Food composition tables in resource-poor settings: exploring current limitations and opportunities, with a focus on animal-source foods in sub-Saharan Africa

Development, validation, and application of a South African Dietary Polyphenol Data Quality Assessment Tool

There is a wealth of South African scientific literature studying and reporting on dietary polyphenols in research articles and academic literature. The evaluation of data quality is critical to ensure polyphenol data compiled from various scientific journals and academic texts are acceptable in terms of compilation standards. This study aimed to develop, validate, and apply a country specific South African dietary polyphenol data quality assessment tool (SADPDQAT). The evaluation tool considered nine evaluation categories with a maximum score of 5. For each literature source assessed, a quality score and confidence code was assigned. Validation analysis revealed generally consistent results between raters with an average percentage agreement of 65 %, no scores falling outside of Bland-Altman limits of agreement and a moderate internal consistency α = 0.533 which was improved to 0.616. Applying the tool to 383 scientific studies showed that most literature obtained a quality score between 70 and 79 % resulting in a confidence code of "B" (n = 166, 43 %) and a score between 60 and 69 % resulting in a confidence code of "C" (n = 125, 33 %). The SADPDQAT can be used to evaluate a variety of dietary polyphenol containing literature and aids in setting priorities for further research in this area.

Nutrient-Dense African Indigenous Vegetables and Grains in the FAO Food Composition Table for Western Africa (WAFCT) Identified Using Nutrient-Rich Food (NRF) Scores

Nutrient profiling (NP) models that assess nutrient density of foods can help remedy micronutrient deficiencies. We used NP methods to identify the most nutrient-rich foods in the 2019 FAO/INFOODS Western Africa Food Composition Table (WAFCT). The WAFCT had complete data for 909 foods. Three versions of the well-established Nutrient-Rich Food (NRF) model were used: (1) the original NRF9.3 based on 9 micronutrients (protein, fiber, calcium, iron, potassium, magnesium, vitamin A, vitamin C, and vitamin D); (2) a new NRF6.3 based on 6 priority micronutrients (iron, zinc, calcium, folate, vitamin A, vitamin B12); and (3) NRF 15.3, based on 15 nutrients to encourage (NRF6.3 nutrients + vitamin D, vitamin E, vitamin C, vitamin B1, vitamin B2, vitamin B3, vitamin B6, copper, and magnesium). Data analyses used one-way ANOVAs and independent t-tests, with significance at α = 0.05. Animal-source foods were rated higher by NRF6.3 priority micronutrient and NRF15.3 NP models than by the NRF9.3 model. African indigenous vegetables had higher protein content and higher nutrient density compared to non-indigenous vegetables, and African indigenous grains had higher nutrient density compared to non-indigenous grains. Though animal-source foods received some of the highest scores, NP models adapted to the West African context showed that African indigenous vegetables and grains were also nutrient rich. Indigenous foods could be important sources of priority micronutrients for the region.

Measuring dietary intake in low-and middle-income countries: a systematic review of the methods and tools for estimating fish and seafood intake

CONTEXT

Fish and seafood consumption makes an important but often under-recognized contribution to dietary patterns and nutrition, particularly in low- and middle-income countries (LMICs). Therefore, valid, and reliable dietary assessment tools (DATs) and methods to measure seafood consumption in resource-poor settings are needed.

OBJECTIVE

To review the available DATs that have been used to measure fish and seafood consumption in LMICs and to assess their quality.

DATA SOURCES

A systematic search of the electronic databases Scopus, Embase, and Medline was conducted, identifying 1541 initial articles, of which 122 eligible full-text articles were reviewed.

DATA EXTRACTION

Data extraction focused on the purpose of dietary assessment, setting, target population group, DAT type, administration mode, type of fish and seafood assessed, specific measure of food intake, use of a portion-size-estimation aid, and details of validity, reliability, and pilot testing of the DATs.

