PCOS includes distressing symptoms such as irregular menstrual cycles, weight gain, infertility, acne, hair loss and increased facial hair growth in women. Central to the condition is insulin resistance – although not every woman with PCOS suffers with insulin resistance, it affects the vast majority. In this article, I’ll begin to explain an easy-to-follow dietary method based on the insulin index of food which can help to manage insulin resistance in women with PCOS.
What Does Insulin Do?
Insulin is likely the most well-known hormone that rules our nutritional metabolism. Its main role is to direct the nutrients that we eat into our cells, where they can be stored as energy.
After we eat, our blood sugar levels rise and our pancreas responds by releasing insulin to shuttle the extra energy away. This keeps blood sugar under strict control. Insulin also blocks fat breakdown – after a meal our metabolisms are focused on storing energy, and not on burning fat.
Carbohydrates are well-known for spiking blood sugar levels, so it makes sense that they also cause significant insulin release. What many people don’t know is that some protein-rich foods can spike insulin levels just as much as carbohydrates, or even more.
What is Insulin Resistance?
Insulin resistance is a state where our cells become less sensitive to the actions of insulin. The pancreas makes more insulin to compensate as its main goal is to stop blood sugar levels from becoming too high. The end result is a whole lot more insulin floating around in the bloodstream. Insulin resistance happens naturally with weight gain, or if we have the genes that predispose us to it.
Signs of Insulin Resistance in Women
How do you know if you have insulin resistance? The most typical signs include abdominal weight gain and significant difficulty in losing weight. Weight loss resistance can happen as high levels of insulin block fat breakdown.
In women with PCOS, the ovaries overproduce testosterone when they are exposed to excess insulin. Excess testosterone slows down the development of the follicles, causing prolonged times before ovulation, irregular menstrual cycles and infertility as in more severe cases women can stop ovulating altogether.It’s important to know that high insulin levels aren’t the cause of PCOS – as insulin only stimulates the release of androgens in women with the condition. In women without PCOS – they can be insulin resistant and have completely normal androgens. PCOS is a condition which is caused by a mixture of genetic predisposition, and environmental factors.
When testosterone becomes overly abundant due to insulin resistance in PCOS, it can also affect a woman’s skin. Jawline cystic acne, hair loss, and excess facial or body hair growth are troubling testosterone-induced skin issues. Other skin-related signs of insulin resistance include skin tags, and dark pigmentation in the skin folds.
The Insulin Index
Before I go into deeper into the insulin counting method, it’s important to explain the underlying scale on which this is based, the insulin index. You’ve all likely heard of the glycemic index, which is a measure of how much a food we eat raises blood sugar levels. The insulin index does more – it tells us about how much a consumed food raises insulin levels. The first paper on the insulin index was published in the American Journal of Clinical Nutrition in 1997, with a list of just 38 foods. In 2011, the list expanded to include 120 foods. And in 2014 a thesis published by Dr. Kirstine Bell PhD on the clinical application of the insulin index was released increasing the number to 147 foods. Most information currently available on the insulin index is the result of years of work by esteemed researchers in nutrition for diabetes at the University of Sydney – Dr. Jennie Brand-Miller and her team.
This is the same team who worked to give us the majority of the information we currently know about the glycemic index. As a result, evidence for the insulin index sits atop many years of intensive research in nutrition in metabolic nutrition. Although most research on the clinical application of the insulin index has been focused on type 1 diabetes, it has now been found to be superior to current nutritional methods for insulin resistance and type two diabetes as well.
The insulin index does more – it tells us about how much a consumed food raises insulin levels. The first paper on the insulin index was published in the American Journal of Clinical Nutrition in 1997, with a list of just 38 foods. In 2011, the list expanded to include 120 foods. And in 2014 a thesis published by Dr. Kirstine Bell PhD on the clinical application of the insulin index was released increasing the number to 147 foods. Most information currently available on the insulin index is the result of years of work by esteemed researchers in nutrition for diabetes at the University of Sydney – Dr. Jennie Brand-Miller and her team. This is the exact same team who worked to give us the majority of the information we currently know about the glycemic index. As a result, evidence for the insulin index sits atop many years of intensive research in nutrition in metabolic nutrition. Although most research on the clinical application of the insulin index has been focused on type 1 diabetes, it has now been found to be superior to current nutritional methods for insulin resistance and type two diabetes as well.
