The effect of nutritional composition on the Glycemic index and Glycemic load values
Mahalakshmi Murugesan*
Senior dietitian, Kauvery hospital, Trichy, India.
*Correspondence: dietitian.reGIonal@kauveryhospital.com
Definition
The GI provides information about how the body digests carbohydrates using a scoring system of zero to 100. Pure sugar has a score of 100. Nutrition experts used to classify carbohydrates as either complex or simple. For example, table sugar is a simple carbohydrate, while beans and grains are complex carbohydrates. While researchers once believed that complex carbohydrates were less likely to cause blood glucose spikes, further research found that the relationship between carbohydrates and blood glucose is more complex. GI accounts for this complexity by ranking foods according to how quickly they elevate blood sugar.
To assess GI, researchers gave volunteers without diabetes a test food that contained 50 grams (g) of carbohydrates. On a different day, they gave participants a control food, such as white bread or sugar that has the same amount of carbohydrates. They then compared blood sugar levels at regular intervals for both foods, which means GI is simply a way to compare the effect of various foods on blood glucose. The higher a food’s GI is, the more rapidly it elevates blood glucose.
A high GI food can cause blood sugar spikes, followed by rapid declines in blood sugar. As blood sugar declines, a person may feel hungry. Eating only high GI foods can cause a person to overeat since they will quickly feel hungry again after eating. Eating a diet with a low average GI may reduce a person’s risk of developing diabetes and heart disease. In people who already have chronic conditions, a low GI diet may reduce the risk of complications and prevent blood glucose spikes.
How Glycemic Load and Glycemic Index are related?
Your blood sugar levels are dependent on many factors, including insulin levels, how quickly sugar is absorbed into your bloodstream, and how much sugar (glucose) is in a meal per serving.
GI tells you something about how high your blood sugar could rise with certain foods, but it does not tell you how high your blood sugar will go when you actually eat the food. That’s where glycemic load comes into play.
GI gives you a more accurate picture of how food impacts your blood sugar levels by considering the following factors.
- The types of sugar and starches in the food
- The way your food is prepared
- Fat content
- Fiber and carbohydrate content
- Serving size
- Rate of absorption and digestion of food products
GI provides food’s real-life impact on your blood sugar. For example, Watermelon has a high glycemic index (80), but its low carbohydrate content per serving results in a glycemic load of only 5.
The GI scores are as follows
- Low GI foods: 1-55 or less
- Medium GI foods: 56-69
- High GI foods: 70 or above
Low GI foods (<55) |
Medium GI foods(56-69) |
High GI foods (>70) |
Dairy products |
||
Milk (full-fat, skim, soy)
Greek yoghurt Plain yoghurt Cheese (cheddar, swiss, brie, goat) Cottage cheese (paneer) |
Ice cream | Rice milk
Flavoured yoghurt |
Fruits |
||
Apple
Banana (Raw) Orange Dates Prunes Most Fruits |
Mango
Orange Juice Ripe Bananas Grapes Raisins Muskmelons (In Moderation) |
Watermelons Pineapples |
Vegetables |
||
Carrots
Beans Peas Non-Starchy Vegetables (Tomatoes, Spinach, Broccoli, Cauliflower) |
Sweet Potatoes
Plantains (Green Banana) |
Russet Potatoes
White Potatoes Pumpkins (Only If Consumed In High Gl) |
Cereals |
||
Rolled Oats
Steel Cut Oats |
Muesli
Millet Porridge Weetabix (Wheat Biscuits) |
Cornflakes
Cereal Bars Instant Oats Rice Porridge Other Breakfast Cereals (Chocos, Honey Loops, Fruits Loops, Cheerios) |
Carbohydrates |
||
Whole Grain Bread
Quinoa Buckwheat (Kuttu) Corn Tortillas Barley Chickpeas Lentils Soya Beans Kidney Beans Black Chickpeas |
Wholemeal Bread
Wheat Roti Brown Rice Basmati Rice Couscous Wholemeal Spaghetti Rice Noodles |
White Bread
White Rice Instant Noodles And Pasta |
Snacks and sugars |
||
Fructose
Unsalted Nuts Hummus Dark Chocolate |
Popcorn
Chocolates Sucrose Honey Maple Syrup |
Sodas
Rice Crisps Cheese Crackers Potato Chips Glucose cakes and cookies |
Certain foods with a very low GI value can also be consumed as part of a low GI diet plan. These foods include:
- Meats: Lamb and beef.