DATA ANALYSIS

The most common DATs used were food frequency questionnaires (n = 80; 58%), of which 36 (25%) were semi-quantitative. The majority of tools (n = 107; 78%) included measurement of consumption frequency; only 41 studies (30%) measured frequency, quantity, and type of seafood consumed. Only 41 DATs (30%) solely focused on fish or seafood intake. Most DATs were interviewer administered (n = 80; 58%), 23 (16%) mentioned the use of a portion-size-estimation aid, and validity was tested for only 13% of DATs (n = 18).

CONCLUSION

This systematic review reveals a lack of sufficient detail in the use of standard DATs to fully capture the contribution of fish and seafood to diets in LMICs. Consequently, the need to develop or adapt existing DATs to capture frequency, quantity, and type of fish and seafood intake with consideration of cultural eating practices has been highlighted. This is essential for informing appropriate interventions to leverage the nutritional benefits of seafood consumption in LMICs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021253607.

Contribution of Village Chickens in Sustainable and Healthy Food Systems for Children along a Rural-Urban Gradient: A Systematic Review

Achieving sustainable and healthy food systems in support of human and planetary health is a global challenge. We systematically reviewed papers (n = 2322) showing how village chicken products (meat, eggs, and offal) contribute to sustainable and healthy food systems for children along a rural-urban gradient. A total of 72 articles, representing all different sections covered in this review, were finally included. Production of village chickens contributed positively on livestock-derived food consumption by children. Households who owned chickens were likely to move from medium to high dietary diversity. Children from households that owned chickens had lower odds of anemia (1.07) and higher height-for-age (HAZ) and weight-for-age (WAZ) scores. Egg intervention increased HAZ and WAZ for children by 0.63 [95% confidence interval (CI), 0.38-0.88] and 0.61 [95% CI, 0.45-0.77], respectively. Village chicken ownership had positive effect on children's poultry meat and egg consumption. Per capita consumption of chicken by girls and boys combined was 38.2 g/day, where girls had 36.9 g/day and boys had 39.4 g/day. Children from households that owned chickens consumed eggs 2.8 more times per week compared to children from households without chickens. Moving along a rural-urban gradient, village chicken production was less common. Improved production and quality of village chicken products, and policies supporting optimal maternal and child intake these products are required.

Social and economic factors influencing intrahousehold food allocation and egg consumption of children in Kaduna State, Nigeria

Adequate intake of high-quality nutritious foods during infancy and early childhood is critical to achieving optimal growth, cognitive and behavioural development, and economic productivity later in life. Integrating high-quality and nutrient-dense animal source foods (ASFs), a major source of protein and micronutrients, into children's diets is increasingly considered essential to reducing the global burden of malnutrition in low- and middle-income countries. While eggs are an ASF that shows promise for mitigating child undernutrition, interventions promoting egg consumption among children have had mixed results in improving egg intake and child growth outcomes. As part of an evaluation of a demand creation campaign promoting egg consumption, qualitative research was carried out in September 2019 to assess sociocultural and household factors affecting egg intake among young children living in Kaduna State, Nigeria, where a thriving egg industry and childhood stunting rates of 50% exist. Methods included freelisting exercises (11), key informant interviews (11), in-depth interviews (25) and FGDs (4). Results illuminated cultural rules that restrict egg consumption among children living in low-income households. These rules and norms reflect social and economic valuations that foster male dominance in household decision-making and guide food purchasing and intrahousehold food allocation that allow men to consume eggs more regularly. Study results highlight sociocultural considerations when selecting food interventions to address child malnutrition in low-income contexts. Interventions encouraging increased consumption of ASFs, and specifically eggs in young children, should be informed by formative research to understand sociocultural norms and beliefs guiding egg consumption.

