The Country Similarity Food Index is an attempt to quantify how similar the food in one country is relative to another, based on data from the Food and Agriculture Organization of the United Nations. By comparing the weight of raw food ingredients used in each country, a score is assigned that reflects the degree of similarity between the respective countries.
The Index was revised for the third and final time to better reflect which countries actually have the most similar food to each other. The first iteration put too great of a weight on the largest ingredients of diets. The second iteration put too little of a weight on animal products, like meat and dairy.
The final version of Country Food Similarity Index builds on the second version by applying a square root transformation to the data. However, instead of only having one method of calculation with unweighted data (except for applying a 30% minimum to the starches total), the new calculation has two methods averaged together. The second method weights the data at 30% for starches, 40% for fruits and vegetables, and 30% for meats and dairy. This results in a small improvement in the Index from the previous version. The articles about each country will be updated periodically to reflect the new and improved method.