Understanding the various factors that affect your insulin requirement is critical to the management of diabetes and optimal health.
Living with someone who has Type 1 Diabetes for seventeen have given me an intimate appreciation of how different foods affect your blood glucose levels.
Poor food choices can send you on a blood glucose rollercoaster that can affect your appetite, mood and energy levels for many hours and even days.
Fortunately, the latest insulin index testing data can help us to manage our food choices and stabilise our blood sugars and insulin levels.
In this article, I will share my analysis, experience and insights into how we can use the insights from insulin index testing to optimise your metabolic health.
The blood glucose roller coaster
Since she was ten, my wife Monica has had to manually manage her blood sugars as they swing up with food and then drop again when she injects insulin. The continuous glucose monitor chart below shows a typical daily experience for someone with Type 1 Diabetes.
High blood glucose levels make her feel “yucky”. And then, the plummeting blood glucose levels due to the mega doses of insulin don’t feel good either.
Low blood glucose levels drive you to eat until you feel good again. This wild blood glucose roller coaster ride leaves you exhausted and often depressed. Watching your blood sugars go up and down on a continuous glucose meter can even make you afraid to eat because just about anything you eat will mess up your blood sugar levels.
Monica now has an insulin pump which means she doesn’t have to inject with an insulin syringe six times or more a day. But good blood glucose control still comes down to managing the food you eat. The stabilisation of the swings in blood sugars requires intelligent food choices to manage the insulin load of the food you eat.
The dietary advice that Monica has someone with Type 1 has been sketchy at best. When she was first diagnosed with Type 1, she tells the story of being told to eat so much high carb food that she hid it in the pot plants in her hospital room.
These days the story is pretty much the same. The photo below of Lucy Smith, a young friend of ours, in the hospital just after she was diagnosed with Type 1 Diabetes.
Lots of carbs may stop you experiencing low blood sugar, but then you have to dose with insulin to try to get the blood sugars down. Then, because insulin and carbohydrates work at different rates, there is no way to stabilise blood sugar levels effectively.
When we decided we wanted to have kids, we found a fantastic doctor who helped us to understand how to match insulin with carbs. However, no one really told us how to make better food choices to reduce the amount of insulin required,.
We eventually stumbled across the online low carb community. Since then, Monica has been able to improve her blood glucose control significantly . This has enabled her to have a lot more energy to invest in to being a mother as well as going back to work as a teacher which she loves.
Low carb produces excellent results for people trying to stabilise their blood sugars. But there is still more to the story for people who need to manage the insulin they are injecting.
The latest food insulin index data
In early 2014 I learned about the insulin index research that had been carried out at predominantly the University of Sydney. The goal of this research was to provide more insight into our insulin response to food.
I hoped that by gaining a better understanding of how different foods affect our requirement for insulin that I might be able to help further optimise our food to normalise Monica’s blood glucose swings.
Unfortunately, while the concept of insulin index testing is exciting, the data that is commonly available is hard to make sense of. The initial research into the food insulin index was detailed in a 1997 paper An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods by Susanne Holt, Jennie Brand-Miller and Peter Petocz who tested the insulin response to thirty-eight different foods. The insulin score of the various foods tested is shown in the image below.
The food insulin index score of various foods was determined by feeding 1000kJ (or 239 kcal) of a range of foods to non-diabetic participants and measuring their insulin response over three hours. Some example responses to different foods are shown in the chart below
This value is then compared to the insulin response to pure glucose (which is assigned a value of 100%) to arrive at a “food insulin index” value for each food. All foods tested were then ranked relative to pure glucose.
Considering how significant this information could be for people trying to manage their insulin levels I was surprised that there hadn’t been a lot of further research or discussion on the topic. I found a few references and mentions in podcasts, but no one was quite sure what to do with the information. The chart showing the insulin index of the original 38 foods tested was really more confusing than useful for most people.
But then I found the mother load of data!
But then, after searching some more, I came across a PhD thesis Clinical Application of the Food Insulin Index to Diabetes Mellitus (Kirstine Bell, September 2014). Appendix 3 of the thesis contained an extensive food insulin index database of foods that had now been tested. The figure below shows all the foods tested plotted from smallest to largest insulin response.
[I know this is a bit hard to read. You can click on the image to expand it. I’ve also uploaded these charts to Tableau online here so you can make more sense of the data.]
The chart below shows the relationship between carbohydrates and insulin response for all the foods tested to date.
As you can see, the relationship between the carbohydrates we eat and the insulin we require to metabolise our food is not straightforward.
Some high protein and low-fat foods (e.g. fish and steak) are sitting quite high up on the vertical axis while there are some high fibre foods (e.g. all bran and navy beans) and high fructose foods (e.g. raisins and apples) with a lower insulin response than you might expect.
