Does sugar contribute to the development of diabetes?

Scientific evidence is lacking to link sugar (sucrose) intake up to 10% of energy to glycemic control or lipid profile in people with type 1 or type 2 diabetes.

It was previously believed that sucrose (table sugar) and other sugars contributed to the development of diabetes and that people with diabetes should avoid sugars. This belief was based on the assumption that sugars were more rapidly digested and absorbed than other carbohydrates and would therefore cause high blood glucose levels. In fact, sucrose and fructose actually produce a lower blood glucose response than equal amounts of many starches with high glycemic index like white bread and mashed potatoes. It is for this reason Diabetes Canada does not recommend the avoidance of sugars, and states that "added sucrose intake of up to 10% of total daily energy (e.g. 50 to 65 g/day in a 2,000 to 2,600 kcal/day diet) is acceptable", in addition to naturally occurring sugars in fruits, vegetables, and dairy products.

Can people with diabetes have sugar?

Yes, people with diabetes can consume sugar. Diabetes Canada does not recommend the avoidance of sugars but rather suggests that "naturally occurring and added sugars should be included as part of the daily carbohydrate allowance and as part of a healthy eating plan" for people with diabetes. Diabetes Canada advocates that in addition to naturally occurring sugars in fruits, vegetables and dairy products, sugars added to foods can contribute up to 10% of daily energy requirements without harmful effects on blood sugar or lipid control in people with diabetes.

Does eating sweet foods cause a sugar high followed by a low?

People often mistakenly think that eating sugar-containing foods causes a dramatic rise in blood sugar followed by an extreme low, causing fatigue and food cravings. In fact, in healthy people, blood sugar levels are kept within a narrow range, and fatigue and food cravings are rarely due to low blood sugar (or hypoglycemia). The body is able to defend blood sugar levels by secreting hormones that regulate the storage or release of blood glucose. Studies in humans have shown that sugar actually causes a smaller increase in blood sugar than eating certain starchy foods such as mashed potatoes and white bread.

To learn more about sugars and diabetes, see our resources Clips on Sugars - Sugars and Health, and Clips on Sugars - Understanding the Glycemic Index.