Optimising Nutrition

How to harness the power of the insulin index of foods

The Insulin Index Of Foods is a powerful tool that can help you understand which foods raise insulin levels more than others.  This enables you to make wiser dietary choices to maintain stable blood sugar levels.[2] [3]

The insulin index food chart below shows the results of the insulin index testing (from An Insulin Index of Foods:  the insulin demand generated by 1000 kJ portions of common foods, Holt et al., 1997).  Jelly beans are the most insulinogenic, while foods like eggs, butter, bacon and olive oil require less insulin.

Which foods raise insulin the most?

Since the original 1997 testing, the database of foods has been expanded to contain more than one hundred foods.  This enables us to understand how our food choices affect our insulin response to the food we eat.

While processed carbohydrates tend to raise insulin the most, foods with more protein (e.g. fish, steak and cheese shown to the far left of the chart below) also raise insulin significantly (check out the interactive Tabluea version of this chart here).

We can more accurately calculate the short term insulin demand of the food we eat once we account for the insulinogenic effect of protein.[4] [5]

Accounting for fat, fibre and fructose

Looking further into the data, we also see that:

We are able to more accurately predict our insulin response to food once when we consider the insulinogenic effects of fat, fructose and fibre (see the interactive version here).

This refined understanding of our insulin response enables us to:

Does protein increase insulin?

While protein does elicit an insulin response, foods with more protein tend to require less insulin because they contain fewer carbohydrates (see interactive Tableau version here).

Which amino acids are glucogenic?

As shown in the table below, most of the amino acids can be converted to glucose (via gluconeogenesis) if there is not a lot of carbohydrates available in your diet.

But unless you are injecting insulin to maintain stable blood sugar levels, you probably don’t need to worry about gluconeogenesis or excess protein overflowing into your bloodstream as glucose.

Gluconeogenesis is a highly energy-intensive process, and your body would much rather get its energy from fat or carbs than protein.

We lose about 25% of the energy from the protein we eat in the conversion to ATP to be used in our cells.  By comparison, we only lose about 8% of the energy from carbohydrates and 3% of the energy from fat.[8] [9] [10]

So, although protein can be used for energy, your body would much rather not have to convert protein to energy.  Hence, you will get a powerful satiety response when you have consumed enough protein.

What does insulin actually do?

While we often think of insulin as an anabolic hormone (to build things up), it can be much more helpful to think of insulin as anti-catabolic (to stop your body from falling apart).[11] [12]

The body uses insulin as a brake to control the flow of energy from storage (via the liver) when there is plenty of food coming in from your diet.

When there is less energy available from food, glucagon stimulates the release of stored energy and balances the effects of insulin.

When you consume more protein than you need for essential bodily functions (muscle protein synthesis, neurotransmitters etc.), your pancreas will raise insulin to shut off the release of stored fuel from your body while you use up the food coming in from our diet.

Although fat doesn’t require as much insulin, all foods trigger an insulin response over the longer term.

Note:  It’s important to keep in mind that the food insulin index testing was only over three hours, so it may underestimate the insulin response from protein which elicits a rise over eight hours or so while fat raises insulin for much longer.

Our insulin response to the different macronutrients seems to be proportional to their oxidative priority how easy they are to keep in storage and how much storage capacity we have for each of them.

We only have limited space to store carbohydrate.  It has to be burned off quickly, so the body raises insulin sharply to hold back your glycogen and adipose tissue in storage.  Any excess protein needs to be burned off fairly quickly, so we get a lower insulin response.

However, fat is easy to, store so we get a much smaller insulin response to fat over a more extended period.   What this means in practice is that, while consuming a diet with more fat is helpful if you are trying to stabilise blood sugar and insulin doses, it is not necessarily optimal if you are trying to lose body fat.

Does protein raise blood sugar?

As a general rule, consuming a higher percentage of protein will lower your blood glucose because it drives satiety and decreases the highly-processed carbs from your diet (see interactive version of this chart here).[13]

When you eat protein, you release both glucagon and insulin.  In most people, insulin and glucagon are balanced, so your blood sugars remain stable after a high protein meal.