However, once we account for the effect of protein, fibre we are able to more accurately predict our body’s insulin response to food. The foods in the bottom left corner of this chart will require the least insulin (e.g. butter, olive oil and avocado) while the foods in the top right will need the most insulin (e.g. rice bubbles, cornflakes and jellybeans).
It’s also interesting to note that fructose (a form of sugar found in fruit) requires only about 25% as much insulin as glucose. The glycerol backbone in fat can also be converted to glucose via gluconeogenesis if there is no other glucose available from glucose or protein in the diet. However, neither of these have a massive influence compared to carbohydrates, protein and fibre.
How is this useful?
This improved ability to quantify our insulin response to food enables us to precisely identify foods that require less insulin and reduce the amplitude of our blood sugar swings in response to food.
Many people trying to follow a therapeutic ketogenic diet (for the management of cancer, epilepsy, Alzheimers, dementia etc.) have found it very useful to reduce their insulin requirements and increase their ketone levels.
Similarly, people with diabetes who are injecting insulin have also found it to be invaluable to help them more accurately. See How to Calculate Insulin Dosing for Type 1 Diabetes (Including Protein and Fibre) for more details.
Calculating the proportion of insulinogenic calories is useful for people who require a very low insulin therapeutic ketogenic diet while insulin load is useful for people managing hyperinsulinemia, insulin resistance or diabetes (see Insulin dosing for Type 1 Diabetes article)
Monica’s daily insulin dose has dropped from more than fifty units a day to closer to 20 units of insulin per day, and the amplitude of her blood glucose swings is much smaller. The improvement in the quality of life, energy levels and mood for someone with diabetes when they stabilise their blood sugars is massive.
Limitations of the food insulin index
The problem with looking at things purely from a food insulin index perspective is that the resultant high-fat foods do not provide a broad range of micronutrients. A diet with a low proportion of insulinogenic calories also tends to be very energy dense which can make portion control more challenging for people wanting to lose weight.
Many people have interpreted the insulin index data as an indication that protein turns into sugar in the bloodstream and should, therefore, be avoided. The reality is more complex than that. If your pancreas is working well then it’s likely that protein will cause your blood sugars to go down. If you see your blood sugars rise after a high protein then it may be because your pancreas cannot produce enough insulin to metabolise the protein and keep blood sugars stable at the same time. While there is no need for someone in this situation to go overboard with protein, it may be better to look at adding extra insulin rather than avoiding protein. Check out Why Do My Blood Sugars Rise after a High Protein Meal for more details.
While stabilising short-term glucose swings is related mainly to the quality of the food we eat, bringing down the overall blood sugar and insulin level down is mostly about weight loss and the quantity of food we eat.
The food insulin index testing was carried out over only three hours so it really only shows how our insulin requirements respond over the short term. Over the longer term, it seems that the insulin demand of our food is proportional to the energy in the food we eat. I encourage you to read The Carbohydrate Insulin Hypothesis vs the Adipose Centric Model of Diabetes and Obesity if you ware interested in managing your blood sugars and optimising your body composition with diet.
Once we stabilise blood sugars with a lower insulin load diet, we then need to focus on reducing the energy density of your food to enable you to lose weight and allow then fat stores to function optimally.
Diabetes occurs when our fat stores become too full, and they can no longer expand and contract to absorb and release the food from our meals, and the excess energy spills into the bloodstream. Increasing the nutrient:energy ratio of our food will allow us to get the nutrients we need with less energy which will, in turn, help us to achieve and maintain an optimal body fat level.
optimal foods for different goals
This refined understanding of how to calculate our insulin response to food is a useful parameter, along with nutrient density and energy density, which enables us to prioritise our food choices to suit different goals.
Building on the ability to quantify insulin load, nutrient density and energy density, more recently I have been developing an exciting new tool. The Nutrient Optimiser reviews your food log diet and helps you to normalise your blood glucose and insulin levels by gradually retraining your eating habits by eliminating foods that boost your insulin level and blood glucose levels using our ability to calculate the insulin load.
As shown in the chart below, some nutrients are easy to find. However, most of us have a large number of micronutrient gaps and need to prioritise the foods and meals that will provide those harder to find nutrients. Once your glucose levels are normalised, the Nutrient Optimiser will help you to focus more on getting the nutrients you need.
Then, if you still have weight to lose, the Nutrient Optimiser will focus on the energy density of your diet until you have achieved your desired level of weight loss.
It’s early days for the Nutrient Optimiser, but the initial results are very promising. I’d love it if you’d head over to NutrientOptimiser.com to get your free report to find your optimal dietary approach and which foods, meals will be ideal for you.
Post last updated June 2018