Type 2 Diabetes

Type 2 Diabetes occurs when the body either cannot properly use insulin that is released or does not make enough insulin

  • Type 2 Diabetes Risk Factors. Diabetes Canada identifies  major risk factors for Type 2 Diabetes, including age, family history, ethnicity, obesity, high blood pressure, and lifestyle factors such as smoking, unhealthy diet, and physical inactivity, among others.
  • Added Sugars and Type 2 Diabetes. Recent meta-analyses indicate that consumption of sugar, added sugars or total sugars does not increase the risk of Type 2 Diabetes. Epidemiological studies suggest an association between drinking large amounts of sugars-sweetened beverages and an increased risk of Type 2 Diabetes; however this may be due to an overall unhealthy lifestyle pattern. 
  • Sugars and Carbohydrates in the Diets of Individuals with Type 2 Diabetes. Diabetes Canada 2018 Clinical Practice Guidelines state that individuals with Type 2 Diabetes may substitute added sugars for other carbohydrates as part of mixed meals up to a maximum of 10% total daily energy intake, and should choose low glycemic index foods more often.

Type 2 Diabetes Risk Factors

There are several factors that increase your risk of developing Type 2 Diabetes (1, 2). Diabetes Canada identifies the following risk factors for Type 2 diabetes:

  • Age – 40 years or over
  • Genetics – e.g. having a parent, brother, or sister with diabetes
  • Certain ethnicities - e.g. African, Asian, Hispanic, Indigenous, or South Asian descent
  • Having obesity/overweight, especially individuals with excess abdominal weight
  • Health complications – e.g. impaired glucose tolerance, high blood pressure, high cholesterol or other fats in the blood
  • Certain diagnosed conditions – e.g. polycystic ovary syndrome, psychiatric disorders, obstructive sleep apnea 

Research suggests that the most important risk factor for Type 2 Diabetes is obesity, which can result from consuming excess Calories compared to the amount required on a daily basis for normal body functions, movement, and physical activity (2).

Excess calories from all foods and beverages increases risk of obesity, a risk factor for chronic diseases

Added Sugars and Type 2 Diabetes

Does consuming sugar give you diabetes? Recent evidence from meta-analyses indicates that consumption of sugar, added sugars, or total sugars does not increase the risk of Type 2 Diabetes (3, 4). Instead, current evidence suggests that any association between sugars and Type 2 Diabetes is mediated through the contribution of calories from sugars, which can lead to weight gain if consumed in excess. In randomized controlled trials and prospective cohort studies where sugars are isocalorically exchanged for other sources of carbohydrates, no differences in weight are observed between the two sources of calories (4). However, in studies where sugars contribute excess calories to the diet, weight gain does occur, which could contribute to increased risk of Type 2 diabetes.

Epidemiological studies have shown an increased risk for Type 2 Diabetes with higher intakes of sugars-sweetened beverages (5, 6). However, diet and lifestyle patterns characterized by high consumption of sweetened beverages (e.g. these diet and lifestyle patterns also tend to have higher energy intakes, diets higher in fat and sodium, and lack of physical activity) suggest that the association relies on overall unhealthy lifestyle patterns and dietary habits, rather than on total sugars, fructose-containing sugars or sucrose specifically.

Avoiding consumption of excess calories, from all sources, including sugars, can assist in controlling weight gain, a risk factor for Type 2 Diabetes.

Sugars and Carbohydrates in the Diets of Individuals with Type 2 Diabetes

For people living with Type 2 Diabetes, Diabetes Canada 2018 Clinical Practice Guidelines  (7) recommend the following related to sugars and/or carbohydrates in foods:

  1. The macronutrient distribution as a percentage of total energy can range from 45 to 60% carbohydrate, 15 to 20% protein and 20 to 35% fat to allow individualization of eating plans based on treatment goals and personal preferences.
  2. Sugars may be eaten in moderation by people with diabetes. In addition to naturally occurring sugars in fruits, vegetables, and dairy products, sugars added to foods may be substituted for other carbohydrates as part of mixed meals up to 10% of total daily calories, provided adequate control of blood glucose, lipids and body weight is maintained.
  3. People with diabetes should choose low Glycemic Index (GI) foods more often than high GI foods to help optimize glycemic control.

