Obesity Facts - Glycemic & Insulin Indices

Now, there are two indices in obesity facts, which I hope will start to help you to understand the importance of insulin in aiding weight loss, and its relationship to the types of foods we eat. These are the glycemic index and the insulin index. Of the two, the glycemic index has been around since the early 1980's having originally been developed by Dr. David Jenkins and colleagues in 1980–1981 at the University of Toronto in their research to find out which foods were best for people with diabetes. The insulin index was developed in the late 1990's by Dr Susannah Holt at the University of Sydney and in many ways is even more useful than the former, so let's take a look at both and see what information they provide to help us lose weight.

Obesity Facts - Glycemic Index

Not all carbohydrate foods are created equal, in fact they behave quite differently in our bodies. The glycemic index or GI describes this difference by ranking carbohydrates according to their effect on our blood glucose levels. Choosing low GI carbohydrates - the ones that produce only small fluctuations in our blood glucose and insulin levels - is the secret to long-term health, reducing your risk of heart disease and diabetes, and is the key to successful and sustainable weight loss. Now while this particular index has been used for many years, it is far from perfect, and my own view is that the insulin index is a far more useful and valuable measure. The GI methodology was developed to rank foods according to the extent to which they increase blood glucose concentrations, this being a useful guide to help those people with diabetes choose foods with lower glycemic responses. As we already know insulin promotes the uptake of glucose from general circulation, into the cells for use in energy production. Now in my view the index is an over simplification of the facts as follows :

1. Foods high in carbohydrate have higher GI's than protein rich foods

2. Fruits are high in sugar and therefore have higher GI's

3. A higher GI means the body must produce more insulin and therefore low GI foods are safer

In addition to the above inaccuracies, the GI index is based on a 50g serving ( not typical) and finally the index suggests that because protein rich foods produce a low blood glucose response, then it assumes that there is a  correspondingly low insulin response, which is simply not the case! So is the insulin index any more helpful in our obesity facts - let's take a look.

Obesity Facts - The Insulin Index

The Insulin Index is a measure used to quantify the typical insulin response to various foods. The index is similar to the GI, but rather than relying on blood glucose levels, it is based on blood insulin levels. This measure is far more useful to us than the GI, because certain foods such as lean meats and proteins can cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load. Now I would be the first to admit that this index is in the early stages, but as I keep saying, I am living proof that this works! Whilst there is a strong correlation between the GI and II indices, there are some startling differences,  where a food has a low glycemic value, but a high insulin index value. This applies to dairy foods and to some highly palatable energy-dense "indulgence foods." Some foods such as meat, fish, and eggs that contain no carbohydrate, just protein and fat (and essentially have a GI value of zero), can still stimulate significant rises in blood insulin, which is one of the reasons you will struggle to lose weight, until you become an 'insulin convert' like me!! As an example of this on a personal basis, I find it very difficult to lose weight when eating lean red meat, whilst as soon as I change to a fish regime such as salmon or tinned sardines, weight loss continues.

Now in order to try to put this into context for you, I have reproduced a table which compares one index with the other - there are some surprising differences as you will see. The values are based on white bread having a value of 100.

And you thought you were going to lose weight eating yoghurt and crackers - I think not!! I hope the above has helped to put into context some of the issues regarding weight loss and in particular the insulin effect. I do accept that the above study was relatively limited, but I do believe it provides an infinitely better measure of which foods are more likely to produce a strong insulin response. Now let's look at sugar in obesity facts - the silent killer and single most common reason for obesity and the inability to lose weight. 

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