From an historical perspective, it is easy to see that the investigators of diet have confused circular motion with progress. The very low carbohydrate diets of the pre-insulin era yielded to the high carbohydrate diets of the late 1920s and 1930s, and these gave way to the free diets of the 1930s through to the 1950s. The cycle then resumed with the low carbohydrate diet of the 1960s, the high carbohydrate/high fibre diet of the 1970s, the free diets of the latter part of the century and the reincarnation of the pre-insulin regimen in the form of the Atkins diet. The enthusiasts have come and gone, each claiming unique virtue and spectacular success
for their own particular regimen, and it would be hard to imagine a diet that has not at some stage constituted an article of faith in diabetes management. Almost all these diets worked some of the time, but we may suspect that few were followed with any degree of rigour for most of the time