Picture a roller coaster ride with plenty of ups and downs. That’s what your blood sugar and insulin levels look like over the course of a day. The highs that follow meals and snacks drop to lows later on. Learning to eat in a way that makes your blood sugar levels look more like a kiddie coaster with gentle ups and downs rather than a strap-’em-in, hang-on-tight ride with steep climbs and breathtaking drops can make a difference to your health.
How can you do this? A tool called the glycemic index (GI) can help. It rates carbohydrate-containing foods by how much they boost blood sugar (blood glucose). For people with diabetes, glycemic index can be used as one strategy to keep blood sugar levels under control. And there may be other benefits—low glycemic index diets have been linked to reduced risks for cancer, heart disease, and other conditions.
Glycemic Index
The Glycemic Index (GI) is a measure that ranks carbohydrates in foods according to how they affect blood glucose levels. A numeric value from 1 – 100 is assigned to each carbohydrate-rich food, with glucose (sugar) assigned a value of 100. The GI system divides carbohydrate foods into three categories:
Low GI Foods: 55 or less
Medium GI Foods: 56 – 69
High GI Foods: 70+
Foods with a low GI value (55 or less) are more slowly digested and absorbed, causing a slow rise in blood glucose. Less insulin is needed to combat this gradual rise in blood sugar.
Some examples of low GI foods are whole milk, barley, oats, berries, and beans.
Foods with a medium GI value (56 – 69) causes a medium rise in blood sugar, and a proportionate amount of insulin is released to combat this rise in blood sugar.
Some examples of foods with medium GI are pasta, potatoes, and brown rice.
Foods with a high GI value (>70) tend to get absorbed quickly, causing a faster rise in blood sugar with more insulin released to combat this sudden rise. Examples of foods with a high GI value are white bread, white rice, most breakfast cereals, candies, and cakes.
Related : Why Do I Feel Bloated?
Gentle Rain vs Floods
Here's a great analogy to explain the concept of GI - Imagine what happens when it drizzles and when it pours.
Gentle rain or a drizzle allows a garden or rain harvest to utilize the rainwater better. The water level does not rise and there is no flooding. The same effect happens when you eat foods with a low GI value. Sugar is digested and absorbed in the body slowly, leading to a gradual increase in blood sugar, which the body can use better.
On the contrary, think of a time when it pours. There are floods, and most water is wasted and runs off to the drains. Only a small percentage gets utilized! When you eat foods with high GI values, your body digests and absorbs them quickly, causing a sudden rise in blood sugar levels, and your pancreas must pump large quantities of insulin to combat it.
Insulin is a hormone that helps get the blood sugar (glucose) from the blood to the cells. Over time, when you eat more refined carbs and your body pumps out a lot of insulin, the cells in your body start to resist it. This increases the probability of becoming insulin resistant, which potentially leads to type-2 diabetes.
Factors affecting GI
Many factors can affect a food’s glycemic index, including the following:
Processing: Grains that have been milled and refined—removing the bran and the germ—have a higher glycemic index than minimally processed whole grains.
Physical form: Finely ground grain is more rapidly digested than coarsely ground grain. This is why eating whole grains in their “whole form” like brown rice or oats can be healthier than eating highly processed whole grain bread.
Fiber content: High-fiber foods don’t contain as much digestible carbohydrate, so it slows the rate of digestion and causes a more gradual and lower rise in blood sugar. (17)
Ripeness: Ripe fruits and vegetables tend to have a higher glycemic index than un-ripened fruit.
Fat content and acid content: Meals with fat or acid are converted more slowly into sugar.
Related : Am I Getting Enough Fiber?
Glycemic load
One thing that a food’s glycemic index does not tell us is how much digestible carbohydrate – the total amount of carbohydrates excluding fiber – it delivers. That’s why researchers developed a related way to classify foods that takes into account both the amount of carbohydrate in the food in relation to its impact on blood sugar levels. This measure is called the glycemic load.
A food’s glycemic load is determined by multiplying its glycemic index by the amount of carbohydrate the food contains. In general, a glycemic load of 20 or more is high, 11 to 19 is medium, and 10 or under is low. More on this later.
Bottom Line
The glycemic index, or GI, is a measure used to determine how much a food can affect your blood sugar levels. Several factors affect the glycemic index of a food, including the nutrient composition, ripeness, cooking method, and amount of processing it has undergone.
Following a low glycemic diet may offer several health benefits, as it could help balance your blood sugar level, lower your cholesterol and increase short-term weight loss.
About the authors:
Madur & Anitha Jagannath are certified Nutrition Consultants, in addition to their professions in technology and human resources. When Madur started feeling lethargic and slowing down, he started exercising regularly, became conscious of healthy eating habits and nutrition. He is an avid runner and does half-marathons often. At Voyage to Wellness, they attribute our reputation to the lasting customer relationships they have developed throughout the years. They believe in health & wellness and being fit, at all stages of people's lives.
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