Impacts of a New Supermarket on Dietary Behavior and the Local Foodscape in Kisumu, Kenya: Protocol for a Mixed Methods, Natural Experimental Study

Abstract

Background Access to healthy food is considered a key determinant of dietary behavior, and there is mixed evidence that living near a supermarket is associated with a healthier diet. In Africa, supermarkets may contribute to the nutrition transition by offering both healthy and unhealthy foods and by replacing traditional food sellers. In Kisumu, Kenya, a planned hypermarket (ie, a supermarket combined with a department store) will form the basis for a natural experimental evaluation. Objective The aim of this study is to explore the impacts of a new hypermarket on food shopping practices, dietary behaviors, physical activity patterns, and body composition among local residents and to identify concurrent changes in the local foodscape. We also aim to explore how impacts and associations vary by socioeconomic status. Methods We employ a mixed methods, longitudinal study design. Two study areas were defined: the hypermarket intervention area (ie, Kisumu) and a comparison area with no hypermarket (ie, Homabay). The study is comprised of 4 pieces of primary data collection: a quantitative household survey with local residents, a qualitative study consisting of focus group discussions with local residents and semistructured interviews with government and private sector stakeholders, an audit of the local foodscape using on-the-ground data collection, and an intercept survey of shoppers in the hypermarket. Assessments will be undertaken at baseline and approximately 1 year after the hypermarket opens. Results Baseline assessments were conducted from March 2019 to June 2019. From a total sampling frame of 400 households, we recruited 376 of these households, giving an overall response rate of 94.0%. The household survey was completed by 516 individuals within these households. Across the two study areas, 8 focus groups and 44 stakeholder interviews were conducted, and 1920 food outlets were geocoded. Conclusions This study aims to further the understanding of the relationship between food retail and dietary behaviors in Kenya. Baseline assessments for the study have been completed. International Registered Report Identifier (IRRID) DERR1-10.2196/17814

Cross-Sectional Association of Food Source with Food Insecurity, Dietary Diversity and Body Mass Index in Western Kenya

“…Follow-up data to be collected on the sample in this study will allow for longitudinal observations of the association between the exposure and the outcomes of interest [ 21 ]. Future studies should investigate intra-household variations and the associations of food source with BMI and dietary diversity in both adults and children, to get a better understanding of how age group may modify these associations.…”

“…This study used baseline data from the Hypermarket, Foodscape and Health study [ 21 ], an ongoing mixed-methods natural experimental study that aims to assess individual, household and population impacts of a new hypermarket in Western Kenya on dietary behaviours, food purchasing, physical activity patterns and BMI. In this natural experimental study, the intervention area was the Mamboleo area of Kisumu County (urban), where a new hypermarket was under construction at the time of data collection, and the control area was the Sofia area of Homabay county (peri-urban), where there is no hypermarket existing or planned.…”

“…The head of the household and the household member in charge of food purchasing completed the household survey. The household head was defined as the ‘adult member of the household who is accepted and recognised by the other household members as the head’ [ 21 ], and the household member in charge of food purchasing was defined as the member of the household who obtained the majority of the food for the household and was most responsible for decision making concerning household food source. The household survey included questions about household composition, food purchasing, travelling to buy food and food insecurity as well as anthropometric measurements for the children (age 17 or younger) in the household.…”

“…The food environment changes in LMICs described by the nutrition transition [ 12 ] are accompanied by changes in how people source their food. For instance, open air markets have been the main source of purchased food in these countries, but are facing competition from large supermarkets and hypermarkets (department store combined with a supermarket) [ 20 , 21 ], which can provide more stable access to a variety of healthy and unhealthy foods [ 22 ].…”

Comparison of household socioeconomic status classification methods and effects on risk estimation: lessons from a natural experimental study, Kisumu, Western Kenya

“…In this analysis, we, therefore, aimed to compare three methods of assessing household SES using data obtained from a natural experimental study [ 21 ] in an urban African city – Kisumu, in Western Kenya – with the end goal of understanding the sensitivity, specificity, inter-rater reliabilities, proportion of SES misclassifications and accuracy of three methods of household SES classification and the effect associated with the risk estimation of self-reported diabetes and hypertension.…”