Statistical Methods for the Analysis of Food Composition Databases: A Review

Evidence-based knowledge of the relationship between foods and nutrients is needed to inform dietary-based guidelines and policy. Proper and tailored statistical methods to analyse food composition databases (FCDBs) could assist in this regard. This review aims to collate the existing literature that used any statistical method to analyse FCDBs, to identify key trends and research gaps. The search strategy yielded 4238 references from electronic databases of which 24 fulfilled our inclusion criteria. Information on the objectives, statistical methods, and results was extracted. Statistical methods were mostly applied to group similar food items (37.5%). Other aims and objectives included determining associations between the nutrient content and known food characteristics (25.0%), determining nutrient co-occurrence (20.8%), evaluating nutrient changes over time (16.7%), and addressing the accuracy and completeness of databases (16.7%). Standard statistical tests (33.3%) were the most utilised followed by clustering (29.1%), other methods (16.7%), regression methods (12.5%), and dimension reduction techniques (8.3%). Nutrient data has unique characteristics such as correlated components, natural groupings, and a compositional nature. Statistical methods used for analysis need to account for this data structure. Our summary of the literature provides a reference for researchers looking to expand into this area.

Wildmeat consumption and child health in Amazonia

Consuming wildmeat may protect against iron-deficiency anemia, a serious public health problem globally. Contributing to debates on the linkages between wildmeat and the health of forest-proximate people, we investigate whether wildmeat consumption is associated with hemoglobin concentration in rural and urban children (< 5 years old) in central Brazilian Amazonia. Because dietary practices mediate the potential nutritional benefits of wildmeat, we also examined whether its introduction into children's diets is influenced by rural/urban location or household socio-economic characteristics. Sampling 610 children, we found that wildmeat consumption is associated with higher hemoglobin concentration among the rural children most vulnerable to poverty, but not in the least vulnerable rural, or urban children. Rural caregivers share wildmeat with children earlier-in-life than urban caregivers, potentially because of cultural differences, lower access to domesticated meat, and higher wildmeat consumption by rural households (four times the urban average). If wildmeat becomes unavailable through stricter regulations or over-harvesting, we predict a ~ 10% increased prevalence of anemia among extremely poor rural children. This modest protective effect indicates that ensuring wildmeat access is, alone, insufficient to control anemia. Sustainable wildlife management could enhance the nutritional benefits of wildlife for vulnerable Amazonians, but reducing multidimensional poverty and improving access to quality healthcare are paramount.

Review of dietary assessment studies conducted among Khmer populations living in Cambodia

Background

Despite economic growth, Cambodia continues to have high rates of malnutrition, anaemia and nutrition‐related deficiencies. Government policies promote nutrition strategies, although dietary intake data is limited. A detailed synthesis of existing intake data is needed to inform nutrition policy and practice change. This review aims to characterise and assess quality of dietary assessment methods and outcomes from individual‐level ‘whole diet’ studies of Khmer people living in Cambodia.

Methods

Searches were conducted using PRISMA‐ScR guidelines. Included papers reported dietary intake at an individual level for ‘whole diet’. Studies using secondary data or lacking dietary assessment details were excluded. Extracted data included dietary assessment features, nutrient/food group intakes and database.

Results

Nineteen publications (15 studies) were included, with nine carried out among children under 5 years and six among women. Eleven studies reported intake by food groups and four by nutrients, prominently energy, protein, vitamin A, iron, calcium and zinc. Inconsistent intakes, food groupings and reporting of study characteristics limited data synthesis. All but one study used 24‐h recalls. Trained local fieldworkers used traditional interview‐administered data collection and varied portion estimation tools. Food composition databases for analysis were not tailored to the Cambodian diet. Overall quality was rated as ‘good’.

Conclusions

We recommend the development of a best‐practice protocol for conducting dietary assessment, a Cambodia‐specific food composition database and a competent trained workforce of nutrition professionals, with global support of expertise and funding for future dietary assessment studies conducted in Cambodia.

Fifteen studies with highly variable intake data included in the review.

The food composition databases used were not specific to Cambodian diet.

Minimum reporting standards and best practice protocols recommended, including in‐country nutrition training.

Lack of whole population dietary intake data indicates the need for a national survey.

