, between 11.37 and 13.83 g/100g, 30.79 and 32.94 g/100g, 45.97 to 46.81 g/100g, 5.14 and 6.15 mg/100g, 509.93 and 517.48 kcal/100g, 6.42 to 7.62 g/100g, 2.20 and 2.88 g/100g, 1.65 and 2.44 g/100g, and 46.49 and 163.38 mg/100g. The cost of powdered porridges varied between 0.40 and 0.49 USD/100g. The sensory analysis showed that the moringa leaf-based porridge (82%) was the most appreciated followed by eggplant leaf-based porridge (80%) and folere leaf-based porridge (70%). Hence, these results showed that moringa, folere, and eggplant leaves can be used in functional foods to alleviate iron deficiency among children aged 6–23 months.

Optimization of Protein Quality of Plant-Based Foods Through Digitalized Product Development

With the increasing availability of plant-based protein products that should serve as alternatives to animal-based protein products, it is necessary to develop not only environmentally friendly but also nutritious foods. Especially the protein content and quality are of concern in these products. The algorithm of NutriOpt was developed using linear programming to support the development of food products with a balanced amino acid profile while considering digestibility. The current version contains a database with 84 plant protein sources from different food groups (legumes, cereals, nuts, seeds) and with different grades of purification (flours, concentrates, isolates) from which NutriOpt can create mixtures with high protein quality while complying with constraints such as protein content, number of ingredients, and weight of the mixture. The program was tested through different case studies based on commercial plant-based drinks. It was possible to obtain formulations with a Protein Digestibility Corrected Amino Acid Score (PDCAAS) over 100 with ingredients and quantities potentially suitable for plant-based analogs. Our model can help to develop the second generation of plant-based product alternatives that can really be used as an alternative on long-term consumption. Further, there is still a great potential of expansion of the program for example to use press cakes or even to model whole menus or diets in the future.

Formulation, Sensory Attributes and Nutrient Content of a Malted Sorghum-based Porridge: Potential for the Management of Moderate Acute Malnutrition among Infants and Young Children

Introduction:

Substituting corn in a fortified corn-soy blend (CSB+) with enzyme-active sorghum malt has the potential to be used as a suitable alternative supplementary porridge in the management of infants and young children (IYC) with moderate acute malnutrition (MAM) in Uganda.

Objective:

This study aimed to develop acceptable malted sorghum-based supplementary porridge (MSBP) that meets the energy and protein specifications for the management of IYC with MAM, using locally-available ingredients.

Methods:

MSBP formulations included the use of malted sorghum flour and extruded soy and corn flour. The ratio of the soy to corn ingredients was 3:7 (F617/F593), 1:1 (F892/F940), and 4:1 for CSB+, which is the standard care for the management of IYC with MAM in Uganda. The sorghum malt content for F617/F892 and F593/F940 was 25% and 30%, respectively. F617, F593, F892 and F940 met international specifications for a supplementary porridge. A comparison of the consumer acceptability scores and viscosity levels of these formulations was made, using analysis of variance.

Results and Discussion:

The scores for flavour, taste, mouth feel, sweetness and overall consumer acceptability differed among the formulations (p<0.05). F617 had a higher mean acceptability score than F593, F892 and F940 (p<0.05), as well as a higher energy and protein content than CSB+ (p<0.01). The energy density, protein density and viscosity of F617 were 1.6kcal/ g, 4g/100 kcal and 2809 cP, respectively, with a flour rate of 25%.

Conclusion:

Sorghum malt is suitable for the development of an acceptable supplementary porridge (MSBP). It meets the international energy and protein specifications for the management of IYC with MAM, and the F617 formulation meets these specifications.

Local foods can meet micronutrient needs for women in urban Burkina Faso, but only if rarely consumed micronutrient-dense foods are included in daily diets: A linear programming exercise

Women of reproductive age are at nutritional risk due to their need for nutrient-dense diets. Risk is further elevated in resource-poor environments. In one such environment, we evaluated feasibility of meeting micronutrient needs of women of reproductive age using local foods alone or using local foods and supplements, while minimizing cost. Based on dietary recall data from Ouagadougou, we used linear programming to identify the lowest cost options for meeting 10 micronutrient intake recommendations, while also meeting energy needs and following an acceptable macronutrient intake pattern. We modeled scenarios with maximum intake per food item constrained at the 75th percentile of reported intake and also with more liberal maxima based on recommended portions per day, with and without the addition of supplements. Some scenarios allowed only commonly consumed foods (reported on at least 10% of recall days). We modeled separately for pregnant, lactating, and nonpregnant, nonlactating women. With maxima constrained to the 75th percentile, all micronutrient needs could be met with local foods but only when several nutrient-dense but rarely consumed items were included in daily diets. When only commonly consumed foods were allowed, micronutrient needs could not be met without supplements. When larger amounts of common animal-source foods were allowed, all needs could be met for nonpregnant, nonlactating women but not for pregnant or lactating women, without supplements. We conclude that locally available foods could meet micronutrient needs but that to achieve this, strategies would be needed to increase consistent availability in markets, consistent economic access, and demand.