But if you are insulin resistant, this signal becomes imbalanced and leads to a more dominant glucogen response from the liver and some elevation of blood sugars.[14]

If you are injecting insulin, you may need to top up with some extra so you can metabolise the protein to repair your muscles while also keeping your blood sugars stable.

Increasing the percentage of protein in your diet tends to lower your overall energy intake and hence reduce your body fat levels.  This, in turn, will lower basal insulin requirements (i.e. the insulin that you need when you are not eating) because you have less body fat to try to keep in storage.

A nutrient-dense diet tends to contain plenty of protein.  So, unless you require a therapeutic ketogenic diet (for the management of Alzheimer’s, dementia, Parkinsons or epilepsy), there is no need for most people to worry about eating “too much protein”.

For people with a functioning pancreas (i.e. you are not injecting insulin), focusing on reducing carbohydrates should be adequate to stabilise blood sugar levels. [15]

Insulin response to fat

Higher fat foods tend to cause a smaller insulin response.  However, there is still some insulin response (even over the first three hours) (see interactive Tableau version of this chart here).

Fat is the last macronutrient to be burned (after alcohol, ketones, excess protein and carbohydrate).  Fat is easily converted to energy or stored, so only a small amount of insulin is required to store any fat that is left over.

Some people like to believe that they can lower the insulin load of their diet to lose weight (a bit like someone with uncontrolled type 1 diabetes).

However, insulin is not only released in response to the food we eat (i.e. bolus insulin), but basal insulin is also required to keep the energy stored in our fat and muscles from leaching into the bloodstream.

If you are making your own insulin, your pancreas will not produce any more insulin than is required to hold your fat in storage while you use up the energy coming in from your mouth.

The more body fat you have, the more insulin will be required to keep our body fat locked away in storage.  This is why many people who are obese also have high fasting insulin levels.   It is not that insulin is causing them to be fat but rather that their pancreas is working overtime to keep insulin high to hold their fat in storage.[16] [17]

If your goal is fat loss, then you need to find a way of eating that allows you to be satisfied with less energy.  Your fasting insulin levels will reduce as your body fat levels decrease.[18]

Benefits of the insulin index of food

Insulin index for therapeutic ketosis

Many people with Alzheimer’s, epilepsy, dementia or Parkinson’s do well on a therapeutic ketogenic diet.

Ketones can supply much-needed fuel to the brain when glucose can no longer be used effectively due to insulin resistance that can develop after years of a poor diet.

Titrating down the insulin load of your diet to low levels can help to provide fuel to the brain for people who have become insulin resistant.

Diabetes

Understanding how much insulin is required for different foods is essential for people who are injecting insulin or taking diabetes medications (i.e. people with Type 1 or Type 2 diabetes).

It is impossible to perfectly match injected insulin with food.  The larger the dose of exogenous insulin, the larger the errors you make due to a wide range of factors such as insulin absorption, inaccurate food labelling and measurement.

A highly insulinogenic diet will leave you on a blood sugar roller coaster all day and feeling hangry.  It can also leave you feeling very fatigued and wreak havoc on your emotions.

Foods that require less insulin help stabilise blood sugars.  Less variation in blood sugars allows better control and lower blood sugars overall.  Dr Richard Bernstein calls this “The Law of Small Numbers”.

People injecting insulin will benefit from considering the insulin required for protein when calculating their insulin dose.  Improved blood sugar control can be achieved by titrating down the insulin load of your diet.

Many people find that they can signficantly reduce or eliminate their diabetes medications once they lower the insulin demand of their food to the point that their pancreas can keep up (see Guess what happened to body fat, lean mass and waist measurements when a hundred people tried the Nutrient Optimiser?)

Insulin Index for Fat loss

Some people think that ketosis is synonymous with burning fat from their body and weight loss, but it is not that simple.  Unfortunately, our modern food environment is set up to encourage us to buy and eat more food.  By contrast, whole foods are mainly carbs or fat+protein depending on the season and latitude.