A review of micronutrient deficiencies and analysis of maize contribution to nutrient requirements of women and children in Eastern and Southern Africa

This paper reviews and analyses the importance of maize as staple food in Eastern and Southern Africa (E&SA) and contributes in understanding the nexus between maize nutritional composition and prevalence of micronutrient deficiencies (MNDs) in these regions. MNDs remain a major public health concern particularly for women and children, with calcium, iodine, iron, selenium, zinc, folate and vitamin A deficiencies being the most common. Estimates of their prevalence are among the highest in E&SA: iron-deficient anemia affected 26 to 31% of women of reproductive age, and deficiencies up to 53%, 36%, 66%, 75% and 62% for vitamin A, iodine, zinc, calcium and selenium, respectively, were measured in populations of these regions. Besides, these two regions show the highest worldwide maize per capita consumption (g/person/day) as main staple, with 157 in Eastern Africa and 267 in Southern Africa, including up to 444 in Lesotho. The analysis of food composition tables from these regions showed that 100 g of maize foods consumed by these populations could to some extent, contribute in satisfying dietary reference intakes (DRIs) of children and women in energy, proteins, carbohydrates, magnesium, zinc, vitamins B1 and B6. However, it provides very low supply of fats, calcium, sodium, selenium, vitamins C, A and E. The high occurrence of MNDs and considerable nutritional potential of maize consumed in E&SA can be explained by loss of nutrients due to processing practices, low food diversification and reduced nutrients bioavailability. Success cases of the main strategies to tackle the issue of MNDs in these regions by improving maize nutritional quality are discussed in this paper. Maize fortification was shown to improve nutrition and health outcomes of population. Increasing dietary diversity by complementing maize with other foods has improved nutrition through integration of micronutrient-rich foods in the diet. Mostly, biofortification has successfully contributed in reducing vitamin A and zinc deficiencies in rural communities more than nutrient supplementation, fortification and dietary diversity.

Source apportionment of micronutrients in the diets of Kilimanjaro,Tanzania and Counties of Western Kenya

Soil, water and food supply composition data have been combined to primarily estimate micronutrient intakes and subsequent risk of deficiencies in each of the regions studied by generating new data to supplement and update existing food balance sheets. These data capture environmental influences, such as soil chemistry and the drinking water sources to provide spatially resolved crop and drinking water composition data, where combined information is currently limited, to better inform intervention strategies to target micronutrient deficiencies. Approximately 1500 crop samples were analysed, representing 86 food items across 50 sites in Tanzania in 2013 and >230 sites in Western Kenya between 2014 and 2018. Samples were analysed by ICP-MS for 58 elements, with this paper focussing on calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), iodine (I), zinc (Zn) and molybdenum (Mo). In general, micronutrient supply from food groups was higher from Kilimanjaro,Tanzania than Counties in Western Kenya, albeit from a smaller sample. For both countries leafy vegetable and vegetable food groups consistently contained higher median micronutrient concentrations compared to other plant based food groups. Overall, calculated deficiency rates were <1% for Cu and Mo and close to or >90% for Ca, Zn and I in both countries. For Mg, a slightly lower risk of deficiency was calculated for Tanzania at 0 to 1% across simplified soil classifications and for female/males, compared to 3 to 20% for Kenya. A significant difference was observed for Se, where a 3 to 28% risk of deficiency was calculated for Tanzania compared to 93 to 100% in Kenya. Overall, 11 soil predictor variables, including pH and organic matter accounted for a small proportion of the variance in the elemental concentration of food. Tanzanian drinking water presented several opportunities for delivering greater than 10% of the estimated average requirement (EAR) for micronutrients. For example, 1 to 56% of the EAR for I and up to 10% for Se or 37% for Zn could be contributed via drinking water.

