______________________
Abstract
Many low- and middle-income countries (LMICs) are experiencing profound changes in food environments, including a rapid growth of supermarkets and other modern retailers. Changing food environments can influence people’s diets, nutrition, and health. While in many LMICs, undernutrition and micronutrient deficiencies are still widespread, problems of overweight, obesity, and related non-communicable diseases are also massively on the rise. Supermarkets seem to contribute to overweight and obesity among adults, but effects on children and adolescents could possibly be different. Here, we review the available evidence about the implications of supermarkets for people’s diets, nutrition, and health. Particular emphasis is placed on recent studies from urban Kenya that used panel data and differencing techniques to identify causal effects on different age cohorts. The results from Kenya show that shopping in supermarkets contributes to higher consumption of processed and highly processed foods and lower consumption of unprocessed foods. These dietary changes lead to significant increases in the body mass index and the probability of being overweight/obese and pre-diabetic among adults. For children, the same increases in overweight are not observed. Instead, supermarket shopping increases child height-for-age Z-scores. Despite higher food processing levels, supermarkets enhance food variety and dietary diversity in the relatively poor households. The results confirm that the growth of supermarkets affects adult and child nutrition differently; while the effects on adults are negative, the effects on children are positive, especially in the Kenyan context where child undernutrition is still widespread. Better understanding the effects of changing food environments on different age cohorts and in different contexts is important to design strategies that can help to make food choices in LMICs healthier. More research in different geographical settings will be useful.
© 2020 S. Karger AG, Basel
Malnutrition in all its forms is holding back the development and well-being of people worldwide. Overall, more than 820 million people are currently undernourished [1], over 2 billion people are affected by micronutrient deficiencies, and another 2 billion people are overweight or obese with an elevated risk of developing diet-related non-communicable diseases (NCDs), including diabetes, hypertension, stroke, and cancer [2, 3]. All countries worldwide are currently affected by at least one form of malnutrition, 88% of all countries even face two forms, and 29% three forms of malnutrition [2]. Especially, low- and middle-income countries (LMICs) and their economies and health systems are under pressure, facing infectious and chronic diseases at the same time at national and community level, but sometimes also at household and even individual level.
In order to fight malnutrition in all its forms and to establish access to safe, nutritious, and sustainable diets, “business as usual” is no longer an option. A transformation of food systems towards healthier and safer food with lower environmental effects is urgently needed. Over the last decades, transformation in diets could be observed in many LMICs. However, these transformations were mainly driven by urbanization, technological innovations, and an expansion of mass media, and have led to an increased intake of processed foods, meat and dairy products, saturated and total fats, sugar, and energy-dense beverages [4, 5]. While more energy-dense diets are beneficial for people who suffer from hunger and insufficient energy intake, they foster overweight and obesity in others without necessarily contributing to more nutritious and sustainable diets.
The rapid spread and growth of supermarkets in LMICs, which is often referred to as the “supermarket revolution,” plays an important role in shaping food environments and consumers’ food choices and diets [6]. Supermarkets influence food prices, the types of foods offered, shopping atmosphere, and the way food procurement systems are organized [7]. While research on supermarkets and their associations with diets, nutrition, and health have mainly focused on high-income countries and on adults, evidence for African countries is scarce. Here, we review recent studies carried out in different LMICs. The main emphasis is on studies in Kenya, the only African country for which research on the nutrition effects of supermarkets is available. The studies in Kenya used panel data and statistical differencing techniques, thus also allowing robust causal inference about the effects of supermarket shopping on people’s diets, nutrition, and health. Furthermore, the studies in Kenya differentiated between the effects on adults and children, which is interesting as the impacts of supermarkets may not be uniform across age cohorts. After reviewing this research, we discuss possible policy implications and examples of interventions in the context of supermarkets in sub-Saharan Africa (SSA).
Background
Conversely to the growth of supermarkets in the USA and Europe (historically in the first two-thirds of the 20th century), the expansion of supermarkets in SSA is happening at a much faster pace and only started in the late 1990s [8]. Except for a few large supermarket stores in big cities, where fresh fruits and vegetables are available, the expansion of supermarkets in SSA is especially characterized by the increasing offer of processed, dry, and packed foods [6, 9].
While the transformation of agri-food systems can create opportunities for domestic agriculture and food industries, challenges and possibilities for consumers concerning food consumption, nutrition, and health exist [7, 10]. The way retail outlets and their businesses are organized changes food environments and consumers’ food choices. Pricing, advertising, positioning, and the availability of different products and brands directly shape food preferences and create desires. Due to higher quantities traded and more efficient supply chains, supermarkets can sell certain foods at lower prices. Furthermore, supermarkets offer a wider range of types and brands of foods than traditional retailers and a different shopping atmosphere. While over-the-counter purchases are common in traditional retailers, supermarkets are self-service outlets. Hence, shopping in supermarkets is more autonomous, encouraging spontaneous purchase behavior and thus also changing people’s food choices and diets [11]. Besides personal preferences, habitual and every-day shopping practices, consumers’ choices are also affected by changing lifestyles and society.
The implications of the supermarket revolution for nutrition and health in LMICs are not yet well understood. For adults, some studies reveal significant associations between supermarket purchases and changing diets and nutrition. Studies from Tunisia and Vietnam found improvements in dietary quality through supermarket shopping [12, 13]. Studies from Indonesia, Guatemala, and Kenya suggest an association with higher energy consumption and a shift towards more processed foods through supermarket shopping [9, 14, 15]. Furthermore, some studies show significant links between supermarket shopping, higher body mass index (BMI), and higher risk of overweight and obesity [16, 17].