In this study of 18 countries with a range of income levels, we found that individuals in countries with low gross national income consume fewer fruits and vegetables and spend a greater proportion of their income purchasing food than those in high-income countries. Absolute fruit cost was highest in communities of LICs, whereas vegetable cost was lowest in these communities adjusted by purchasing price parity). However, the costs of both fruits and vegetables (relative to household income) were substantially higher for individuals in countries with low gross national income than in other economic regions. Furthermore, in LICs, households spend 29% and 11% of their income to purchase one serving of fruits and vegetables, respectively, and the dietary recommendation of two servings of fruits and three servings of vegetables per day was unaffordable for 57% of individuals. Unsurprisingly, increased costs of fruits and vegetables relative to household income were associated with reduced consumption.
Households in LICs and LMICs spend a substantial proportion (roughly half) of their income on food (compared with 13% in HICs), with households in some countries (eg, Occupied Palestinian Territory, Bangladesh, Pakistan, and Zimbabwe) spending about two-thirds of their income on food (
figure 2). These findings are consistent with previous work showing that food spending ranges from 35% to 65% in MICs
23 and from 55% to 77% in LICs.
23, 24 However, our findings of the relative costs of fruits and vegetables could not be compared with previous work in LICs or MICs because few such countries systematically monitor the cost of food and disclose national statistics.
25 Moreover, the national estimates of the cost of major food commodities available from the World Bank
26 and the UN Food and Agriculture Organization
27 do not include fruits and vegetables.
The consumption of a variety of fruits and vegetables is important to a high-quality diet.
28, 29 In the PURE study, most participants consumed fewer than the recommended five daily servings of fruits and vegetables, and mean vegetable intake was lower than the recommended three daily servings in all economics regions except HICs (
table 1). In 2015, global fruit and vegetable intake was estimated to be lower than the average observed in our study.
30 Of note, previous estimates were mainly based on qualitative questionnaires, shorter dietary tools, or household surveys. These dietary tools are brief questionnaires in which a structured list of food items is absent and as few as one question might be used to estimate the consumption of a particular food type. This method does not include portion sizes to quantify level of intake and provides a less precise estimate of absolute intake than 24 h dietary recall or semi-quantitative food frequency questionnaires.
31 The household surveys are useful for monitoring food commodity use, but they might not be appropriate for measuring absolute dietary intake or energy intake because they reflect both intake and food lost through waste at the retail, food service, and household level.
32 Among studies of HICs using semi-quantitative food frequency questionnaires and with similar age and sex characteristics as the PURE study, our estimates of mean fruit and vegetable intake correspond closely with those in other similar populations (
appendix p 11).
33, 34
Our study has a few limitations. First, fruit and vegetable costs were not recorded in 80 communities (11 953 participants), most of which were in LMICs. Since fruit and vegetable costs might vary across communities, imputing costs was unlikely to reflect the heterogeneity in prices. Our sample included a small representation of participants in South Africa and Zimbabwe because of missing data for fruit and vegetable costs and household income. However, the participants of the PURE study and non-participants included in our analysis were similar in baseline characteristics, so potential biases resulting from exclusion of participants were likely to be minimal. Second, a true probability sampling approach was not used to select our study population. Such a method was not feasible because of the many practical constraints of studying food cost and availability in a wide range of countries and settings. The fact that sampling was not random should be considered when interpreting the generalisability of our findings but should not compromise the internal validity. Third, the costs of the different fruits and vegetables were collected at the community level and assumed to reflect the average cost that households would pay. The costs were collected from grocery stores located centrally in each community to ensure that the costs were representative of most households. Fourth, we did not account for seasonal differences in prices, since we did not collect the cost of fruits and vegetables in each community at different times of the year. However, these data were collected over several seasons for most countries (
appendix p 15). Because many of the countries have fairly uniform climate (particularly in LICs and MICs), the results are likely to provide a reasonable approximation of the average seasonal price for fruit and vegetable items in these communities.
Fifth, costs were collected for fruits and vegetables that were thought to be the most widely available in most countries, but not necessarily the cheapest or most regularly consumed items within all countries. The fruits and vegetables chosen were widely available across economic regions, with the exception of pears and cabbage in LICs (
appendix p 20). Furthermore, the least expensive fruit and vegetable items in each economic region were available for sale in most communities (
appendix p 21). The interpretation of the affordability of fruits and vegetables might be limited to these commonly available produce, and cheaper alternatives might have been accessible. Nevertheless, fruit and vegetable intake was assessed using country-specific food frequency questionnaires that reflected the individual food items most commonly consumed in each country, and we still found a strong graded association with fruit and vegetable cost. Additionally, the cost of fruits and vegetables were collected as non-sale prices, since sale prices might change on a daily or weekly basis, thus increasing the variability of estimates, whereas the non-sale prices would be expected to provide a more consistent estimate of costs within and across communities. Finally, the data presented are cross-sectional, and inferences cannot be made about the causal relation between affordability and consumption of fruits and vegetables.
This study provides an international comparison of fruit and vegetable costs and affordability using a standardised and validated instrument. Another important strength of this study is the large sample size and heterogeneity of the study population. Additionally, a large proportion of study participants are from MICs and LICs, for which limited information on food affordability is available.
Hunger and under-nutrition remain highly prevalent in many LICs and MICs,
35 and nutrition strategies in these countries often prioritise meeting the minimum energy intake over diet quality. The unaffordability of fruits and vegetables might be a large barrier to achieving these nutritional targets. Worldwide, 1·7 million annual deaths are estimated to be associated with low fruit and vegetable intake,
36 and many populations are unable to meet the dietary recommendations. Our results show that increased cost of fruits and vegetables relative to household income was associated with reduced consumption, highlighting the need for policies that expand affordability and availability of these foods, which might improve the diet quality of many populations, especially in LICs and LMICs.