Prevalence of Gastrointestinal Parasites in Local and Exotic Breeds of Chickens in Pankrono-Kumasi, Ghana

The world's poultry population is on the ascendency as a result of the high demand for poultry product by consumers. In Africa, poultry meat is estimated to represent almost 25% of all meat, whereas in some areas it covers 100% of the animal protein available. The high demand for poultry products has led to an increase in poultry production in almost all African countries including Ghana, with the domestic chicken being the most kept. The sector has been reported to have recorded a drop in production, partly due to infection of birds by diseases, causing organisms including parasites. The study conducted was to investigate the prevalence of gastrointestinal parasites in local and exotic breeds of chickens in Pankrono–Kumasi in the Ashanti Region of Ghana. Two hundred (200) cloacae of slaughtered birds were collected from slaughtering units in the study area and the faecal samples were examined for the eggs/cysts of gastrointestinal parasites using the simple flotation technique and microscopy. Nematodes and cestodes were recovered in 131 (65.5%) of the samples examined with Ascaridia galli recorded as the most prevalent. Some of the nematodes include Ascaridia galli 65 (32.5%), Heterakis gallinarum 38 (19.0%), and Capillaria spp. 29 (14.5%). Some cestodes were Raillietina spp. 19(9.5%) and Choanotaenia infundibulum 5 (2.5%) with Prosthogonimus spp. 3 (1.5%) being the only trematode recovered. The local breeds recorded a percentage prevalence of 76.0%, making them the most susceptible breed to gastrointestinal parasites. The results obtained attest to the reason behind the reduction in poultry production. It is therefore recommended that farmers are educated on farm managerial practices that will reduce the risk of infection and help increase production to meet the demand of consumers.

Measures and metrics of sustainable diets with a focus on milk, yogurt, and dairy products

The 4 domains of sustainable diets are nutrition, economics, society, and the environment. To be sustainable, foods and food patterns need to be nutrient-rich, affordable, culturally acceptable, and sparing of natural resources and the environment. Each sustainability domain has its own measures and metrics. Nutrient density of foods has been assessed through nutrient profiling models, such as the Nutrient-Rich Foods family of scores. The Food Affordability Index, applied to different food groups, has measured both calories and nutrients per penny (kcal/$). Cultural acceptance measures have been based on relative food consumption frequencies across population groups. Environmental impact of individual foods and composite food patterns has been measured in terms of land, water, and energy use. Greenhouse gas emissions assess the carbon footprint of agricultural food production, processing, and retail. Based on multiple sustainability metrics, milk, yogurt, and other dairy products can be described as nutrient-rich, affordable, acceptable, and appealing. The environmental impact of dairy farming needs to be weighed against the high nutrient density of milk, yogurt, and cheese as compared with some plant-based alternatives.

Trends in energy and nutrient supply in Ethiopia: a perspective from FAO food balance sheets

BACKGROUND

Ethiopia is the second-most populous country in Africa. Although most people still live in rural areas, the urban population is increasing. Generally, urbanisation is associated with a nutrition transition and an increase in risk factors for non-communicable diseases (NCDs). The objective of this study was to determine how the nutritional composition of the Ethiopian food supply has changed over the last 50 years and whether there is evidence of a nutrition transition.

METHODS

Food balance sheets for Ethiopia from 1961 to 2011 were downloaded from the FAOSTAT database and daily per capita supply for 17 commodity groupings was calculated. After appropriate coding, per capita energy and nutrient supplies were determined.

RESULTS

Per capita energy supply was 1710 kcal/d in 1961, fell to 1403 kcal/d by 1973, and increased to 2111 kcal/d in 2011. Carbohydrate was by far the greatest energy source throughout the period, ranging from 72% of energy in 1968 to 79% in 1998; however, this was mostly provided by complex carbohydrates as the contribution of sugars to energy only varied between 4.7% in 1994 and 6.7% in 2011. Energy from fat was low, ranging from 14% of energy in 1970 to 10% in 1998. Energy from protein ranged from 14% in 1962 to 11% in 1994. Per capita supplies of calcium, vitamin A, C, D, folate and other B-vitamins were insufficient and there was a low supply of animal foods.

CONCLUSIONS

The Ethiopian food supply is still remarkably high in complex carbohydrates and low in sugars, fat, protein, and micronutrients. There is little evidence yet of changes that are usually associated with a nutrition transition.