The GI is a tool to measure the body's blood glucose response to the intake of foods containing carbohydrates. The GI uses a numbering system to label foods as low GI (less than 55), medium GI (55-70) or high GI (more than 70). Foods with a high GI result in a rapid increase in blood glucose than foods with a low GI.

However, it is important to note that the GI system does have some limits, including:

  • The GI of a single food may change when it is eaten with other foods as part of a meal or snack;
  • High GI foods can also be part of a healthy diet. For example, parsnips, winter squash and rutabaga have a high GI but are also rich in fibre, vitamins, and minerals.
  • The GI of a food may vary depending on how it is processed or where it was grown. For example, converted rice has a low GI, basmati rice has a medium GI, and short-grain rice has a high GI as shown in the table below.

Glycemic Index of Various Foods

  Low GI (<55) Medium GI (55-70) High GI (>70)
Grains and Starches
All cereals provide energy, vitamins, and minerals. Whole grain and bran cereals also provide fibre.
Cereals All Bran™, Steel Cut Oats, Oat Bran Shredded Wheat™, Quick Oats Rice Krispies™, Corn Flakes™, Bran Flakes™, Cheerios™, Instant Oats
Breads Stone Ground Whole Wheat Bread, 12-Grain/Mixed Grain Bread, Pumpernickel Bread Whole Wheat Bread, Rye Bread, Sourdough Bread White Bread, White Bagel, Kaiser Roll
Grains/Pasta Pasta (cooked al dente), Converted or Parboiled Rice Basmati Rice, Brown Rice, Couscous Instant Rice
Fruits and Vegetables
High GI vegetables such as parsnip, rutabaga, and winter squash, are also rich sources of vitamins, minerals and fibre.
Starchy Vegetables Sweet potato, Green peas, Yams Raw Carrots, Baked Potato with Skin, New Potato, Corn Baked Potato without Skin, Mashed Potato, Parsnip, Rutabaga, Winter Squash
Fruit and Fruit Juices Apple, Orange, Strawberries, Peach, Cherries, Grapes, Apple Juice, Orange Juice, Grapefruit Juice Banana, Raisins, Apricots, Grape Juice, Cranberry Cocktail Watermelon, Dried Dates
Milk Products
Milk products provide important minerals for bone health including calcium, phosphorus and magnesium. 
  Milk, Plain Yogurt, Sweetened Yogurt, Chocolate Milk Sweetened Condensed Milk  
Legumes, including beans and lentils, are an excellent source of protein and fibre.
  Lentils, Kidney Beans, Chickpeas, Baked Beans    
Maple syrup, brown sugar, honey, and white sugar (sucrose) are all mainly carbohydrates and provide the same number of calories (4 Calories per gram).
  Fructose Table Sugar (Sucrose), Brown Sugar, Honey Glucose (GI = 100)

Source: International table of glycemic index and glycemic load values: Am J Clin Nutr 2002;76:5-56

For more information, additional resources include:

Recent news items include: 
  1. Diabetes Canada. 2018 Clinical Practice Guidelines. Screening for Diabetes in Adults.
  2. Diabetes Canada. 2018 Clinical Practice Guidelines. Reducing the Risk of Developing Diabetes.
  3. Tsilas SC et al., Relation of total sugars, fructose and sucrose with incident type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies. CMAJ. 2017;189:E711-20.
  4. Rippe JM et al. Added sugars and risk factors for obesity, diabetes and heart disease. Int J Obes (Lond). 2016 Mar;40 Suppl 1:S22-7.
  5. Imamura F, et al. Consumption of sugar-sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes: systematic review, meta-analysis, and estimation of population attributable fractionBr J Sports Med 2016;50:496–504.
  6. Lean ME, Te Morenga L.. Sugar and Type 2 Diabetes. Br Med Bull. 2016 Dec;120(1):43-53.
  7. Diabetes Canada. 2018 Clinical Practice Guidelines. Nutrition Therapy.