Fortifying pork liver mixture: Evaluation of protein quality and iron bioavailability – Part 2

ABSTRACT Objective To evaluate the protein quality and iron bioavailability of a fortifying mixture based on pork liver. Methods Determinations of protein efficiency ratio, net protein utilization, true digestibility and hemoglobin regeneration efficiency by depletion and repletion were performed. In the depletion phase, the animals (male Wistar rats) received an iron-free AIN–93G diet and in the repletion phase they received the following diets: standard AIN–93G diet, fortifying mixture and standard diet containing heptahydrated ferrous sulfate for comparison. Results For standard AIN–93G diet and fortifying mixture the results were 3.75 and 4.04 for protein efficiency ratio and 3.53 and 3.63 for net protein retention, showing that the presence of pork liver in the diet promoted an increase in protein efficiency ratio and net protein retention (not statistically significant). True digestibility results obtained with the fortifying mixture (97.16%) were higher than those obtained with the standard AIN–93G diet (casein), but without significant difference. The hemoglobin regeneration efficiency values obtained for standard AIN–93G diet, fortifying mixture and standard diet containing heptahydrated ferrous sulfate were 50.69, 31.96 and 29.96%, respectively, showing a statistically significant difference between the control (standard AIN–93G diet) and test (fortifying mixture and standard diet containing heptahydrated ferrous sulfate) samples, but not between the test samples. Conclusion The fortifying mixture showed a high protein efficiency ratio value of 4.04 and a high relative biological value (108%) and it can be added to soups, creams and meats in day-care centers for the prevention of iron-deficiency in children of school age.

Taking dietary habits into account: A computational method for modeling food choices that goes beyond price

Computational models have gained popularity as a predictive tool for assessing proposed policy changes affecting dietary choice. Specifically, they have been used for modeling dietary changes in response to economic interventions, such as price and income changes. Herein, we present a novel addition to this type of model by incorporating habitual behaviors that drive individuals to maintain or conform to prior eating patterns. We examine our method in a simulated case study of food choice behaviors of low-income adults in the US. We use data from several national datasets, including the National Health and Nutrition Examination Survey (NHANES), the US Bureau of Labor Statistics and the USDA, to parameterize our model and develop predictive capabilities in 1) quantifying the influence of prior diet preferences when food budgets are increased and 2) simulating the income elasticities of demand for four food categories. Food budgets can increase because of greater affordability (due to food aid and other nutritional assistance programs), or because of higher income. Our model predictions indicate that low-income adults consume unhealthy diets when they have highly constrained budgets, but that even after budget constraints are relaxed, these unhealthy eating behaviors are maintained. Specifically, diets in this population, before and after changes in food budgets, are characterized by relatively low consumption of fruits and vegetables and high consumption of fat. The model results for income elasticities also show almost no change in consumption of fruit and fat in response to changes in income, which is in agreement with data from the World Bank's International Comparison Program (ICP). Hence, the proposed method can be used in assessing the influences of habitual dietary patterns on the effectiveness of food policies.

Cost of the Diet: a method and software to calculate the lowest cost of meeting recommended intakes of energy and nutrients from local foods

BACKGROUND

When food is available, the main obstacle to access is usually economic: people may not be able to afford a nutritious diet, even if they know what foods to eat. The Cost of the Diet method and software was developed to apply linear programming to better understand the extent to which poverty may affect people's ability to meet their nutritional specifications. This paper describes the principles of the method; the mathematics underlying the linear programming; the parameters and assumptions on which the calculations are based; and then illustrates the output of the software using examples taken from assessments.

RESULTS

The software contains five databases: the energy and nutrient content of foods; the energy and nutrient specifications of individuals; predefined groups of individuals in typical households; the portion sizes of foods; and currency conversion factors. Data are collected during a market survey to calculate the average cost of foods per 100 g while focus group discussions are used to assess local dietary habits and preferences. These data are presented to a linear programming solver within the software which selects the least expensive combination of local foods for four standard diets that meet specifications for: energy only; energy and macronutrients; energy, macronutrients and micronutrients; and energy, macronutrients and micronutrients but with constraints on the amounts per meal that are consistent with typical dietary habits. Most parameters in the software can be modified by users to examine the potential impact of a wide range of theoretical interventions. The output summarises for each diet the costs, quantity and proportion of energy and nutrient specifications provided by all the foods selected for a given individual or household by day, week, season and year. When the cost is expressed as a percentage of income, the affordability of the diet can be estimated.

