It is likely that you or someone you know is on a diet, especially now that the holiday season is over and people are ready to shed those 10 pounds they gained from slugging down holiday meals. As a professional in the nutrition industry, I often have people ask me about low glycemic eating. What is it? How does it work? Can you write me out a meal plan?
To get started, let’s take a look at the physiology of fat cells. Fat cells, also known as adipocytes, are your body’s reservoir for energy under food deprived periods. Fat as a molecule has more energy potential per gram that protein or carbohydrates, hence the reason your body likes to store it. So the details: when you consume food, especially simple sugars and starches, your pancreas releases insulin, an anabolic hormone that is responsible for transporting glucose into cells for energy or to be stored as glycogen. This is fine so long as your energy expenditure is high enough to burn up the glucose in your blood. If your body does not require the glucose for energy, it can be broken down into a diverse molecule called acetyl-CoA. Acetyl-CoA residues can be converted into malonyl-CoA and linked together to form fatty acids. In the presence of insulin, these de novo fatty acids can be stored in fat cells, resulting in weight gain.
The idea behind low glycemic eating is to reduce the release of insulin from the pancreas. Without the presence of insulin in the blood stream, fatty acids cannot be transported efficiently into adipocytes for storage.
The glycemic index of food is determined by testing individual foods against a standard, usually white bread or simple sugars. By determining the blood sugar spike of a food ingested compared to the blood sugar spike of the standard reveals the glycemic index of that particular food. For example, if 100 grams of sugar results in a glycemic index of 100, any other food ingested will be compared to that score. If a 100 gram banana gives a glycemic index of 50, it would have a medium glycemic index. Full-fat cheese may result in a score of 15 and would be determined a low glycemic index food. Why? Because full-fat cheese results in a very low blood sugar spike and therefore requires very little insulin to be released from the pancreas. Remember, without insulin, fatty acids do not readily enter fat cells for storage.
While the exact glycemic index of foods can only be determined by testing against a standard, there are ways to approximate it. The carbohydrate, protein, fat and fiber content of food all contribute to the glycemic index. A rule of thumb, if the sum of protein, fat and fiber grams is equal or greater than the carbohydrate gram content, it could be determined a low glycemic index food. Protein, fat and fiber all impact the metabolism of carbohydrates in a food, thus blunting the blood sugar spike and reducing the amount of insulin required for food digestion and metabolism.
Do not feel discouraged if you do not grasp this concept right away. There are professionals who have devoted their entire career to understanding this concept. Low glycemic eating is becoming more and more popular as results continue to impress the masses. Remember, there is no calorie counting, just monitoring the glycemic index of food.
