Insulin index

The Insulin Index is a measure used to quantify the typical insulin response to various foods. The index is similar to the Glycemic Index and Glycemic Load, but rather than relying on blood glucose levels, the Insulin Index is based upon blood insulin levels. This measure can be more useful than either the Glycemic Index or the Glycemic Load because certain foods (e.g., lean meats and proteins) cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load.

Holt et al. have noted that the glucose and insulin scores of most foods are highly correlated, but high-protein foods and bakery products that are rich in fat and refined carbohydrates "elicit insulin responses that were disproportionately higher than their glycemic responses." They also conclude that insulin indices may be useful for dietary management and avoidance of non-insulin-dependent diabetes mellitus and hyperlipidemia.

Explanation of Index
The insulin index shows how much insulin is present in people's blood as a result of a particular food, the glucose index shows how much glucose is present in the blood as a result of a particular food, and the satiety index shows how much a particular food decreases one's propensity to eat more.

Glucose (glycemic) and insulin scores were determined by feeding 1000 kilojoules (239 kilocalories) of the food to the participants and recording the area under the glucose/insulin curve for 120 minutes then dividing by the area under the glucose/insulin curve for white bread. The result being that all scores are relative to white bread. The satiety score was determined by comparing how much food was eaten by participants at a buffet after being fed a fixed number of calories of a particular food while blindfolded (to ensure food appearance was not a factor), then dividing that number by the amount eaten by participants after eating white bread. White bread serves as the baseline of 100. In other words, foods scoring higher than 100 are more satisfying than white bread and those under 100 are less satisfying.

+/- indicate uncertainty in the data. For example 60 +/- 12 means that there's a 95% chance the score is between 60-12 (48) and 60+12 (72), 60 being the highest probability assuming a bell curve. In practice this means that if two foods have large uncertainty and have values close together then you don't really know which score is the higher.

Something to note: the authors of the satiety study stated that the amount of jellybeans consumed tended to make participants nauseous which may have produced an erroneous satiety score.

The research was supported by grants from The University of Sydney and Kellogg's Australia Pty Ltd.