Article written by Dr. Fiona McCulloch, ND, author of 8 Steps to Reverse Your PCOS. Fellowship-trained in naturopathic endocrinology. Developer of the clinic’s insulin-management nutrition program based on Food Insulin Demand research.
Food Insulin Demand & the Insulin Index: A Practical Guide for PCOS and Metabolic Health
Insulin resistance is central to PCOS — but most dietary advice stops at “cut carbs.” The insulin index reveals something that surprises many people: some protein-rich foods spike insulin as much as bread, or more. This page explains the science behind the insulin index and food insulin demand, provides a portion-adjusted food comparison table, and shows how Dr. Fiona McCulloch has translated this research into a simplified nutrition approach used clinically for PCOS at White Lotus Clinic.
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 — 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 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.
Many women with PCOS describe a familiar cycle: trying restriction-based diets, losing some weight — or sometimes not — and watching it return the moment the approach becomes too difficult to sustain. If this sounds familiar, it’s worth understanding that the challenge is not about willpower. It’s about how specific foods affect insulin, satiety, and blood sugar regulation in PCOS — and why approaches designed for the general population often don’t account for these patterns. The science below helps explain why.
The Insulin Index
You’ve likely heard of the glycemic index, which measures how much a food raises blood sugar levels. The insulin index goes further — it tells us 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 increased 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 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 relevant to insulin resistance and type 2 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 very low on the glycemic index and don’t raise blood sugar levels much at all.
Dairy Proteins
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. Cottage cheese and whey protein powder are also among the highest foods on the insulin index — despite being low-glycemic. Dairy proteins can spike insulin more than other protein sources.
Meat and Other Proteins
Some protein-rich foods may surprise you as well — beef spikes insulin levels more than chicken. However, protein still plays an important role in nutrition because it increases satiety and also causes glucagon release, which counters the spike of insulin.
Refined Carbohydrates
Bread, rice, muffins, and pancakes trigger significant insulin release as expected — but the food insulin demand values below put these in perspective alongside proteins and dairy, adjusted for the portions we actually eat.
Food Insulin Demand
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 — making it an exceptionally useful tool for evaluating meals. FID is to the insulin index as the glycemic load is to the glycemic index — it gives us quantity information, but it also accounts for the fact that proteins raise insulin.
In her book 8 Steps To Reverse Your PCOS, Dr. Fiona McCulloch includes an easy-to-follow system based on the food insulin demand created at the University of Sydney. The approach includes a structured plan with a lower insulin count for breakfast — when insulin sensitivity is at its best — and individually determined counts 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 on 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.
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.
Sample Foods and Their Insulin Demand
| Food | Quantity | Food Insulin Demand |
|---|---|---|
| Proteins | ||
| Chicken | 130 grams | 20 |
| Grilled Lean Beef Steak | 130 grams | 30 |
| White Fish | 130 grams | 17 |
| Poached Eggs | 2 large | 14 |
| Shrimp | 7 shrimp | 4 |
| Navy Beans | 1 cup | 22 |
| Carbohydrates | ||
| White Bread | 2 slices | 53 |
| White Rice | 1 cup | 46 |
| Sweet Potato | 1 small (120g) | 37 |
| Butternut Squash | ½ cup (102g) | 18 |
| Low Fat Blueberry Muffin | 1 muffin | 116 |
| Pancake | 100 gram pancake | 83 |
| Dairy | ||
| Low Fat Fruit Yogurt | 175 gram container | 57 |
| Low Fat Cottage Cheese (2.5% fat) | 1 cup (240g) | 42 |
| Skim Milk | 1 cup | 23 |
| Fats & Nuts | ||
| Avocado | ¼ | 2 |
| Olive or Coconut Oil ** | 1 tbsp | 2 |
| Walnuts | ¼ cup | 4 |
| Almond Butter ** | 1 tbsp | 2 |
| Fruits | ||
| Banana | 1 small banana (104g) | 23 |
| Orange | 1 medium | 11 |
| Apple | 1 medium | 15 |
| Berries ** | 1 cup | 3 |
| Vegetables | ||
| 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. | ||
How Food Insulin Demand is Calculated
You may notice that the FID values in the table above differ from the insulin index numbers posted on Wikipedia. That’s because FID and the insulin index are related but distinct measures. The insulin index is based on consuming 240 calories (1000 kJ) of a food — regardless of how much food that represents. FID adjusts for the quantity you would actually eat.
FID = energy of the food (kJ) × FII / 1000 kJ
Or: FID = energy of the food (calories) × FII / 239 calories
For example, a banana has an insulin index (FII) of 59 on the updated glucose-scaled index. One small banana contains roughly 360 calories worth of energy in kilojoules. So: FID = 360 × 59 / 1000 ≈ 21 — close to the listed value of 23 in the table above. The slight difference reflects variation in banana size and the rounding inherent in these calculations.
Note that the Wikipedia article uses the original 1997 index scaled to white bread, where bananas are listed at 81. The updated index, scaled to glucose (consistent with the modern glycemic index), lists bananas at 59. The FID values in the table above use the updated scale. For more detail, see Dr. Kirstine Bell’s PhD thesis on the clinical application of the insulin index from the University of Sydney.
