Speaker
Description
Keywords
Nutrition transition, Urbanisation, Tanzania, Food environment
Introduction
The proposed study aims to analyse the effect of the degree of urbanisation on households’ diets in Tanzania. A healthy diet forms the cornerstone of human development, as sufficient and adequate nutritional intake throughout life is a crucial determinant of an individual's health and productivity, as well as that of the next generation (Blakstad et al., 2022; Slawson et al., 2013; Swinburn et al., 2019). Globally, changes in lifestyle and increased availability of energy-dense foods have led to a change in diets and food-related behaviour, also called the nutrition transition (Popkin, 2015; Popkin & Ng, 2021; Steyn & Mchiza, 2014). Reflective of this is the simultaneous growth of urban spaces and the rate of obesity and overweight in Tanzania (Keding, 2016; Tanzania et al., 2019), where sub-populations struggle with underweight, overweight, and micronutrient deficiencies; the triple burden of malnutrition (Keding, 2016; Popkin, 2015).
Higher incomes have not consistently led to more diversified diets and better nutrition, in part, due to nutritious foods become more expensive in Tanzania (Ignowski et al., 2023). As a result, in urban areas, 9% of the total budget share is now spent on ultra-processed foods, with sugar-sweetened beverages, bread, and other products among the most popular products(Sauer et al., 2021). Processed and ultra-processed foods (UPF) have become commonplace among urban and rural populations (Cockx et al., 2018), irrespective of class (Sauer et al., 2021). Besides increased access to processed and ultra-processed foods, urbanisation brings other lifestyle changes that can affect a person’s overall health and weight. The transition out of agriculture and manual labour (Cockx et al., 2018), longer commutes, employment outside of the home, both the outside food environment as well as the home environment (such as less storage space), promote the consumption of processed food (Holdsworth & Landais, 2019; Miranda et al., 2019). This increased consumption of UPFs, sugar, and sugar-sweetened beverages (SSBs) often comes at the cost of consumers, by contributing to overweight, obesity, and diabetes, which can further lead to cardio-vascular and other non-communicable diseases (Alcaraz et al., 2021; Pagliai et al., 2021; Pietrantoni & Mayrovitz, 2022; Vitale et al., 2024).
While research has shown that there is an effects of urbanisation and the food environment on individual’s diet, it is not yet clear how varying degrees of urbanisation and the immediate food environment affects a household’s food consumption, in Tanzania (Ameye, 2023).
Objective and Research Questions
As urbanisation is often listed as a critical determinant of SSBs and UPF consumption (Dicken et al., 2023; Mazarello Paes et al., 2015), this study aims to comprehensively investigate the impact of the degree of urbanisation on dietary consumption patterns in Tanzania.
The research questions of the proposed research are:
- How does the relationship between the urbanisation and a household’s consumption of sugar, SSBs, and processed foods differ across varying degrees of urbanisation and time?
- How does the density of supermarkets surrounding a household affect consumption of sugar, SSBs, and UPFs?
- (How) do household characteristics, such as income, education of the household head, work outside of the home and food consumed from own production mediate the effects of urbanisation and supermarket density, on the consumption of sugar, SSB, and UPF?
Methods
This study aims to integrate longitudinal data from the Tanzania National Panel Survey with Global Human Settlement (GHS) data obtained from OpenStreetMap. Specifically, we aim to examine the impacts of urbanisation, represented by changes in population density, and shifts in the food environment, indicated by changes in supermarket density, on food consumption patterns. Through mediation analysis, we seek to show the underlying household-level mechanisms through which urbanisation and alterations in the food environment influence dietary habits.
Expected Results
Ameye (2023) and Cockx et al. (2018) have shown, that urbanisation in itself has an impact on sugar and processed food consumption. Therefore, we can likely assume an overall increase in sugar, SSB and UPF over time, but the relationship with the degree of urbanisation immediately around the household remains unclear. The effect of supermarkets can also be inconsistent, as the product range offered in the supermarket can differ, depending on the income of the neighbourhood (Holdsworth & Landais, 2019). While potentially offering higher food diversity, they also often are the main retailers of UPFs and have been shown to correlate positively with higher BMIs in Kenya (Holdsworth & Landais, 2019).
Previous research has shown that lower consumption of ultra-processed foods is not consistently associated with higher education or income (Dicken et al., 2023). Similarly, SSB consumption is inconsistently associated with income (Barrett et al., 2017; Han & Powell, 2013; Schneider et al., 2021). It is likely that increased income and education are not (like in HICs) negatively (Han & Powell, 2013) but positively associated with increased consumption of SSB and UFPS products (Marrón-Ponce et al., 2018), as these might represent a lifestyle products that are only accessible to those with higher incomes, making it more popular among them.
Relevance of Results
The findings of this study hold significant implications for public health policy and urban planning in Tanzania. The results may showcase that certain areas and household characteristics have significant impact on peoples’ diets, which can then be further explored in more detail.
