Case Study 2 Economic growth and prosperity Japan best illustrates the relationship between narrow income spreads and improved overall health status between 1965 and 1 990 it leaped ahead of all other industrialized countries despite increased dietary fat and increased smoking rates Life expectancy was 63. 6 years for males and 67.8 years for females in 1955 By 1991 it had increased to 76. 1 for males and 82. 1 years for femalesCase Study 2 ： Economic growth and prosperity • Japan best illustrates the relationship between narrow income spreads and improved overall health status. Between 1965 and 1990 it leaped ahead of all other industrialized countries despite increased dietary fat and increased smoking rates. • Life expectancy was 63.6 years for males and 67.8 years for females in 1955. • By 1991 it had increased to 76.1 for males and 82.1 years for females