Family poultry: Multiple roles, systems, challenges, and options for sustainable contributions to household nutrition security through a planetary health lens

Achieving sustainable production of eggs by family poultry production systems that meet both environmental health and welfare standards is a complex endeavour. Humans have been raising different species of poultry for thousands of years across many different agroecological zones. The Food and Agriculture Organization of the United Nations has identified four different family poultry production systems: small extensive, extensive, semi‐intensive, and intensive. Each of these systems varies in terms of inputs, outputs, gender dimensions, poultry health and welfare, and environmental impacts. This paper addresses key issues associated with the production of family poultry eggs in support of both improved maternal and child nutrition and sustainable, nutrition‐sensitive agricultural practices. It provides an overview of the history of poultry raising; characteristics of the different family poultry production systems; challenges and solutions to poultry production in low‐ and middle‐income countries; poultry husbandry (including breeds, nutrition, and shelter); infectious disease prevention and control in line with national and international animal health regulations; and food safety (microbial pathogens, toxins, and egg storage). To ensure that bird, human, and environmental health can flourish, it is essential for interdisciplinary research and development teams to work in collaboration with communities to ensure the long‐term environmental and economic sustainability of family poultry production enterprises that are a good fit with local circumstances.

Importance and use of reliable food composition data generation by nutrition/dietetic professionals towards solving Africa's nutrition problem: constraints and the role of FAO/INFOODS/AFROFOODS and other stakeholders in future initiatives

Despite the rich biodiversity of the African continent and the tremendous progress so far made in food production, Africa is still struggling with the problems of food insecurity, hunger and malnutrition. To combat these problems, the production and consumption of nutritious and safe foods need to be promoted. This cannot be achieved without reliable data on the quantity and quality of nutrients and other components provided through these foods. Food composition data (FCD) are compiled as food composition tables (FCT) or food composition databases (FCDB). These are subsequently used for a variety of purposes, ranging from clinical practice, research, public health/education, food industry to planning and policy, as well as nutrition monitoring and surveillance. To perform these functions effectively, the importance of reliable FCT/FCDB cannot be overemphasised. Poor quality FCT/FCDB have serious consequences on the health of the population, and provide skew evidence towards developing nutrition and health-related policies. The present paper reviews different methods to generate FCT/FCDB, their importance and use in assisting nutrition/dietetic professionals in solving Africa's nutrition problems; current status of FCT/FCDB generation, compilation and dissemination in Africa, constraint to their use by professionals and the role of FAO/INFOODS/AFROFOODS and other stakeholders towards improvement and future initiatives. The information provided will create awareness on the need for up-to-date and high-quality FCT/FCDB and facilitate the identification of data gaps and prioritisation of future efforts in FCD generation, compilation and dissemination in Africa and subsequent strategies for the alleviation of the food and nutrition problems in Africa.

The Failure to Measure Dietary Intake Engendered a Fictional Discourse on Diet-Disease Relations

Controversies regarding the putative health effects of dietary sugar, salt, fat, and cholesterol are not driven by legitimate differences in scientific inference from valid evidence, but by a fictional discourse on diet-disease relations driven by decades of deeply flawed and demonstrably misleading epidemiologic research. Over the past 60 years, epidemiologists published tens of thousands of reports asserting that dietary intake was a major contributing factor to chronic non-communicable diseases despite the fact that epidemiologic methods do not measure dietary intake. In lieu of measuring actual dietary intake, epidemiologists collected millions of unverified verbal and textual reports of memories of perceptions of dietary intake. Given that actual dietary intake and reported memories of perceptions of intake are not in the same ontological category, epidemiologists committed the logical fallacy of "Misplaced Concreteness." This error was exacerbated when the anecdotal (self-reported) data were impermissibly transformed (i.e., pseudo-quantified) into proxy-estimates of nutrient and caloric consumption via the assignment of "reference" values from databases of questionable validity and comprehensiveness. These errors were further compounded when statistical analyses of diet-disease relations were performed using the pseudo-quantified anecdotal data. These fatal measurement, analytic, and inferential flaws were obscured when epidemiologists failed to cite decades of research demonstrating that the proxy-estimates they created were often physiologically implausible (i.e., meaningless) and had no verifiable quantitative relation to the actual nutrient or caloric consumption of participants. In this critical analysis, we present substantial evidence to support our contention that current controversies and public confusion regarding diet-disease relations were generated by tens of thousands of deeply flawed, demonstrably misleading, and pseudoscientific epidemiologic reports. We challenge the field of nutrition to regain lost credibility by acknowledging the empirical and theoretical refutations of their memory-based methods and ensure that rigorous (objective) scientific methods are used to study the role of diet in chronic disease.

