Is the world converging to a 'Western diet'?

Abstract

Objective: To test the nutrition transition hypothesis of global dietary convergence to a 'Western diet'.

Design: Consumer-waste-adjusted FAO Food Balance Sheets are used to construct for each country a Western Diet Similarity Index (WSI), expressed as a ratio of calories from animal-sourced foods, oils, fats and sweeteners to total per capita calories. β-Convergence and associated speed are estimated by growth regressions using 1992-2013 panel data. Speed of convergence, a non-linear function of income per capita, globalisation and urbanisation, determines the steady-state or long-term global WSI. The long-term global WSI is compared with the WSI of the group of countries with the highest population-weighted average WSI. The group, determined by K-means cluster analysis, consists of sixteen Western countries.

Setting: Worldwide.

Participants: Not applicable.

Results: Strong evidence of global dietary convergence at a speed driven by income per capita, globalisation and urbanisation with a long-term WSI of 38 %. When compared with the WSI of Western countries (68 %), the hypothesis of global dietary convergence to a Western diet is rejected.

Conclusions: The nutrition transition is acting in two opposing directions. Some countries experienced positive and others negative WSI growth, slowing down the transition to a Western diet in the long run. Policies to further slowdown the transition by some countries to unhealthier dietary patterns are as important as policies to further speed up the transition by other countries to healthier ones.

Keywords: Global dietary convergence; Western diet; β-convergence.

Fig. 1

Western Diet Similarity Index (WSI) growth rates between 1993 and 2013