What Is The Glycemic Index

The glycemic index (GI) is a measurement used to determine how much a specific carbohydrate-containing food will increase glucose levels. GI categories are broken down into low, medium, and high. Foods are assigned to these categories based on how much they raise blood sugar compared to how much pure glucose raises the blood sugar level.

Category Range
Low 1 to 55
Medium 56 to 69
High 70 and higher

The glycemic index is a great tool for understanding how your body metabolizes food. However, there are some limitations.

Limitations of the Glycemic Index

  1. Serving size: GI values do not factor in how much of a food you are eating in every meal, but are based on a typical serving size of a particular item.
  2. Nutritional information: Glycemic index does not give you nutritional details of food (such as total fat or protein).
  3. GI values can change: The GI value of food can change depending on how it is cooked, processed, and even can change based on what it’s eaten with.
  4. Incomplete GI database: The glycemic index database is comprised of foods that have been researched specifically for their effects on blood glucose. However, this database does not include all foods available.
  5. GI values are a range: GI values aren’t always exact and can come in a range for some foods. This can make it difficult to determine what category a particular food item belongs to.

Quick GI Food Guide To Follow

Low Glycemic Index Foods

  1. Non-starchy vegetables: broccoli, cauliflower, cucumber, spinach, mushrooms, onion, lettuce, brussels sprouts
  2. Whole grains: barley, rye, wild rice, wheat pasta, farro, bulgur
  3. Legumes: lentils, black beans, chickpeas, kidney beans, green beans, pinto beans
  4. Fruits: grapefruit, apples, apricots, peaches, plums, tomatoes, strawberries, raspberries

High Glycemic Index Foods

  1. Starchy vegetables: potatoes, parsnips, canned/frozen corn, winter squash
  2. Bread: white bread, bagels, whole grain bread,
  3. Fruits: dried dates, watermelon, pineapple, over ripe bananas
  4. Cereals: breakfast cereals, instant oatmeal, cream of wheat, grits
  5. Snacks: candy, crackers, chips, cookies, donuts, pretzels, pastries, cakes

Foods With No Glycemix Index

  1. Meat: beef, bison, deer, lamb, pork
  2. Poultry: chicken, turkey, duck, goose
  3. Seafood: tuna, salmon, shrimp, sardines, anchovies, mackerel
  4. Oils: olive oil, coconut oil, avocado oil, vegetable oil, oils that are liquid at room temperature
  5. Nuts and Seeds: sunflower seeds, almonds, peanuts, pecans, hazelnuts, walnuts


A low glycemic diet may help you manage your blood sugar levels, managing cholesterol, and losing weight, however, the GI does come with some limitations. For best results, speak to a doctor about your ideal diet and what techniques you should use for managing your diabetes.