CONCLUSIONS

The Cost of the Diet method and software could be used to inform programme design and behaviour change communication in the fields of nutrition, food security, livelihoods and social protection as well as to influence policies and advocacy debates on the financial cost of meeting energy and nutrient specifications.

Complementary Feeding Diets Made of Local Foods Can Be Optimized, but Additional Interventions Will Be Needed to Meet Iron and Zinc Requirements in 6- to 23-Month-Old Children in Low- and Middle-Income Countries

Background:

The question whether diets composed of local foods can meet recommended nutrient intakes in children aged 6 to 23 months living in low- and middle-income countries is contested.

Objective:

To review evidence of studies evaluating whether (1) macro- and micronutrient requirements of children aged 6 to 23 months from low- and middle-income countries are met by the consumption of locally available foods (“observed intake”) and (2) nutrient requirements can be met when the use of local foods is optimized, using modeling techniques (“modeled intake”).

Methods:

Twenty-three articles were included after conducting a systematic literature search. To allow for comparisons between studies, findings of 15 observed intake studies were compared against their contribution to a standardized recommended nutrient intake from complementary foods. For studies with data on intake distribution, %< estimated average requirements were calculated.

Results:

Data from the observed intake studies indicate that children aged 6 to 23 months meet requirements of protein, while diets are inadequate in calcium, iron, and zinc. Also for energy, vitamin A, thiamin, riboflavin, niacin, folate, and vitamin C, children did not always fulfill their requirements. Very few studies reported on vitamin B6, B12, and magnesium, and no conclusions can be drawn for these nutrients. When diets are optimized using modeling techniques, most of these nutrient requirements can be met, with the exception of iron and zinc and in some settings calcium, folate, and B vitamins.

Conclusion:

Our findings suggest that optimizing the use of local foods in diets of children aged 6 to 23 months can improve nutrient intakes; however, additional cost-effective strategies are needed to ensure adequate intakes of iron and zinc.

Diet inequality prevails among consumers interested and knowledgeable in nutrition

Background

Previous studies have demonstrated a correlation between diet cost and adherence to nutritional recommendations among consumers in general. This has adverse effects on diet and health inequality. It could be hypothesized that consumers knowledgeable in nutrition escape this correlation.

Objective

Investigate whether the previously observed relationship between diet cost and nutritional quality prevails among consumers with an above-average interest in and knowledge of nutrition.

Design

Full open diet registrations of 330 students taking a basic university-level course in nutrition over a total of 780 days.

Results

The consumers with the highest daily average diet cost differ from the lowest cost quartile: The diets had higher micronutrient density, more fruits and vegetables, and lower energy density. The highest cost daily diet quartile had a significantly higher energy adjusted intake of the micronutrients that were on average consumed below the recommendation (vitamin D, folate, and iron for women). On the other hand, alcohol intake was significantly higher among the high diet cost group. The highest diet cost respondents consumed more fish, meat, coffee, and spreads, whereas the lowest diet cost respondents had a higher consumption of cereals, bread, jam, sausage, and milk.

Conclusions

Dietary differences prevail even in the above-average interested and knowledgeable group. The respondents did not use their higher level of knowledge to break this commonly observed relationship. This suggests that an increased minimum level of knowledge in nutrition may not by itself eliminate dietary inequality.

Has it become increasingly expensive to follow a nutritious diet? Insights from a new price index for nutritious diets in Sweden 1980-2012

Background

Health-related illnesses such as obesity and diabetes continue to increase, particularly in groups of low socioeconomic status. The increasing cost of nutritious food has been suggested as an explanation.

Objective

To construct a price index describing the cost of a diet adhering to nutritional recommendations for a rational and knowledgeable consumer and, furthermore, to investigate which nutrients have become more expensive to obtain over time.

Methods

Linear programming and goal programming were used to calculate two optimal and nutritious diets for each year in the interval under different assumptions. The first model describes the rational choice of a cost-minimizing consumer; the second, the choice of a consumer trying to deviate as little as possible from average consumption. Shadow price analysis was used to investigate how nutrients contribute to the diet cost.

Results

The cost of a diet adhering to nutritional recommendations has not increased more than general food prices in Sweden between 1980 and 2012. However, following nutrient recommendations increases the diet cost even for a rational consumer, particularly for vitamin D, iron, and selenium. The cost of adhering to the vitamin D recommendation has increased faster than the general food prices.

Conclusions

Not adhering to recommendations (especially those for vitamin D) offers an opportunity for consumers to lower the diet cost. However, the cost of nutritious diets has not increased more than the cost of food in general between 1980 and 2012 in Sweden.