Does a healthy diet cost more? links for World Food Day

World Food day is 16th October
See the FAO official website for details of this year's theme on healthy diet
UNICEF The State of the World’s Children 2019: Children, food and nutrition 
in terms of the UK they refer to children in a swamp of obesity.
OECD has recently published a report
The Heavy Burden of Obesity The Economics of Prevention
 Using microsimulation modelling, this book analyses the burden of obesity and overweight in 52 countries (including OECD, European Union and G20 countries), showing how overweight reduces life expectancy, increases healthcare costs, decreases workers' productivity and lowers GDP.
On this topic

Do people eat junk food because it is cheaper?

A systematic review of literature published in 2013
Do healthier foods and diet patterns cost more than less healthy options? A systematic review and meta-analysis of 27 studies from 10 countries did provide some evidence especially in terms of meat that healthier options were more expensive.

longitudinal study in UK found prices of healthy  foods rose quicker than healthier on 94 items 

The Growing Price Gap between More and Less Healthy Foods: Analysis of a Novel Longitudinal UK Dataset Nicholas R. V. Jones, Annalijn I. Conklin, Marc Suhrcke,
Pablo Monsivais

 In 2017 the same CEDAR research centre  found that cost of meeting the recommended dietary intake for  fruit and vegetables, oily fish, sugars, fat, saturated fat and salt  was between 3% and 17% more expensive.than other alternatives.

However there have been some disputes about metrics used to calculate costs . This IEA discussion paper from 2017 found the margins were  small. But as others have discussed factors such as time and access to healthy food outlets can also be key 

A government report obesity and the environment found a link between the number of fast food  outlets, child obesity and socio-economic background. Poorer people were likely to live near more fast food shops and to be overweight. It has an interesting map from 2016 showing the geographical spread of fast food outlets.