Comparing the Kitavans to his native Swedish population, Dr. Lindeberg found that despite a diet that was 70 percent carbohydrate (unrefined), the Kitavans had insulin levels below the 5th percentile of the Swedes.16 The average Kitavan native had an insulin level lower than 95 percent of Swedes. The body mass index of young Kitavans averaged 22 (normal) and it decreased with age.