Wheat, rice, corn, and potatoes provide the carbohydrates, most of the calories, for majority of humans on earth. We modern humans consume more glucose molecules than our prehistoric ancestors did!
The shift from hunter gatherer diet of meat & wild vegetation to, one, largely of starch, represents a profound change in the composition of the human diet. Yes, humans rely on starch as a major source of calories.
Obesity and diabetes have been around since humans started relying on starch for sustenance. Harvard researchers found that women who consumed diets high in starch and low in fiber had a two and a half fold increase in the risk of developing diabetes, compared with women whose diets were high in fiber and low in starch
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When blood sugar and insulin remains elevated or cycle- up & down rapidly, the body has trouble responding and over time, this could end something called insulin resistance. The main culprit is the starch like white rice, rice flakes, potatoes, pasta, cereals, baked goods with high Glycemic Index, GI!
Foods with high GI will raise your blood sugar levels rapidly to a very high levels. Foods that have a low GI value raise your blood sugar gradually and help regulate the sugar levels. Low GI foods are digested slowly that makes you feel fuller for longer.
A diet high in rapidly absorbed carbohydrates and low in fiber is associated with an increased risk of type 2 diabetes. White bread, Idli (a savory cake of South India) are high in GI.
Give up High GI food completely?
Of course not! Many people get benefit from having low GI foods, but it doesn’t mean that one should completely exclude other carbohydrates.
- Not all the carbohydrates have the same effect in your body. Some carbohydrate foods will give a quick rise in blood sugar levels and some will have a slower effect. For example, refined products, oatmeal, white rice, white bread, more cooked or processed food, more ripen fruit are generally high in GI. They break down in the body faster and quickly raise the blood sugar levels! Soft-cooked pasta, mashed potato, are high in GI. So, avoid over cooking, any food!
- Juice has a higher GI when compared to a whole fruit. The fiber and acids in fruit tend to lower the GI. Opt for a whole fruit rather than juice/drink.
- More acidic the food, lower the GI. Sourdough bread is low in GI when compared to other varieties of bread.
- Dried beans & legumes, most fruits, non-starchy vegetables, some starchy vegetables like sweet potato, jicama (Mexican turnip / doushu-Mandrin / mishirkhand-Hindi), whole wheat grain breads and cereals like barley, brown rice are considered low GI foods.
- A low GI food is usually the preferred choice but a high GI sports drink is perfect during and after intense exercise.
We eat foods in combination with other foods. American Diabetes Association recommends combining low GI foods with a high GI food to balance your sugar levels. When you combine High GI with low GI food, the final is a medium GI, a balanced meal! A diabetes meal plan involves choosing foods that have a low or medium GI and low in saturated / trans fats.
You just need to “Balance” the GI!
- A teaspoon of peanut butter is high in GI and whole meal bread is low in GI. Combining these to food will give you a medium GI!
- Half a bowl of cornflakes is high in GI and mixing it with milk that is low in GI will get you a medium GI breakfast meal! Embellish with fruits for additional nutrient value.
- A bowl of white rice is naturally high in GI. Reducing it to a medium GI will not only prevent the insulin spike, it also keeps you feel full for a longer time. But How? The answer is very simple. Replace 1/2 the bowl of rice with beans/meat and vegetables. You will get a medium GI dish with a pretty decent amount of protein, too!
Different carbohydrate have different effects on blood sugar levels!
It is obvious that food high in GI will raise the blood-sugar more than a food with a medium or low GI. For example, let us compare 50 g of available carbohydrate in peas and white bread. Carbohydrate from peas will raise blood sugar, only, 47% of that from white bread. Sounds interesting!
It is hard to know that glycemic index does not take into account the amount of carbohydrate in a food! But gone are the days when experts classified foods as good and bad based on the glycemic index, alone. There is a more useful rating system called Glycemic Load, that represents how much typical servings of different carbohydrates raise blood sugar and insulin demands. In simple terms, it is a ranking system that measures the amount of carbohydrates in a serving of food.
- Popcorn, air popped has a high GI (72) but low in carbohydrate 6-8g/ cup. Thus popcorn (plain with little salt) would have an overall lower impact based on the serving size.
- If you take more than the serving size, the blood glucose rockets upward and it will take longer time to get normal.
- Puffed millet, like popcorn, is low in calorie ( 1/2 cup / 20 g of puffed millet gives only 70 kcal) and high in GI. Adding milk, a teaspoon of honey and nuts/fruits will help to enrich the protein/vitamin. A quick, healthy, and satisfying breakfast meal!
- The serving size is the key towards meeting the nutritional goal
For glycemic index/Load value of commonly used items click- http://www.health.harvard.edu/newsweek/Glycemic_index_and_glycemic_load_for_100_foods.htm
You will be surprised to notice that an 80g of carrot will have the GI as low as 35 when comparded to 30g of white wheat flour bread with the GI as high as 71
The glycemic load numbers reflect the typical serving sizes that raises blood sugar.
| FOOD | Glycemic Index(glucose =100) | Serving Size (grams) | Glycemic Load per serving size |
| White wheat flour bread | 71 | 30 | 10 |
| Carrot, average | 35 | 80 | 2 |
Foods with GL under 10 are considered low -GL foods and have a little impact on your blood sugar.
Foods with GL between 10 and 20 is considered moderate – GL foods with moderate impact on blood-sugar.
Foods with GL above 20 is considered high-GL foods that tend to cause blood sugar spikes
In summary, replacing high GI food with low GI food will reduce the risk of type 2 diabetes. These dietary changes can be achieved by replacing refined products and starchy vegetables like potatoes with whole-grains, vegetables & fruits, beans, lean meats, low-fat dairy products and nuts
Healthy meal planning involves choosing foods that have a low or medium GI. It is not only the low calorie or GI, but also the serving size should be considered while planning a meal. Serving size has a direct impact on GI! To maintain weight, eat less calories and be more active.
References:
- http://www.nutritionfoundation.org.nz
- http://ginews.blogspot.sg/
- Matthias B Schulze, Simin Liu, Eric B Rimm, JoAnn E Manson, Walter C Willett, and Frank B Hu, Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women, Am J Clin Nutr 2004;80:348
- Simin Liu, Walter C Willett, Meir J Stampfer, Frank B Hu, Mary Franz, Laura Sampson, Charles H Hennekens, and JoAnn E Manson, A prospective study of dietary glycemic load, carbohydrate intake, and risk of coronary heart disease in US women Am J Clin Nutr June 2000 71: 1455-1461
- Walter Willett, JoAnn Manson, and Simin Liu, Glycemic index, glycemic load, and risk of type 2 diabetes, Am J Clin Nutr July 2002 76: 1 2745-2805
Kohila G 