Case study based on: Kuyper, E. M., Engle-Stone, R., Arsenault, J. E., Arimond, M., Adams, K. P., & Dewey, K. G. (2017). Dietary gap assessment: an approach for evaluating whether a country’s food supply can support healthy diets at the population level. Public Health Nutrition.
Cameroon is a lower middle-income country in Central Africa, with 35% (8.1 million people) living in poverty (World Bank, 2014). The country is undergoing a nutrition transition and faces a ‘triple burden’ of malnutrition, including undernutrition, micronutrient malnutrition and, increasingly, obesity and diet-related chronic disease (Gomez et al., 2013). The Nutrition in the WHO African Region report (WHO, 2017) put the prevalence of overweight or obesity among Cameroonian women aged 18-49 at 32.2%, while stunting remained stubbornly high (31.7%) among children under the age of 5 (UNICEF, 2019). Other sources have captured widespread micronutrient deficiencies, such as high levels of anemia among women aged 15-49 in 2014 (World Bank, 2019). These snapshots of the population’s nutrition status point to the need for a more fine-grained understanding of dietary contributors to nutritional status and the factors constraining the consumption of healthier diets.
The following case study summarizes research by Kuyper et al. (2017), who conducted a “dietary gap assessment” using food balance data from Food Balance Sheets (FBS) in Cameroon to determine if the nation’s food supply could support healthy diets at the population level. FBS provide information on food available for consumption at an aggregate, national level, taking into account domestic production, trade, food stores, and other uses. They are compiled annually for most United Nations member states and made publicaly available on FAOSTAT. While FBS do not directly capture individual consumption of foods or nutrients like a 24-hour Dietary Recall (24HR) survey, the authors reasoned that the availability of sufficient healthy, nutritious food to meet dietary guidance was a necessary (though not sufficient) precondition for consumption of quality diets across the population and that FBS could be a useful and accessible data source for determining the healthfulness of the food supply. This case study briefly summarizes the authors’ methods, findings and comments on the potential benefits and drawbacks of using food balance data to study population diet patterns.
Kuyper et al. (2017) illustrated their potential application of food balance data using Cameroon as a country case example and the Dietary Approaches to Stop Hypertension (DASH) dietary guidelines as a benchmark against which the quality of the Cameroonian food supply would be assessed. The DASH diet was originally developed for US populations, but the authors applied it to Cameroon in this study since there are no global food-based dietary guidelines and as Cameroon lacks its own national dietary guidelines. Futhermore, DASH diet recommendations seemed general enough to apply to locally available and preferred foods as the diet promotes food sources shown to correlate with adequate intakes of key macronutrients and micronutrients (Siervo et al., 2014; Philipps et al., 1999 as cited in Kuyper et al., 2017).
Kuyper et al. (2017) first classified local foods into seven food groups following the reference DASH diet. They calculated the target dietary energy contribution from each food group by averaging DASH-recommended serving size for foods in a food group and converting these amounts into calories, using nutrient values from the West African Food Composition Tables (2012) and the US Department of Agriculture’s National Nutrient Database (2011). Next, the authors drew on data from the FBS to determine the per capita energy in the food supply from each of these food groups. The researchers defined dietary gaps by comparing the estimated amount of each food group in the national food supply (in kcal/capita/day from FBS) to the target amount stipulated by the DASH diet.
Overall, the authors found that the food supply in Cameroon had, on average, adequate energy but inadequate foods that were nutrient dense. More specifically, the results from the study showed that Cameroonians’ main energy source was cassava and maize products, followed by sorghum, rice, and wheat. Palm oil provided the most energy from the fats and oils group. Fruits and vegetables, dairy products, and meat/poultry/fish/eggs were all deficient in the food supply, while the national per capita availability of fats/oils and legumes/nuts/seeds exceeded DASH dietary recommendations. Overall, the dietary gap assessment emphasized the urgent need to increase the quantity and quality of the national food supply for key food groups, by diversifying production or increasing imports (Kuyper et al., 2017).
This type of analysis is a useful example of how existing data (e.g. FBS) and dietary standards (e.g. DASH guidelines) can be used for food systems-related policy analysis. However, the approache also has certain limitations. FBS data do not adequately capture home production, food waste at the household level, seasonal or geographic variability, or individual-level consumption disparities. They provide a national-level longitudinal picture that offers a useful starting point for assessment. Where the food supply is found to be sufficiently healthful on a per capita basis, additional data from HCES, 24HR, or Food Frequency Questionnaires would help to diagnose the distributional sufficiency of access and intake. Though the authors re-adapted and grouped food items consumed in Cameroon to fit the stipulations of the DASH diet, the method was developed for application in the US and therefore reflects the preferences and serving sizes typical to the American population. As the authors recommend, applications of the Kuyper et al. method in the future should strive to use national dietary guidelines where possible.
The insufficient availability of diverse, nutritious food is likely to contribute to a range of health problems in countries like Cameroon. Analyses of widely available FBS data are a useful first step to understanding the nutritional sufficiency of the food supply and informing broad directions for policy intervention (e.g. through diversification of domestic production or imports). These types of agriculture and trade policies can be complemented by other data-informed measures focused on improving the access, affordability, and consumption of nutritionally important foods. Along with the FBS, Cameroon’s nationally representative 24HR recall data could be used to develop country-specific dietary guidelines to raise awareness of the health benefits of consuming a more diverse and balanced diet.
- Dash Eating Plan (n.d.). Retrieved from https://www.nhlbi.nih.gov/health-topics/dash-eating-plan
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