Controversy and debate: Memory-Based Methods Paper 1: the fatal flaws of food frequency questionnaires and other memory-based dietary assessment methods

There is an escalating debate over the value and validity of self-reported dietary intake as estimated by Food Frequency Questionnaires and other forms of memory-based dietary assessment methods. Proponents argue that despite limitations, memory-based methods provide valid and valuable information about consumed foods and beverages and therefore can be used to assess diet-disease relations. In fact, over the past 60 years, thousands of memory-based dietary research reports were used to inform public policy and establish the Dietary Guidelines for Americans. Yet, despite this impressive history, our position is that memory-based dietary assessment methods are invalid and inadmissible for scientific research and therefore cannot be used in evidence-based policy making. Herein, we present the empirical evidence and theoretic and philosophic perspectives that render data derived from memory-based methods both fatally flawed and pseudoscientific. First, the use of memory-based methods is founded upon two inter-related logical fallacies: a category error and reification. Second, human memory and recall are not valid instruments for scientific data collection. Third, in standard epidemiologic contexts, the measurement errors associated with self-reported data are nonfalsifiable because there is no way to ascertain if the reported foods and beverages match the respondent's actual consumption. Fourth, the assignment of nutrient and energy values to self-reported intake (i.e., the pseudoquantification of anecdotal data) is impermissible and violates the foundational tenets of measurement theory. Fifth, the proxy estimates created via pseudoquantification are often physiologically implausible and have little relation to actual nutrient and energy consumption. Finally, investigators engendered a fictional discourse on the health effects of dietary sugar, salt, fat and cholesterol when they failed to cite contrary evidence or address decades of research demonstrating the fatal measurement, analytic, and inferential flaws of memory-based dietary assessment methods.

The Gut Microbiota, Food Science, and Human Nutrition: A Timely Marriage

Analytic advances are enabling more precise definitions of the molecular composition of key food staples incorporated into contemporary diets and how the nutrient landscapes of these staples vary as a function of cultivar and food processing methods. This knowledge, combined with insights about the interrelationship between consumer microbiota configurations and biotransformation of food ingredients, should have a number of effects on agriculture, food production, and strategies for improving the nutritional value of foods and health status. These effects include decision-making about which cultivars of current or future food staples to incorporate into existing and future food systems, and which components of waste streams from current or future food manufacturing processes have nutritional value that is worth capturing. They can also guide which technologies should be applied, or need to be developed, to produce foods that support efficient microbial biotransformation of their ingredients into metabolic products that sustain health.

Global Dietary Surveillance: Data Gaps and Challenges

BACKGROUND

Detailed information on global individual-level consumption patterns is imperative for informed policy making. However, such data are dispersed and incomplete.

OBJECTIVE

To review and discuss the methodologies, observed data availability, challenges, and opportunities pertaining to global dietary surveillance.

METHODS

This investigation provides an extensive review of global dietary assessment methodologies and challenges, including at the survey level, the dietary collection and assessment level, and the dietary data processing and analysis level. The focus is on nationally representative individual-level data, and additional types of dietary data, such as dietary biomarkers, household assessment, and food availability, are reviewed as alternatives. Practical guidance is provided to inform key decisions when designing dietary surveys and collecting, analyzing, and using dietary data. This article further identifies and describes existing global and regional dietary initiatives/data sets.