- Poultry: Chicken, duck, eggs, etc.
- Seafood: Tuna, sardines, shrimps, salmon, mackerel, kingfish, crab.
- Oils: Seeds and nuts.
What is the role of Glycemic Index concept in Carbohydrate Metabolism?
Glycemic index (GI) is a system of classifying carbohydrate-containing foods according to how fast they are digested and absorbed during the postprandial period. It is a measure of the quality of carbohydrates based on their direct effect on blood glucose levels during 2 hr after the meal.
Factors affect the GI of foods
- Macronutrient content, including protein and fat
- Fiber content.
- Types of sugar and starches.
- Ripeness and maturity of the food.
- Processing, preparation, and cooking methods.
- The physical form of the food.
- Anti-nutrients in the food, which are substances that can block the absorption of nutrients into the body.
Low Glycemic Diet
The low glycemic diet involves swapping out foods with a high GI for those with a lower GI.
Benefits
- Improved blood sugar regulation: Many studies have found that following a low GI diet may reduce blood sugar levels and improve blood sugar management in people with type 2 diabetes.
- 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.
- Improved cholesterol levels: One study showed that low GI diets reduce total cholesterol by 9.6% and LDL (bad) cholesterol by 8.6%. LDL cholesterol is also associated with an increased risk of heart disease and stroke.
- May help you lose weight: Some evidence suggests that low GI diets can promote fat loss. However, more research is needed to determine whether low GI diets are effective for long-term weight loss.
- May reduce the risk of cancer: Some studies suggest that people who consume high GI diets are more likely to develop certain types of cancer, including endometrial, colorectal, and breast cancer, compared with people on low GI diets.
- May reduce the risk of heart disease: Recent research has strongly associated high- GI and GI -diets with an increased risk of heart disease.
How to follow
A healthy, low glycemic diet should comprise mostly low GI foods, such as:
- Fruits: Apples, berries, oranges, lemons, limes, grapefruit
- Non-starchy vegetables: Broccoli, cauliflower, spinach, tomatoes
- Whole grains: Quinoa, barley, buckwheat
- Legumes: Lentils, black beans, chickpeas, kidney beans, green gram, Bengal gram.
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: Beef, lamb, pork.
- Seafood: Tuna, salmon, shrimp, mackerel, sardines.
- Poultry: Chicken, turkey, duck.
- Oils: Olive oil, coconut oil, avocado oil, vegetable oil.
- Nuts: Almonds, walnuts, pistachios.
- Seeds: Chia seeds, sesame seeds, flax seeds.
- Herbs and spices: Turmeric, black pepper, cumin, dill, basil, rosemary, cinnamon.
Although no foods are strictly off-limits on the diet, foods with a high GI should be limited.
Foods with a high GI include
Carbohydrate foods that are broken down quickly by your body and cause a rapid increase in blood glucose have a high GI rating. Some high GI foods are:
- Bread: White bread, bagels, naan, pita bread.
- Rice: White rice, jasmine rice, arborio rice.
- Cereals: Instant oats, breakfast cereals.
- Starchy vegetables: Corn.white potatoes.
- Baked foods: Cake, doughnuts, cookies, croissants, muffins.
- Snacks: Chocolate, crackers, microwave popcorn, chips, pretzels.
- Sugar-sweetened beverages: Soda, sports drinks, and carbonated drinks ideally, try to replace these foods with foods that have a lower GI whenever possible.
What are the risks of eating on the high glycemic index and glycemic load?
- The glycemic index helps you pick higher quality carbohydrates. However, it’s the total carbohydrate loads in your diet that ultimately affect blood sugar levels.
- Choosing low glycemic foods can help, but you must also manage the total carbohydrates that you consume.
- Also, the GI doesn’t take into account the overall nutritional value of a food. For example, just because microwave popcorn is in the middle of GI foods, doesn’t mean you should live only on microwave popcorn.
