Informal food environment is associated with household vegetable purchase patterns and dietary intake in the DECIDE study: Empirical evidence from food vendor mapping in peri-urban Dar es Salaam, Tanzania

Abstract

We study the relationship between the food environment (FE) and the food purchase patterns, dietary intakes, and nutritional status of individuals in peri-urban Tanzania. In Africa, the prevailing high density of informal vendors creates challenges to characterizing the FE. We present a protocol and tool developed as part of the Diet, Environment, and Choices of positive living (DECIDE) study to measure characteristics of the FE. We mapped 6627 food vendors in a peri-urban settlement of Dar es Salaam, of which over 60% were semi-formal and informal (mobile) vendors. We compute and compare four FE metrics inspired by landscape ecology—density, dispersion, diversity, and dominance—to better understand how the informal food environment relates to food purchase patterns, diets, and nutritional status among households with persons living with human immunodeficiency virus (PLHIV).

Highlights

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  In Tanzania, a high density of informal vendors within this transitioning food system creates challenges to characterizing the food environment.

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  We develop four metrics inspired by landscape ecology to characterize formal, semi-formal, and informal food environments.

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  We use these metrics to evaluate associations to household food purchase patterns, energy intake, and nutritional status.

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  Vegetables, especially green leafy vegetables, were primarily sold by informal mobile food vendors, most of whom were women.

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  A greater density of vegetable vendors or informal vendors within 500 meters of a household is associated with a higher likelihood of vegetable purchases and lower energy intake.

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  The role of informal and semi-formal food vendors in supporting consumption of nutritious diets should not be discounted, and gender sensitive actions to promote their livelihoods is needed.