RESULTS

Harmonized and standardized primary individual-level dietary data collection, processing, and analysis worldwide are currently not available. Evaluation and decision-making should be based on best available data, that is, secondary nonharmonized yet to the extent possible, standardized individual-level dietary data. Existing initiatives differ substantially in methodologies, including survey design/representativeness, coverage, diet assessment, and dietary metric standardization and processing. Data gaps have been identified that were more profound for certain countries, certain dietary indicators across countries, population subgroups, representativeness, or time periods.

CONCLUSIONS

Optimizing worldwide dietary habits to improve population health requires systematically identified and evaluated data on a continuing basis. Leveraging existing available dietary data and efforts is an indispensable prerequisite for informed priority setting targeting the intersections between diet and disease.

Measurement Errors in Dietary Assessment Using Self-Reported 24-Hour Recalls in Low-Income Countries and Strategies for Their Prevention

Securing accurate measurements of dietary intake across populations is challenging. Of the methods, self-reported 24-h recalls are often used in low-income countries (LICs) because they are quick, culturally sensitive, do not require high cognitive ability, and provide quantitative data on both foods and nutrients. Measuring intakes via 24-h recalls involves 1) collecting data on food intakes, 2) the appropriate use of relevant food-composition data for calculating nutrient intakes, and 3) statistically converting observed intakes to "usual intakes" for evaluating nutrient adequacy or relations between foods and nutrients and health outcomes. Like all dietary methods, 24-h recalls are subject to random errors that lower the precision and systematic errors that can reduce accuracy at each stage of the measurement protocol. Research has identified the potential sources of measurement errors in 24-h recall protocols and emphasized that sources of random error can be reduced by incorporating standardized quality-control procedures and collecting more than one 24-h recall per person, with the number depending on the study objective. Careful design of the initial 24-h recall protocol can take into account potential sources of systematic error, such as day of the week, season, age, etc. Other sources of systematic error (e.g., energy underreporting) can best be detected by including a reference measure (e.g., doubly labeled water to measure energy expenditure). Alternatively, 24-h recall intakes of energy can be compared with same-day weighed intakes. Nevertheless, very few studies in LICs have assessed the validity of 24-h recalls in their study settings or adopted recommended standardized protocols to mitigate random errors. Hence, efforts should be made to improve the assessment, analysis, and interpretation of self-reported 24-h recall data for population studies in LICs. Accurate and precise dietary intake data at the national level can play an essential role in informing food, nutrition, and agricultural policies; food fortification planning; and compliance to food-based dietary guidelines.

Overcoming Dietary Assessment Challenges in Low-Income Countries: Technological Solutions Proposed by the International Dietary Data Expansion (INDDEX) Project

An increasing number of low-income countries (LICs) exhibit high rates of malnutrition coincident with rising rates of overweight and obesity. Individual-level dietary data are needed to inform effective responses, yet dietary data from large-scale surveys conducted in LICs remain extremely limited. This discussion paper first seeks to highlight the barriers to collection and use of individual-level dietary data in LICs. Second, it introduces readers to new technological developments and research initiatives to remedy this situation, led by the International Dietary Data Expansion (INDDEX) Project. Constraints to conducting large-scale dietary assessments include significant costs, time burden, technical complexity, and limited investment in dietary research infrastructure, including the necessary tools and databases required to collect individual-level dietary data in large surveys. To address existing bottlenecks, the INDDEX Project is developing a dietary assessment platform for LICs, called INDDEX24, consisting of a mobile application integrated with a web database application, which is expected to facilitate seamless data collection and processing. These tools will be subject to rigorous testing including feasibility, validation, and cost studies. To scale up dietary data collection and use in LICs, the INDDEX Project will also invest in food composition databases, an individual-level dietary data dissemination platform, and capacity development activities. Although the INDDEX Project activities are expected to improve the ability of researchers and policymakers in low-income countries to collect, process, and use dietary data, the global nutrition community is urged to commit further significant investments in order to adequately address the range and scope of challenges described in this paper.