- There are many meal plans available. Make sure to ask how you can use information on the glycemic index to best manage your blood sugar levels.
What are the benefits of using the glycemic index?
- Choosing foods with low glycemic impact can help to keep your blood sugar levels low. However, you must also carefully adhere to the portion sizes recommended. Glycemic ratings aren’t only for those withdiabetes.
- Those trying to lose weight or decrease hunger also utilize the GI as a diet because it can control appetite. Because the food takes longer to digest in the body, a person can feel fuller for longer.
How to calculate glycemic load
GI is a great tool because you don’t need to be a math whiz to calculate it. Dietary gl is calculated by the amount of carbohydrate contained in a specified serving size of the food multiplied by the GI of that food and divided by 100.2
Mathematically,
GL = GI – available carbohydrate (G) /100
- 10 or lower – low glycemic load
- 11 – 19 – medium glycemic load
- 20 or higher – high glycemic load
Low-GI foods (10 or less) |
Medium-GI foods (11 to 19) |
High-GI foods (20 or more) |
|||
Foods |
GI |
Foods |
GI |
Foods |
GI |
Apple | 6 | Banana | 13 | Brown rice | 20 |
Carrots, boiled | 1 | Pearled barely, boiled | 11 | Cornflakes | 20 |
Cashews | 2 | Puffed rice cake | 17 | Dates | 25 |
Kidney beans | 8 | Spaghetti, whole wheat | 14 | Potato, boiled | 25 |
Lentils, dried and boiled | 7 | 1 cup boiled brown rice | 18 | 2 tbsp raisins | 27.3 |
Orange | 5 | 1 cup cooked oatmeal | 11.7 | ||
Peanuts | 1 | 1 tablespoon (tbsp) honey | 11.9 | ||
Pear | 4 | ||||
Skim milk | 4 | ||||
Watermelon | 8 | ||||
White bread (wheat) | 10 |
Glycemic index and diabetes
Glycemic index (GI) is a measure of how quickly a food can make your blood sugar (glucose) rise. Only foods that contain carbohydrates have a GI. Foods such as oils, fats, and meats do not have a GI, though in people with diabetes, they can affect the blood sugar.
In general, low GI foods increase glucose slowly in your body. Foods with a high GI increase blood glucose quickly. if you have diabetes, high GI foods can make it harder to control diabetes
Meal planning with the glycemic index
Choose foods that have a low to medium GI.
- When eating a high GI food, combine it with low GI foods to balance the effect on your glucose levels. The GI of a food, and its impact on people with diabetes may change when you combine it with other foods.
- The GI of a food is affected by certain factors, such as the ripeness of a piece of fruit. So, you need to think about more than the GI of a food when making healthy choices. When choosing meals, it’s a good idea to keep these issues in mind.
- Portion size still matters because calories still matter, and so does the amount of carbohydrates. You need to keep an eye on the portion size and number of carbohydrates in the meal you are having, even if it has low GI foods.
- In general, processed foods have a higher GI. For example, fruit juice and potatoes have a higher GI than whole fruit and whole baked potatoes.
- Foods higher in fat or fiber tend to have a lower GI.
- Certain foods from the same class of foods can have different GI values. Choose a variety of healthy foods keeping in mind the nutritional value of the whole meal as well as the GI of foods.
- Some high GI foods are high in nutrients. So balance these with lower GI foods.
Reference
- Https://www.routledge.com/the-glycemic-index-applications-in-practice/philippou/p/book/9781032097695
- Https://www.ncbi.nlm.nih.gov/pmc/articles/pmc7352659/
- Https://www.scielo.br/j/rn/a/kswfp85s4mkqqyfhhcwg8dz/
- Https://www.amazon.in/complete-glycemic-index-counters-foods-ebook/dp/b08ggb3x1p.
- Mann j, cummings j, englyst h, key t, liu s, riccardi g, summerbell c, uauy r, van dam r, venn b, vorster h, wiseman m: Fao/who scientific update on carbohydrates in human nutrition: Conclusions.
- Nutrition subcommittee of the diabetes care advisory committee of diabetes uk: The implementation of nutritional advice for people with diabetes.
Mahalakshmi Murugesan
Senior Dietitian