Purpose The purpose of the social Life Cycle Assessment (LCA) method is to predict the social impacts on people caused by the changes in the functioning of one product chain throughout its life cycle. Changes in health status are very important experiences for people. The aim of this paper is to build a pathway between changes in economic activity generated by the functioning of a product chain and the changes in health status of the population in the country where the economic activity takes place. Methods Empirical and historical factors suggest that increased economic activity through growth in income leads to improvements in the health of a country's population. This empirical relationship is well known in economics as the Preston curve. Using this relationship, we design a pathway for social LCA impact assessment. This pathway may be used to explain or predict the potential impact caused by the modification of one product sector upon the health of a population. The Preston relationship usually is calculated for a cross section of countries. We assess whether the Preston relationship is valid when a single country is considered alone. Drawing from scientific literature regarding development, we define the context where the use of the Preston relationship is justified. We describe the general design of the Preston pathway, using a recalculated (panel based) relationship, and specify the conditions for its use. We apply it to the case of company B, a banana industry in Cameroon, for the period between 2010 and 2030. Results We highlight that the panel calculation of the Preston relationship remains significant when a country is considered alone. We suggest that the following conditions are required for the pathway to be used: (1) the activity is set within countries where the GDP per capita in purchasing power parity is less than $10,000 at the start of the period, (2) the assessed activity accounts for a significant part of the annual GDP and/or demonstrates obvi