What You Don’t Know About The Glycemic Index

The Glycemic Index (GI) is a method of classifying foods according to their potential to raise blood glucose levels.
Let’s back track for a second. Insulin is a hormone produced by special cells of the pancreas of healthy individuals in response to increased blood glucose concentration, among other things. The primary role of insulin is the transport of glucose from the bloodstream into the the muscle and fat cells. In response to low blood glucose concentration, a hormone called glucagon is secreted by special cells in the pancreas which releases glucose from liver glycogen stores. The body must be able to maintain blood glucose levels within a certain range to function optimally. Both insulin and glucagon help to accomplish this. In individuals with diabetes, these hormones do not function properly. ​

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There is a myth that carbohydrates stimulate insulin release and insulin stores fat, therefore carbohydrates make you fat. Research has been twisted by popular media to perpetuate this fear.
Research on the GI shows that certain carbohydrates cause blood glucose levels to rise and fall more rapidly than others. Those foods that create a dramatic rise and fall of blood sugar (high-glycemic) may leave us feeling hungrier more quickly than foods that are lower on the glycemic index. The terms “fast and slow moving/releasing carbs” are also popular. Eating foods lower on the glycemic index can be especially important for individuals with diabetes since fluctuations in blood glucose levels to either extreme can be fatal.
So, looking at the glycemic index, an equal amount of carbohydrate from white bread and barley will produce two different glycemic responses. Not ALL carbohydrates are bad for you and they will not make you fat.
Generally, consuming more calories than you are burning is what makes you gain weight. Being smarter about the types of foods you eat, including the type of carbohydrates, can aid in weight control both physiologically and psychologically. 
There is a caveat to whether or not selecting foods based on the GI really offers any weight control benefits. Foods on the glycemic index are tested in isolation, which means they are tested while being ingested on their own with no accompanying foods.  Individual foods produce a wide variety of blood sugar responses and foods affect blood sugar differently when combined with other foods.  Researchers and practitioners question the utility of the GI because people do not tend to eat foods in isolation the way these foods are tested in the lab.
With that being said, low glycemic foods tend to be more minimally processed and higher in fiber. 
Bottom line: each macronutrient (protein, fats, carbs) is required by the body to function optimally and it is unwise and dangerous to completely cut out or severely limit any one of them. Weight gain isn’t caused by one food group - you can’t point the finger at any one of them, but you can point the finger at yourself.  If you are consuming more calories than you are burning each day, that will cause weight gain.  You can lose weight by decreasing your calorie intake or exercising more, or a combination of both is best.  If you have a chronic disease or other health complication, more may need to be done to see weight loss results. See a qualified professional for assistance with exercise and/or nutrition.
Check out this link to see a chart of 100 popular foods on the glycemic index: https://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods

Author

Candice Canace has been a NASM certified personal trainer since 2014.  She specializes in women's fitness, weight loss, functional anatomy and overall health and wellness. Candice offers one-on-one personal training and small group training to women in Charlotte, NC. She also provides home and gym workouts through her online training app and is a certified online trainer.

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