The Fad-Free Diet: Glycemic Index, Glycemic Load and Dietary Fiber
This is the time of year when a lot of us are thinking about getting rid of those extra pounds that we put on over the holidays, and perhaps thinking ahead to swimsuit season. Thus, magazines are full of articles about diet and every day there are new advertisements for different weight loss products.
For several years now, many diet plans have revolved around the notion of the glycemic index of foods, which is an estimate of the average rise in blood glucose levels after eating a certain food, or of glycemic load, a ranking system of the carbohydrate content of foods based on their glycemic index. This has always seemed to be an attractive concept that is also easy to follow. Foods that have a high glycemic index cause blood glucose to rise rapidly. As a result insulin levels rise to try and compensate, and then an array of other hormones are released to try and re-establish biochemical balance.
Insulin is a complex hormone, with over 500 recognized actions in the body. Insulin resistance is a condition in which some of the cells of the body, primarily in the liver and in adipose or fat tissue and in muscle, become unable to respond to some of the actions of insulin. It is the opposite of insulin sensitivity. As a result, insulin levels begin to rise, until ultimately the pancreas can no longer keep up with the demand. Insulin resistance is known to be a key metabolic problem associated with many illnesses, including Type 2 diabetes, hypertension, high levels of triglycerides and sometimes cholesterol, polycystic ovarian syndrome and even some types of cancer. It is typically associated with an increase in abdominal obesity, though insulin resistance may also cause obesity.
There is an important article in this month’s issue of the journal, Diabetes Care that has examined the impact of the composition of the diet on insulin sensitivity, insulin secretion and fat in a study of 979 adults enrolled in the Insulin Resistance Atherosclerosis Study. The conclusions are interesting and important: glycemic index and glycemic load were not related to measures of insulin sensitivity or secretion, or to the amount of fat in the body. However, in line with other research studies, the intake of fiber in the diet was again found to have beneficial effects on insulin sensitivity, adiposity and the secretion of insulin by the pancreas.
The conclusions once again show us the importance of increasing fiber in our diets, and indicate that the diets based on glycemic index and glycemic load are probably on their last legs.
The study follows one using the Dietary Approaches to Stop Hypertension (DASH) diet published in the December issue of Diabetes Care. A well-conducted randomized showed that the diet, which is rich in fruits, vegetables, and low-fat dairy foods, lowered blood pressure and has beneficial effects on blood lipids.
The real trick is to follow some simple strategies for following through with your resolutions (see my post on January 4th), and to follow a balanced diet and exercise program. I only wish that there were some magic fix for dealing with weight problems, but sadly there does not seem to be. Despite an enormous amount of research, and thousands of diet plans, what we have learned is that some people will do fine on almost any kind of diet, but not everyone will benefit, and some diets can be risky if they are not well-balanced. In my book Healing, Meaning and Purpose, I outline some simple dietary principles that I have used with thousands of people with great success for over 25 years. In a nutshell:
1. Energy balance is important
2. Calories do count
3. What you include in your diet is as important as what you exclude
4. Make only moderate dietary changes at any time: making big dietary changes can be a pretty violent attack on your body and your mind
5. Avoid the “trans-fatty acids”
6. Try to consume some omega-3 fatty acids
7. Eat fewer simple carbohydrates: that advice still holds, despite the new study
8. Use weight management strategies that enhance your overall health and well-being
9. Take more exercise
I don’t think that it can get much simpler than that. Though when someone interviewed me recently, and asked for a one-liner, I said: “Avoiding eating anything white, unless it is a prescription medicine.” Overly simplistic, of course, but simple watch words that have helped an awful lot of people. Good luck!
Technorati tags: Diet, Glycemic index, Insulin resistance
Dr. Richard G. Petty, MD is a world-renowned authority on the brain, and his revolutionary work on human energy systems has been acclaimed around the globe.
He is also an accredited specialist in internal and metabolic medicine, endocrinology, psychiatry, acupuncture and homeopathy. He has been an innovator and leader of the human potential movement for over thirty years and is also an active researcher, teacher, writer, professional speaker and broadcaster. He is the author of five books, including the groundbreaking and best selling CD series Healing, Meaning and Purpose. He has taught in over 45 countries and 48 states in the last ten years, but spends as much time as possible on his horse farm in Georgia.
