What is the glycemic index?
The glycemic index (GI) is a numerical scale used to rank carbohydrate-containing foods based on their potential to raise blood sugar levels. It ranges from 0 to 100, with pure glucose serving as the benchmark at 100.
- Low GI foods (55 or below): Cause a gradual rise in blood sugar.
- Medium GI foods (56-69): Cause a moderate rise in blood sugar.
- High GI foods (70 or above): Cause a rapid spike in blood sugar.
How does it work?
When you consume carbohydrates, your body breaks them down into glucose, which is then absorbed into the bloodstream, influencing blood sugar levels. Foods with a high GI are digested quickly, leading to a rapid surge in blood sugar. In contrast, low GI foods are digested more slowly,
resulting in a steadier rise in blood sugar.
Factors affecting glycemic index
Several factors can influence the GI of a food:
- Type of carbohydrate: Complex carbohydrates (found in whole grains, legumes, and vegetables) tend to have lower GI values than simple carbohydrates (found in sugar, white bread, and refined grains).
- Fiber content: Foods with high fiber content generally have lower GI values.
- Cooking methods: How a food is prepared can affect its GI. For example, boiling or steaming often results in lower GI values than frying or roasting.
- Ripeness: Ripe fruits tend to have higher GI values than unripe ones.
Benefits of a low GI diet
A diet rich in low GI foods offers numerous health benefits, including: - Improved blood sugar control: Beneficial for individuals with
diabetes. - Weight management: Can aid in weight loss or maintenance by
helping you feel fuller for longer. - Reduced risk of heart disease: May help lower cholesterol levels.
- Increased energy levels: By providing a steady supply of glucose to the body.
- Could benefit people with fatty liver: A low-glycemic diet could help reduce liver fat and liver enzyme levels in people with non-alcoholic fatty liver disease.
Incorporating low-GI foods into your diet
To enjoy the benefits of a low GI diet, focus on incorporating plenty of:
- Whole grains: Barley, quinoa, oats
- Legumes: Lentils, chickpeas, kidney beans
- Vegetables: Non-starchy vegetables like broccoli, cauliflower, spinach, tomatoes and carrots
- Fruits: Apples, berries, pears, whole oranges, grapefruit
- Healthy fats: avocados, nuts
Foods without a GI value or with a very low GI can also be enjoyed as part of a balanced low glycemic diet. They include:
- Meat: Mutton, lamb
- Seafood: Tuna, salmon, shrimp, mackerel, anchovies, sardines
- Poultry: Chicken, turkey, duck
- Oils: Olive oil, coconut oil, avocado oil, ghee
- Nuts: Almonds, macadamia nuts, walnuts, pistachios
- Seeds: Chia seeds, sesame seeds, hemp seeds, flax seeds
- Herbs and spices: Turmeric, black pepper, cumin, dill, basil, rosemary, cinnamon
- Some pastas: Semolina and whole grain pasta
Although no foods are strictly off-limits on the diet, foods with a high GI should be limited.
Foods with a high GI include:
- Bread: White bread, bagels, naan, pita bread
- Rice: White rice, jasmine rice, arborio rice
- Cereals: Breakfast cereals
- Starchy vegetables: Mashed potatoes, potatoes, french fries
- Baked foods: Cake, doughnuts, cookies, croissants, muffins
- Snacks: Chocolate, crackers, microwave popcorn, chips, pretzels
- Sugar-sweetened beverages: Soda, fruit juice, sports drinks
Ideally, try to replace these foods with foods that have a lower GI whenever possible.
Glycemic index vs. Glycemic load
It’s essential to distinguish between the glycemic index (GI) and glycemic load (GL). While GI ranks foods based on their potential to raise blood sugar, GL considers both the GI and the carbohydrate content of a serving. Therefore, a food with a high GI but low carbohydrate content (e.g., carrots) may have a low GL.
Note: The glycemic index is a valuable tool, but it’s important to consider other factors, such as overall diet quality, portion sizes, and individual metabolism, when making food choices. Consulting with a registered nutritionist / dietitian can provide personalized guidance.