The low GI diet, or glycemic index diet, is a weight-loss plan based on the concept of eating foods that have a low impact on blood sugar levels. Originally developed to help people with diabetes control their blood sugar, the idea is to choose foods that do not cause your blood sugar levels to increase rapidly, thereby leading to weight loss. Nutrisystem and the Zone diet are two popular diets that are based on using the glycemic index to determine foods that will help you to lose weight.
What Is The Glycemic Index?
The glycemix index ranks foods based on how quickly they raise blood sugar (glucose) levels after eating them. If a food is given a high GI rating, that means that food has the potential to raise blood sugar levels faster than foods with lower GI ratings. When you eat foods that cause sugar levels to rise rapidly, the body responds with higher insulin levels and high levels of insulin are linked to many health problems.
The cells that make up our muscles and other tissues in our bodies get their main source of energy from glucose (sugar). Carbohydrates in the foods we eat and storage of glucose in our livers are the body’s two major sources of obtaining glucose. Whenever we eat a food that contains carbohydrates, our body breaks down those carbs and converts them into sugar. The sugar goes into our bloodstream and then it is distributed to the cells throughout our body providing us with the energy we need. Any excess sugar that is not immediately needed by the body is stored in a form called glycogen in our livers and muscles.
Our pancreas helps to regulate sugar in our bodies using two hormones – insulin and glucagon. When blood sugar levels are high in our body, insulin is released to move it from our blood into our cells. When blood sugar levels are low, glucagon helps to release the sugar in the form of glycogen that is stored in our livers. The entire process is a way of keeping our bodies fueled and maintaining a natural balance of blood sugar.
Keeping Things In Balance
When we eat foods that cause sugar levels in our bodies to rise rapidly, we disrupt the natural balance of blood sugar. Our bodies have a difficult time responding to high insulin levels or levels that go up and down too quickly, and over time is is possible to develop insulin resistance. Obesity, high blood pressure, stroke, heart disease, and type 2 diabetes are all health problems that are associated with insulin resistance.
How Foods Are Ranked on the Glycemic Index
Since only carbohydrates affect blood sugar levels, the glycemic index only ranks food and beverages that contain carbs. Determining the GI rating of foods is a complicated process. In a nutshell, it involves volunteers eating a measured amount of foods containing digestible carbohydrates and then having their blood drawn every fifteen to thirty minutes, for about three hours after they eat the food, to determine what impact the food has on blood sugar levels. The impact these foods have on the subject’s blood sugar is compared to tests performed when the subject consumes the same measured amount of pure glucose.
After testing, foods are given a glycemic index rank on a scale of 0 to 100. The following are the scores foods are given:
- Very Low: A GI of 39 or lower
- Low: A GI of 40 to 54
- Medium: A GI of 55 to 69
- High: A GI of 70 or higher
Some examples of low GI foods are All Bran cereal, rye kernel bread, baby Lima beans, green peas, apples, apricots, cherries, grapefruit, egg fettuccine, spaghetti, butter beans, peanuts, and custard. Of course, just because these foods have a low GI rating does not mean you can eat as much as you want of them at any given time. You still have to use common sense when measuring portions.
When you eat low GI foods, your body absorbs them more slowly so they are in your digestive tract for a longer period of time. This helps to control your appetite which in turn, can help with your weight management. Eating low GI foods also helps your body to keep its natural blood sugar balance.
What Can I Eat on the Low GI Diet?
The recommended range of daily intake of carbohydrates and calories depends on your weight. It also depends upon whether you want to maintain your current weight or whether you are trying to lose weight. If you weigh 130 pounds and want to maintain that weight, based on the recommended calorie intake of 13 -1 5 calories per pound, you would want to consume between 1690 and 1950 calories a day. Your carbohydrate intake is based on a percentage of your calorie intake – between 50% to 60%. Based on a weight of 130 pounds, at 50% your carbohydrate intake would be between 211-243 grams. At 60% it would be between 253-292 grams per day.
