According to the 2019 edition of the Bloomberg Healthiest Country Index, Spain is the world's healthiest country. It surpassed Italy to bag the title. Among the top 10 countries, are four European nations including Iceland and Switzerland. Japan is the healthiest Asian nation. The index grades nations based on life expectancy and environmental factors. According to researchers, eating habits provide clues to health levels enjoyed by Spain and Italy, especially since the Mediterranean diet is common here.