Do supermarkets contribute to the obesity pandemic in developing countries?

Abstract

Objective: Many developing countries are undergoing a nutrition transition with rising rates of overweight and obesity. This nutrition transition coincides with a rapid expansion of supermarkets. The objective of the present research is to study whether supermarkets directly contribute to overweight and other changes in nutritional status. Design: This research builds on cross-sectional observational data. Householdand individual-level data were collected in Kenya using a quasi-experimental survey design. Instrumental variable regressions were employed to analyse the impact of supermarket purchase on nutritional status. Causal chain models were estimated to examine pathways through which supermarkets affect nutrition. Setting: Small towns in Central Province of Kenya with and without supermarkets. Subjects: A total of 615 adults and 216 children and adolescents. Results: Controlling for other factors, buying in a supermarket is associated with a significantly higher BMI (P = 0·018) and a higher probability of overweight (P = 0·057) among adults. This effect is not observed for children and adolescents. Instead, buying in a supermarket seems to reduce child undernutrition measured by height-for-age Z-score (P = 0·017). Impacts of supermarkets depend on many factors including people's initial nutritional status. For both adults and children, the nutrition effects occur through higher food energy consumption and changes in dietary composition. Conclusions: Supermarkets and their food sales strategies contribute to changing food consumption habits and nutritional outcomes. Yet the types of outcomes differ by age cohort and initial nutritional status. Simple conclusions on whether supermarkets are good or bad for nutrition and public health are not justified.

The nutrition transition and indicators of child malnutrition

“…In that study, Kimenju et al (2014) found that an increase in the consumption of processed foods purchased in supermarkets did not lead to higher rates of overweight among children and adolescents, but was associated with higher height-for-age Z-scores and reduced rates of severe stunting. The mechanisms for this negative relationship between the nutrition transition and child stunting are not entirely clear and deserve further research with micro-level data.…”

Globalisation of agrifood systems and sustainable nutrition

“…Rather, supermarket purchase reduces child undernutrition and has a positive impact on body height (51) . For both adults and children, impacts occur through the same mechanisms, namely higher energy consumption and a higher share of energy from processed foods.…”

“…In addition, we collected individual-level data from household members, including anthropometric measures. In total, we took individual data from 615 adults and 216 children and adolescents (51) . While 41 % of the adults in the sample are either overweight or obese, only 10 % of the children and adolescents fall into this category.…”

“…This decision may be correlated with other observed and unobserved characteristics that could influence nutritional status through various pathways, thus leading to what is called self-selection bias in the impact evaluation literature. To control for confounding factors and possible self-selection bias, we estimated various regression models with instrumental variables (51,52) . The estimation results suggest that supermarkets contribute indeed to rising waistlines among adult consumers in Kenya.…”

“…Mean value is significantly higher than that of the other group: * P < 0·1; ** P < 0·05; *** P < 0·01. Source: Adapted from (51) . …”