Do you know Glycemic Index ?

If you ingest 100 G of glucose, your blood glucose level rises by 100%. It means, glycemic Index (GI) of glucose is 100

If you eat 100g of boiled potato blood glucose will rise by 78%. So,GI of potato is 78

In this manner GI of various foods has been determined.and
these foods are grouped in 3 categories as:

High: (65 -75%)

White wheat bread, wheat roti, boiled rice, Cornflakes,
boiled potato, french fries, sucrose (table sugar), popcorn carrots, rice crackers /crisps, honey.

Intermediate: (45 -55%)

Fruits ( banana, mango, orange, orange juice, apple,
ice cream, multigrain bread, chapatti, soft drinks ,spaghetti

Low (30 -40%)

Chole, rajmah, Mung, beans, peas, lentils, soybean milk, yogurt, dates, chocolates

All intact whole grains have a very low GI score.

Glycemic index is a number. It gives you an idea about how fast your intestines convert the carbs in a food into glucose. numbers.The smaller the number, the less impact the food has on your blood sugar. 

GI index applies only to carbs and not proteins or fats

Carbohydrates with a value less than 55 or less are more 

slowly digested, absorbed and metabolized and cause a 

lower and slower rise in blood glucose and, therefore less 

insulin levels

Individuals who followed a low-GI diet over many years were at a lower risk for developing both diabetes and coronary heart disease, age-related macular degeneration and atherosclerosis
. 
In simple words, eating low-glycemic index foods (GI value <=55) helps to control diabetes and prevention of chronic disease. 

Bottom Line

Diabetics are advised not to eat rice. The reason is the 
high glycemic index of rice (78) But you do not eat dry rice, it is 
It is mixed  with curds or chole or rajmah, 

 A mixture of rice with curds will bring down rice induced rise in blood sugar.(GI of curds is only 41%) 

Similarly, GI of chole, rajmah ,lentils,is only 25%, and the mixture of rice-chole or rice-dal will bring down blood glucose raised by the rice alone.

What about potato?

It is true that GI of potato is 78%. But you do not eat only potato in your meals. It is a mix of cereals, pulses, vegetables, curds which will bring down the potato induced rise in blood glucose significantly.

Protein content of potato is low(2g/100g) but its biological value is equal to that of egg protein. It is a good source of carbohydrate and it must be a part of our diet. You cannot discard it just because it has a high GI.

Potato has very low calories (80/100g), high nutritive value and fibre content.

Mango and bananas have GI of 51% which is much less than rice or potato. plus both mango and banana have adequate fiber, vitamins and minerals. and both fruits have low calories.(80/100g of mango and100 /100G of banana) 
So it is very safe to have one or two mangoes in summer and one banana every day.

Eating Marie biscuits and avoiding mango and banana is strange. 

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