See Larry Husten’s article for MedPageToday”
“Newly uncovered documents reveal that 50 years ago the sugar industry gave secret support to prominent Harvard researchers to write an influential series of articles in the New England Journal of Medicine that downplayed the negative effects of sugar.Instead, the articles shifted the blame from sugar to fat as the “dietary culprit” behind heart disease.
In recent years there has been growing awareness that decades of dietary policy demonized fat and ignored or played down the dangers of increased consumption of carbohydrates and sugars. Many believe this policy had a significant adverse effect on public health, contributing to the obesity and diabetes epidemics.”
Source: How Sweet: Sugar Industry Made Fat the Villain | Medpage Today
Remember that sugar doesn’t always refer to just table sugar. Starches -as in bread, potatoes, and peas – are easily and quickly broken down by the body into simple sugars.
Diabetic Mediterranean Diet 
The search for scapegoats. Not every “prominent Harvard researcher” who wrote “an influential series of articles in the New England Journal of Medicine” was supported by sugar. Mostly they supported each other, and even the ones who did are the ones who are responsible.