To make is simple, say I weigh 140 pounds and I want to maintain that weight. It is recommended that I take in between 13 – 15 calories per pound a day. I’ll go with the middle number of 14. So, my weight of 140 multiplied by 14 equal 1960 calories per day. Of those 1960 calories, I want 50% of them to be made up of carbohydrates. Since each carbohydrate has four calories, I take 50% of my daily calories of 1960, multiply that by 50% which equals 980 and then divide that by 4, giving me a number of 245. The 245 is the grams of carbohydrates I can consume daily. When I plan my daily meals, I want to the total calories to be no more than 1960 for the day and the total carbs to be no more than 245 grams for the day. And, I want those to be healthy carbohydrates.
Counting calories and carbs for each and every meal is what often causes people to give up on diets. However, when you look at the glycemic index of foods you get a better understanding of which foods will cause a dramatic spike in blood sugar levels and which ones won’t. It becomes easier to choose which healthy foods to eat because many of the foods you like will be on the low GI list.
Another thing to consider with the low GI diet is that some foods that we know are good for us actually have a high GI rating. For example, carrots have a high GI rating of 71 however, the rating was determined based upon the test subject consuming 50 grams of available carbohydrates in the food. With carrots, this would mean eating 1 ½ pounds at a time. Since we typically don’t eat that many carrots at one sitting, you have to be able to put things in perspective and not rule out healthy foods simply based on their GI rating.
On the other hand, some junk foods will have a lower GI rating and yet we know they are not healthy foods. Because fat slows the rate that foods leave the stomach, when it is present it lowers the GI of a food or meal. This is the reason potato chips have a lower GI than carrots however, common sense tells us the carrots are far more healthier for us than the potato chips. The bottom line is, even though some foods have a lower GI rating, it doesn’t mean you should eat them.
It’s important to understand that the glycemic index does not rank foods on how healthy they are, so following the low GI diet means understanding the difference between healthy foods and junk foods. If you choose foods that have a low GI rating but are high in calories, sugar, and saturated fats, you defeat the whole purpose of following the plan.
There are also some instances when it can be difficult determining the GI of foods and meals because packaged foods don’t always list the GI index on their labels. That being said, many healthy foods such as fruits, vegetables, dairy products, legumes and whole grains are naturally low on the glycemic index and there are plenty to choose from. When you formulate your low GI diet plan, it’s important that you focus on those foods.
Studies on the low GI diet have had mixed results, however, some high-quality studies have concluded that by choosing the low GI diet over other traditional diets, you are more likely to lose weight. Part of the reason this is true is because it is easier for people to stick with the low GI diet since it is not an extreme diet like many traditional diets. There are more foods to choose from and it is easier to incorporate it as way of eating rather than thinking of it as a diet.
More Low GI Diet Information
Before beginning any diet, it is always smart to speak with your doctor or nutritionist first, especially if you have health problems. And since it is impossible to cover everything you need to know about the low GI diet in this article, I’ve provided some additional reading material that will help you determine if the low GI diet plan is right for you.
The Glycemic Index Diet For Dummies
The Glycemic-Load Diet: A powerful new program for losing weight and reversing insulin resistance
Transitions Lifestyle System Easy-to-Use Glycemic Index Food Guide
The Complete Idiot’s Guide to Glycemic Index Weight Loss
Living the G.I. (Glycemic Index) Diet
The Low GI Diet Revolution: The Definitive Science-Based Weight Loss Plan
Low GI Recipes
500 Low Glycemic Index Recipes: Fight Diabetes and Heart Disease, Lose Weight and Have Optimum Energy with Recipes That Let You Eat the Foods You Enjoy
The Glycemic-Load Diet Cookbook: 150 Recipes to Help You Lose Weight and Reverse Insulin Resistance
The Complete Idiot’s Guide Glycemic Index Cookbook
The Good Carb Cookbook: Secrets of Eating Low on the Glycemic Index