It's a warning that rings harshly in the ear of anyone with a sweet tooth. You're about to tuck into a bag of your favourite lollies when someone shrieks in horror: "Don't eat those! You'll get diabetes!!"
But do high-sugar foods really pose this risk?
It's true that diabetes is a disease where there's too much glucose — a type of sugar — in your blood. But just because you have high blood sugar doesn't mean eating a lot of sugar is what got you there, says Ian Caterson, Boden Professor of Human Nutrition at the University of Sydney.
In fact, the notion there's a direct link between eating sugar and developing diabetes is a myth, Caterson says.
However, eating too many sugary foods can lead to weight gain, a key trigger for the most common form of diabetes: type 2. But so can eating too much of many other unhealthy foods, not just those high in sugar.
"It is more being overweight — particularly around the waist — that is linked with type 2 diabetes than any particular food you eat," he says.
Body fat and insulin
Weight gain can lead to diabetes because extra body fat causes chemical changes in your body.
"We used to think fat was just a storage tissue but we now know it's more than that," Caterson says. It's an active tissue which produces hormones — chemical messengers that influence processes in the body, he says.
In particular, hormones produced by fat influence the activity of another hormone, insulin, which controls the uptake of glucose from your blood.
Glucose is the body's main source of energy and it comes from carbohydrates such as potatoes, bread, pasta and rice, fruit and milk.
After food is digested, the glucose is released and absorbed into the bloodstream. From there, it's transported into cells under the control of insulin, which is released from your pancreas.
But when you gain weight, hormones produced by the extra body fat may mean you start to need more insulin to process your blood glucose effectively. Eventually your need for insulin may be so high your pancreas cannot supply enough of it. The result is diabetes.
"People with diabetes have high blood sugar because they're still absorbing sugar from food, but they can't deal with it quickly and appropriately," Caterson says.
This build-up of glucose in the bloodstream eventually damages blood vessels, which can lead to heart attack, stroke and problems with the kidneys, eyes, feet and nerves.