Foods That Spike Insulin – Unlikely Culprits
Foods that are high on the glycemic index are also high on the insulin index – which comes as no surprise since insulin is released in response to increases in blood sugar.
The opposite isn’t true – in fact, some of the highest foods on the insulin index are in fact very low on the glycemic index, and don’t raise blood sugar levels much at all.
Dairy foods contain protein building blocks called branched-chain amino acids which enter the bloodstream rapidly and cause a surge of insulin release.
Most people are shocked to learn that low fat yogurt provokes more insulin release than two slices of white bread. Some other foods may surprise you as well – beef spikes insulin levels more than chicken, and whey protein powder is one of the highest foods on the insulin index.
The insulin index tells us how much insulin will be released for 240 calories of a food. The food insulin demand (FID), a related index, gives us the amount of insulin that we release after eating a certain quantity of a given food – an exceptionally useful tool we can use to plan meals.
Food Insulin Demand
In my book “8 Steps To Reverse Your PCOS“ I’ve included an easy-to-follow system based on the food insulin demand created at the University of Sydney. Insulin counting includes a structured lower-carbohydrate plan with a low insulin count for breakfast, and an individually determined count for lunch and dinner to manage post-meal insulin responses. The best foods and portion sizes are discussed in detail, creating an approach to lowering insulin that focuses around the consumption of quality, whole foods.
Although the jury is still out on the role of insulin in obesity – it’s clearly an aggravator to PCOS if secreted in excess as it causes androgen release from the ovaries. Although many who use the insulin counting method below will lose weight, there are definitely other approaches that are effective as well – however for PCOS, focusing on low insulinemic foods is something we’ve seen to be helpful clinically with our patients.
Below are the Food Insulin Demands of the most commonly consumed foods, healthy and otherwise, in the Standard American Diet.
Insulin demand is adjusted for quantity. For example, if you have 14 shrimp instead of 7, the count will double from 4 to 8.
|Food||Quantity||Food Insulin Demand|
|Grilled Lean Beef Steak||130 grams||30|
|White Fish||130 grams||17|
|Navy Beans||1 cup||22|
|Poached Eggs||2 large||14|
|White Bread||2 slices||53|
|White Rice||1 cup||46|
|Butternut Squash||1/2 cup (102g)||18|
|Sweet Potato||1 small (120g)||37|
|Low Fat Blueberry Muffin||1 muffin||116|
|Pancake||100 gram pancake||83|
|Low Fat Fruit Yogurt||175 gram container||57|
|Low Fat Cottage Cheese (2.5% fat)||1 cup (240g)||42|
|Skim Milk||1 cup||23|
|Olive or Coconut** oil||1 tbsp||2|
|Almond Butter **||1 tbsp||2|
|Banana||1 small banana (104 g)||23|
|Orange||1 medium –||11|
|Broccoli – steamed||1 cup (156g)||5|
|Cauliflower – steamed||1 cup (124g)||6|
|Leafy Green Vegetables||1 cup||0|
** These items have not yet been tested in human volunteers and are estimated based on composition.
I received the excellent question as to why these numbers are different than the Insulin Index which is posted on Wikipedia here. I will write a post on this but until then, here is why.
What I have based insulin counting on is the food insulin demand (FID), which although related to the insulin index, is a different index. FID is to the insulin index as the glycemic load is to the glycemic index – it gives us quantity information. For example – banana is quite high on the insulin index (banana has a FII of 59) as the insulin index is related to consuming 1000 kj/239 cal of bananas. Depending on the size, this could range from 2-3 bananas.
However when choosing a food to eat, it’s more useful to be able to measure according to the amount we would actually consume – one banana. The FID allows us to extrapolate the information in the insulin index to commonly consumed quantities.
To calculate the food insulin demand you can use the following equation.
FID = energy of the food (kj) x FII/1000kj
Or FID = energy of the food (calories) x FII/239 calories
Note that the Wikipedia article is using the original index from AJCN 1997 where the Insulin index was scaled to white bread. It has now been updated to be scaled to glucose similarly to the glycemic index.
In the insulin index on Wikipedia, the FII of bananas are listed at 81, whereas on the updated insulin index adjusted to glucose, bananas are listed at 59. So you would have to use the updated FII of 59 to use the equation for FID.
Check out this PhD thesis on the Clinical Application of the insulin index by the brilliant Dr. Kirstine Bell from the University of Sydney for more information, or feel free to post questions.