Given the opportunity, we gravitate towards foods that are a mix of fat and carbs that enable us to fill up our glucose and fat stores at the same time.  this leads us to be able to store and consume a lot more energy.  This process also gives us massive dopamine hit that drives us to keep eating these foods.

Removing processed carbs from your diet and not fearing fat typically leads to improved appetite control.

The chart below shows satiety response versus carbohydrates, indicating that it’s the foods that are a mix of fat and carbs that tend to be the easiest to overeat, while less processed foods that are lower or higher carb tend to be harder to overconsume (see Systematising Satiety).

There seems to be a “sweet spot” when we consume between 20 to 30% carbs.  Hoever, very low carb diets can end up being high levels of dietary fat which can have an adverse effect on satiety.

Unfortunately, some people end up fatter and more insulin resistant after pursuing high blood ketone levels with lots of added fat and ketogenic foods.  “Fat to satiety” doesn’t seem to work when we consume refined fat with minimal protein.

If your goal is fat loss, there is no need to go out of your way to consume high-fat foods.  You will produce plenty of ketones as you burn your stored body fat!  As you get better at fat burning, especially fat from your body, you wll likely see your blood ketone values decrease as they continue to lose weight and improve their metabolic health.

The vast majority of the benefits of a ketogenic diet occur when ketones are coming from burning your body fat (endogenous ketosis) rather than from your dietary fat (exogenous ketosis).

Once you have stabilised your blood glucose levels with reduced carbohydrate intake, the next step on the weight loss journey is to focus on foods that maximise satiety (i.e. less starch+fat and more protein+fibre).

The chart below shows a plot of the satiety score vs insulin load.  While high-fat ketogenic foods are more satiating than highly processed junk food, if your goal is fat loss, you will benefit from progressing to more satiating whole foods towards the right on this chart (check the interactive version of this chart here).

Limitations of the Food Insulin Index

One of the most significant limitations of the insulin index data is that it only considers the short term insulin and blood sugar response to food (i.e. over the first three hours after eating).

The reality is that a large high fat meal can take a lot longer than three hours to digest and metabolise.  So it is likely that the Food Insulin Index data does not fully account for the long-term effect of protein or fat.

Insulin Index and Satiety

Reducing carbs and moving away from a highly processed diet will improve satiety and reduce hunger.  However, in time, you may also need to focus on reducing dietary fat to improve satiety even more and continue your fat loss journey.

A nutrient-dense diet also tends to be a high satiety diet, meaning you will be able to get the nutrients you need with fewer calories which will, in turn, lead to lower levels of body fat and insulin requirements.

You don’t need to worry if your blood ketones decrease as you approach your goal weight.  Metabolically healthy people tend to have lower levels of energy floating around in their blood (i.e. blood sugar, blood ketones, and free fatty acids) as well as lower body fat levels.[19]

Effects of low insulin index foods on nutrient density

Unfortunately, a high fat ketogenic diet can limit the amount of vitamins and minerals per calorie (aka nutrient density) in your food.

If you require a therapeutic ketogenic diet, you should pay extra attention to ensuring you get more of the harder to find vitamins and minerals in your diet.

The chart below shows that a highly ketogenic diet will also contain lower levels of vitamin A, choline, folate, potassium, calcium and omega 3.

By contrast, the chart below shows the micronutrients contained in the most nutrient-dense selection of foods.

The Nutrient Optimiser

To help you harness the power of the Food Insulin Index we have developed the Nutrient Optimiser to help you identify the foods and meals that will help you stabilise your blood sugars and achieve nutritional ketosis or a therapeutic levels of ketosis (if required).

You can start out with the Nutrient Optimiser Free Report, which will give you target macro ranges to suit your goals along with some recommended foods and meals.  From there, the Nutrient Optimiser will guide you to help you dial in your blood sugars, weight and body fat levels to ensure you achieve your goals.

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