A report published Thursday in the Mayo Clinic Proceedings challenges the notion that all calories are equal. A team of researchers conducted a literature review to assess the effects of carbohydrates. Their methodolgy compared starch, pure glucose and lactose to added sugars such as sucrose and fructose. (Fructose occurs naturally in fruit, but is mostly consumed as a sweetener, i.e., high-fructose corn syrup that is added to foods and beverages).

Their findings? Added sugars were significantly more harmful, and correlated to worsening insulin levels and glucose tolerance (a driver for pre-diabetes). The added sugars also had other negative health implications.

Alexandra Sifferlin @acsifferlin reports for Time:

“We clearly showed that sugar is the principal driver of diabetes,” says lead study author James J. DiNicolantonio, a cardiovascular research scientist at Saint Luke’s Mid America Heart Institute. “A sugar calorie is much more harmful.”

“We need to understand that it isn’t the overconsuming of calories that leads to obesity and leads to diabetes. We need to totally change that around,” says DiNicolantonio. “It’s refined carbs and added sugars that lead to insulin resistance and diabetes, which leads to high insulin levels, which drives obesity.”

If you’re interested in learning more about sugar consumption and its impact on human health, you may wish to visit SugarScience, a website collaboratively managed by faculty and researchers from UC San Francisco, UC Davis and Emory University. SugarScience is viewed as an authoritative source for evidence-based, scientific information about sugar and its impact on health.

Dr. Robert Lustig, a pediatric endocrinologist at UC San Francisco, told the New York Times:

“The goal of this is to provide just the unbiased science,” Dr. Lustig said, “in a way that the public can come to its own conclusions.”

UCSF is using the SugarScience website as part of a larger “sugar science initiative” it has launched in collaboration with other institutions nationally.