Previously, the amount of carbohydrate intake was considered to be directly related to the blood glucose response to different diets. Because of this, food that was included in the traditional diet plans was on the basis of the amount of carbohydrates. However, the concept of Glycemic Index (GI) has cleared that foods relative to glucose or white bread with similar carbohydrate contents does not have the same effect on glucose levels.
What is Glycemic Index (GI)?
GI is a measurement of carbohydrate-containing foods and their impact on blood sugar. In simple words, instead of counting the total amount of carbohydrate level in food, GI measures the actual impact of these foods on our blood sugar. It has managed to be a key player for prevention and management of diabetes, cardiovascular diseases and even some types of cancer.
Why is GI important?
The Glycemic Index has been able to decrease the risk of cardiovascular disease, prevention and management of diabetes, metabolic syndrome, stroke, depression and cancers of breast, pancreas, colon and prostrate. Hence, diets prepared on the basis of low GI will have food which has low glucose level. For example, kidney beans and lentils have less starch which would be recommended in diets.
How is GI measured?
According to the definition, GI ranks food on an ascending scale of 1-100 by measuring the actual blood sugar released on consumption. On the basis of this, all foods are classified into three general categories:-
- High glycemic index foods (GI 70 or above), that induce an immediate rise in the sugar level.
- Intermediate glycemic index foods (GI 55-69) that causes an average rise in the blood sugar.
- Low glycemic index foods (GI 55 or below) that causes gradual rise in blood sugar.
The Glycemic Index is calculated in two steps.
Typically, any food consumed in whatever size produces 50gms of available carbohydrate. Available carbohydrate is what can be easily digested, absorbed and metabolised by the body. These carbohydrates have a greater impact on the body than general carbohydrates as carbohydrates in general can’t be digested or absorbed easily. Insoluble fibres are a kind of general carbohydrates.
So, the available carbohydrates are equal to the amount of total carbohydrates less total amount of fibres.
After the food is consumed, the sugar levels are checked after two hours and the results are plotted thereafter. The summary of the result is what is called the Glucose “AUC” or area under curve. This shows the immediate impact of food on blood sugar.
In the second step, the food intake for calculation is one of the two relative foods: pure glucose or white bread. Once again, the blood sugar is checked over a period of two hours and the results are plotted. The following results are then compared to calculate the GI of the different food. For easier calculation, the relative food, white bread or pure glucose is given a value of 100. For example, if the research is to find the impact of lentils in comparison to white bread, the results are plotted and the AUC is found out to be 46% for lentils. In this case, the glycemic index for lentils is 46.
Low Glycemic Index Indian Foods
Though the food intake can’t be wholly controlled on the basis of GI, there are certain Low Glycemic Index Indian Foods which can be included to balance the sugar levels.
- Chickpeas (28) – It has fibres which can prevent sugar levels to elevate, hence it is a must to be included in diet for diabetics. You can prepare a taste curry for your rotis or prepare hummus for bread.
- Broccoli- Also known as ant diabetes super hero, this has high levels of fibres and low carbohydrates and is highly recommended in diabetes.
- Apple (38) – As always, an apple a day keeps the doctor away! Apples are filled with fibres and can be used as an alternative for those who have a sweet tooth. Other fruits are papaya, pears and grapes which help in controlling blood sugar.
- Dalia/Cracked wheat- More nutritious than white rice and refined flour, dalia has a better glycemic index than both as it has more fibre, vitamins and minerals. It is recommended for those who have diabetes, high cholesterol or high blood pressure.
- Bitter gourd (karela) – A compound called charantin in bitter gourd keeps the sugar levels low and has great benefits of controlling diabetes.
- Fenugreek (methi) seeds- These have chemicals and fibres that slows the process of absorption of sugar and helps in many ways to cope with diabetes. Soaking few methi seeds overnight and drinking the water in the morning will be the best way to start the morning.
- Drumsticks- Again, a great food to manage diabetes. Drinking a glass of this juice in the morning will do wonders!
- Raw onions- It has hypoglycemic effects which helps in managing the sugar levels and keeping them in control.
- Ragi- It helps in digestion and prevents over eating making you feel full for a long time. Another benefit of ragi is keeping the diabetes under control as it is high in fibres.
- Beans- A complete mixture of high quality carbohydrates, proteins and soluble fibre, this is the end of search for a good food item.
- Fish- A solution for heart related issues and is also a good meal for diabetes. Meats and fats don’t have GI as they don’t have carbohydrates but proteins.
- Whole grain bread- It is found that simply switching from white bread to whole grain has increased the sensitivity to insulin. Next time, don’t forget to read the ingredient and pick the loaf that says “whole grain”.
- Barley- Having barley instead of white rice can reduce the blood sugar by 70%.
- Nuts like walnuts, almonds and cashews are also low in GI
- Brown rice- Though the GI of brown rice and basmati rice is same, brown rice has a lot of fibres and is considered more nutritious.
Why Glycemic Index values are unpredictable?
Though the latest trend of healthy eating is Glycemic Index, there are few things that are still unexplainable. For example, the starch level for pasta noodles and whole grain bread is the same but the GI of whole grain bread is more than that of pasta noodles. This is because the 3-D structure of bread allows the enzymes present in the saliva to break the starch more which gives this result. And hence, it shows a greater Glycemic index.
Also, the GI impacts on the way of cooking. For example, some legumes prevent breakdown of the starch present and therefore has a low GI, unless overcooked. Moreover, if the legumes are converted into flour, the value of GI may tend to increase.
It is suggested that the diet should not be entirely relied on the glycemic index as it may vary for unhealthy food. Also, there are people including athletes who would need food items with high glycemic index as it provides quick dose of glucose during or after competition. Hence, it is necessary to maintain a diet which is according to the needs of a body.