Eggs and other nutrient-dense foods
are expensive in poor countries,
leading to child stunting,
while sugar and other nutrient-poor foods
are cheap in rich countries,
leading to adult obesity.
This month, senior research fellows at the International Food Policy Research Institute (IFPRI) Derek Heady and Harold Alderman published results of their study on ‘relative caloric prices’ in The Journal of Nutrition. Using International Comparison Program data for 176 countries and 657 standardized food products, Headey and Alderman compared the costs of a calorie from a given nutrient-dense food such as eggs to a calorie from a starchy staple.
The gist is that many healthy foods are much more expensive in poor countries, while many unhealthy foods are much cheaper in richer countries.
We also show that these food prices patterns do a good job in explaining international patterns in child stunting and adult obesity.
—Lead author Derek Headey, of IFPRI
Below, in excerpts from their blog article for the World Bank’s Data Blog (The high price of healthy food … and the low price of unhealthy food, 23 Jul 2019), is how authors Headey and Alderman further explain the significance of their findings.
Poor diets are now the number 1 risk factor in the global burden of disease (GBD), accounting for one in five deaths globally.
Too much sugar, fat and red meat increase the risks of heart disease, diabetes, cancer; all killers in later life (mostly in higher income countries).
Too little nutrient-dense fruits, vegetables, dairy, eggs, meat and fish are associated with wasting, stunting and micronutrient deficiencies in early childhood; all killers in early life (mostly in lower income countries).
Poor diets are therefore at the epicenter of a diverse range of health problems in a diverse range of places.
‘. . . The metric we use to analyze the global food system from a consumer perspective is the “relative caloric price” of a given food. Take eggs, for example: how expensive is an egg calorie in Niger compared to the most important staple foods in that country?
Egg calories in Niger are 23.3 times as expensive as a calorie from a staple food, such as rice or corn.
In contrast, egg calories in the US are just 1.6 times as expensive as staple food calories.
‘The map below illustrates how this relative caloric price for eggs differs across countries. . . .
Our analysis yields a striking result:
As countries develop, their food systems
get better at providing healthier foods cheaply,
but they also get better at
providing unhealthier foods cheaply.
Hence the problem in less developed countries is that poor people also live in poor food systems: nutrient-dense foods like eggs, milk, fruits and vegetables can be very expensive in these countries, making it much harder to diversify away from nutrient-sparse staple foods like rice, corn and bread. The problem in more developed countries is rather different: unhealthy calories have simply become a very affordable option. In the US, for example, calories from soft drinks are just 1.9 times as expensive as staple food calories and require no preparation time.
‘These price patterns are consistent with the so-called nutrition transition: as countries develop, diets diversify into more nutritious foods (though sometimes slowly), but they also diversify into unhealthy foods like soft drinks. . . . [G]enerally, higher milk prices correlate with increased prevalence of stunting, while the relative prices of sugar-rich foods are negatively associated with obesity prevalence (lower sugar prices increase obesity). . . .
[T]hat relative food prices differ so markedly and so systematically provides a very strong rationale for nutrition-focused food policies.
‘Closing the healthy food gap between rich and poor countries requires more diversified investments in agricultural R&D to improve productivity of nutrient-dense foods—an important implication for the CGIAR—as well as improvements in infrastructure and the broader business environment. . . .’
Read the IFPRI paper
The relative caloric prices of healthy and unhealthy foods differ systematically across income levels and continents, by Derek Headey and Harold Alderman, The Journal of Nutrition, 23 Jul 2019.
Read an article about the paper
High cost of healthy food linked to stunting, new study finds, by Teresa Welsh, Devex, 23 Jul 2019
Read a related IFPRI paper on animal-sourced foods and stunting
Animal sourced foods and child stunting, by Derek Headey, Kalle Hirvonen and John Hoddinott, American Journal of Agricultural Economics, Oct 2018
Read related findings by scientists at the International Livestock Research Institute (ILRI)
ILRI research report: The influence of livestock-derived foods on nutrition during the first 1,000 days of life, by Delia Grace, Paula Dominguez-Salas, Silvia Alonso, Mats Lannerstad, Emmanuel Muunda, Nicholas Ngwili, Abbas Omar, Mishal Khan and Eloghene Otobo, May 2018
ILRI briefing: The influence of livestock-derived foods on nutrition during the first 1,000 days of life, by Delia Grace, Paula Domínguez-Salas, Silvia Alonso, Mats Lannerstad, Emmanuel Muunda, Nicholas Ngwili, Abbas Omar, Mishal Khan, and Eloghene Otobo, Jul 2018
ILRI opinion piece: No one dietary choice is the answer to sustainable development—ILRI in ‘The Guardian’, by Jimmy Smith, 17 Aug 2016.
ILRI News blog article: Meat, milk, eggs can make a big difference in the first 1,000 days of life in low-income countries—New report, 4 Jun 2018
ILRI presentation: Livestock-enhanced diets in the first 1,000 days of life: Pathways to better futures in low-income countries, article published on 19 Jun 2018, and Livestock enhanced diets in the first 1,000 days: Pathways to healthy and sustainable futures in low-income countries?, and slide presentation by Silvia Alonso (ILRI), Mats Lannerstad (ILRI), Paula Dominguez-Salas (ILRI/LSHTM) and Nabila Shaikh (Chatham House) made at the EAT Stockholm Forum on 11 Jun 2018