Insulin Index

A physiological measure

The Insulin Index (II) is a relative newcomer to the field of nutrition, but in order to fully appreciate its importance and contribution to our hormonal and metabolic balance, it is important to be familiar with the Glycemic Index (GI). Therefore, an explanation of the GI must precede that of II, and even though you may be already familiar with it.

The Glycemic Index is a physiological measure of the glucose released by foods upon digestion, as compared to swallowing an equal quantity of glucose. Initially it was used to provide a basis for carbohydrate exchange useful in diabetic diets [1]. Gradually, it was realized that the rate at which various carbohydrates release their glucose during digestion, was a far better index of their usefulness than their calories or any other similar measure, and especially so for diabetic individuals.

The procedure has the merit of recording through finger prick samples, the actual glucose released in the blood at specific and successive time intervals. It is not a theoretical precept, like the vitamin and other micronutrient contents of vegetables and fruits found in relevant charts and tables, which bear no relationship to what the average consumer buys. These vitamin and other charts refer to the freshest plant foods; but what the consumer buys is anybody's guess. This usefulness of the Glycemic Index has induced researchers to carry out a great deal of relevant work and produce substantial tables recording that of many plant foods [2].

The association of glucose with insulin

The Glycemic Index is far more important than usually realized. The main reason is the association of glucose with the hormone insulin secreted by the pancreas. Insulin follows closely the glucose in the blood. As glucose rises, so does insulin; and when glucose falls, insulin follows. Foods that release their glucose rapidly, cause an equally rapid rise of insulin. Something that is decidedly unhealthy, as it is associated with insulin resistance and in the end diabetes. Mixed meals, which contain less carbohydrate since they also contain some protein and/or fat, have been shown repeatedly to be secret promoters of abnormally high insulin secretions [3]. This is a bizarre and wholly unexpected reaction, since the insulin of such meals should have followed the diminished or slightly increased glucose and not skyrocket out of all proportions through still basically unknown processes.

Excessive glucose in the blood (and its accompanying insulin) is probably the most common cause of inflammation, but inflammation the site of which is usually difficult to fix with certainty. Such immoderate glucose is also the cause of excessive insulin.

The Insulin Index (II)

Excessive insulin acts as a blocking agent to fat breakdown. In fact insulin seems to act like a switch, and when in excess helps our organism to store fat for the lean days ahead, which was often the fate of our distant ancestors--but it is certainly not ours with our three meals a day. Insulin in excess is a hormone for times of need, not for times of continuous abundance. But this condition, known by the long and difficult name of hyperinsulinemia, remains largely unknown and for a long time undiagnosed [4]. Obviously, an index that would tell one what will be the insulin response when a certain food is eaten, is extremely useful. Therefore, the newer Insulin Index, the result of realizing that the Glycemic Index alone is not always a reliable guide to our foods and how we eat them.

The link with killer diseases

In addition, hyperinsulinemia and the ensuing insulin resistance are often found together, and both are closely linked with metabolic disorders and our current killer diseases, like obesity, heart disease, high blood pressure, stroke, diabetes, some forms of cancer, etc. In other words, the chronic degenerative diseases that are the hallmark of 20th century disease patterns.

Knowing the Glycemic Index and Insulin Index of foods, understanding what happens to our insulin secretions when various foods are eaten, why not to frequently eat mixed meals, inevitably leads to Nutrient Partition. But gently, not fanatically. An occasional mixed meal is no problem, provided we have stabilized our metabolism. In fact, this is the best test for a balanced metabolism: eating a meal that previously made you gain weight overnight, which now does not affect your weight-balance in any way. Problems begin when we make a habit out of what was the rarest exception for our ancestors, such as having three mixed meals a day. By contrast, nutrient partition helps balance our metabolism, which is the most important first step in recovering our health, and losing weight gradually, painlessly, and permanently.

Thus the Glycemic Index of foods together with the Insulin Index are very helpful tools in understanding and assessing the usefulness of carbohydrate foods and the corresponding insulin responce; but also of the problems arising when we mix starches with proteins on a continuous basis.


  1. Jenkins DJA, Wolever TMS, Taylor RH et al 1981. Glycemic index of foods. A physiological basis for carbohydrate exchange. American Journal of Clinical Nutrition 34:362-66.
  2. Foster-Powell K & Brand Miller J 1995. International tables of glycemic index. American Journal of Clinical Nutrition 62 (Suppl):871S-893S.
  3. Chew I, Brand JC, Thorburn AW, Truswell AS 1988. Applications of glycemic index to mixed meals. American Journal of Clinical Nutrition 47:53-56.
  4. Phillipson C & J 1998. A Testament of Savagery: The Folly of Balanced Meals. [The Road of Food Habits in the Mediterranean Area. 7th Meeting of the International Commission on the Anthropology of Food, Naples, May 26-30, 1997]. Rivista di Antropologia 76 (Suppl):283-292