From FID Research to a Simplified Nutrition Approach
The food insulin demand research is sound — and for those who find the science interesting, the table above provides a genuinely useful reference. But over years of clinical practice, Dr. Fiona found that the FID table was too detailed for most patients to apply independently in daily life. Not enough foods have been tested, and the research hasn’t expanded significantly since her book was published. Rather than asking patients to track FID numbers, she incorporated the underlying principles into a simplified macro-based nutrition system — one that captures the clinical essence of FID without the complexity.
The nutrition approach used at White Lotus Clinic for PCOS is built on concepts that patients can learn and follow long-term:
- Work with your body’s morning insulin sensitivity. Insulin sensitivity is at its highest earlier in the day — the approach takes advantage of this natural pattern rather than fighting it.
- Stabilize blood sugar by combining macros at each meal. Rather than focusing on a single nutrient, combining proteins, fats, and carbohydrates at each meal helps maintain steady blood sugar throughout the day.
- Cycle carbohydrates strategically — don’t eliminate them. This is not a low-carb diet. Carbohydrates are included with intention, adjusted based on timing and context.
- Include all favourite foods. This approach is explicitly not about restriction. The foods you enjoy are part of the plan — because sustainability requires it.
- Focus on long-term consistency over short-term perfection. The goal is a system that is doable for people — not another approach that works for a few weeks and then becomes impossible to maintain.
These simple concepts capture the clinical essence of the FID research — including the insight that proteins and dairy affect insulin — without requiring you to calculate anything.
You may have noticed that the table above shows protein spiking insulin — so should you avoid it? No. Protein is still prioritized in this approach because it increases satiety and causes glucagon release, which counters the insulin spike. Dairy proteins spike insulin more than other proteins, which may be relevant for certain patients, but overall protein remains a foundation of the nutrition strategy. This is the kind of clinical nuance that a simplified system accounts for.
For a structured clinical program applying these principles with individualized dietary planning and metabolic assessment:
Common Questions About Food Insulin Demand and PCOS
What foods spike insulin the most?
The foods that produce the highest insulin response include refined carbohydrates (a low fat blueberry muffin has a food insulin demand of 116, pancakes score 83), dairy products (low fat yogurt at 57 — more than two slices of white bread at 53), and some proteins (grilled beef at 30 vs. chicken at 20). The surprise for many people is that some low-glycemic foods, particularly dairy, spike insulin significantly. The food insulin demand table above shows portion-adjusted values for 26 common foods. For more on dietary considerations specific to PCOS, see our dedicated guide.
What is the difference between the insulin index and the glycemic index?
The glycemic index measures how much a food raises blood sugar. The insulin index measures how much a food raises insulin — and these don’t always match. Some low-glycemic foods, especially dairy and certain proteins, spike insulin significantly without raising blood sugar much at all. Food insulin demand (FID) goes one step further by adjusting the insulin index for real-world portion sizes, similar to how glycemic load adjusts the glycemic index.
Is Food Insulin Demand the same as a low-carb diet?
No. Low carb involves restricting the quantity of carbohydrate — it’s a dietary approach. Food insulin demand is a metric that measures how much insulin is released when a specific food is consumed in a given quantity. FID captures information about protein and dairy insulin responses that carbohydrate-only approaches miss entirely. The nutrition approach used at White Lotus Clinic incorporates cycled carbohydrates and macro combining informed by FID research — it includes carbohydrates strategically rather than eliminating them. The result is an approach that can be sustained long-term because it doesn’t rely on restriction.
Does insulin resistance cause PCOS?
Insulin resistance doesn’t cause PCOS, but it’s a major driver of symptoms in many PCOS types. When insulin is elevated, the ovaries in women with PCOS overproduce testosterone — leading to irregular cycles, weight gain, acne, and hair changes. Not all women with PCOS have insulin resistance, and women without PCOS can be insulin resistant with completely normal androgens. PCOS is caused by a combination of genetic predisposition and environmental factors. Understanding your specific pattern — including whether insulin resistance is a significant factor — is part of a thorough PCOS assessment.
Why does yogurt spike insulin more than bread?
Dairy contains branched-chain amino acids that enter the bloodstream rapidly and trigger a surge of insulin release — completely separate from any blood sugar effect. This is why low fat yogurt (FID: 57) provokes a stronger insulin response than two slices of white bread (FID: 53), despite being low on the glycemic index. The same mechanism explains the high insulin response to cottage cheese and whey protein.
How is Food Insulin Demand used in PCOS treatment?
Food insulin demand is one of the nutritional frameworks used in PCOS assessment at White Lotus Clinic. Over years of clinical practice, Dr. Fiona McCulloch incorporated the FID research into a simplified macro-based nutrition system — patients learn practical principles rather than tracking FID numbers directly. The approach is personalized by PCOS type: for insulin-resistant types, insulin management through nutrition is a critical part of assessment; for non-insulin-resistant types, the emphasis shifts to blood sugar stabilization. Nutrition is prescribed alongside other approaches including inositol and metformin and berberine, because insulin resistance is a physiologic hormonal process — not solely a dietary one.
Food Insulin Demand and PCOS: Why Your Type Matters
Insulin-Resistant PCOS
For women with significant insulin resistance — the most common PCOS presentation — managing insulin through nutrition is a critical part of assessment and care. Elevated insulin stimulates the ovaries to overproduce androgens, driving the cycle irregularity, weight gain, acne, and hair changes that define many women’s experience of PCOS. The macro-based nutrition system used at the clinic directly addresses this mechanism: working with morning insulin sensitivity, stabilizing blood sugar through macro combining, and cycling carbohydrates to manage insulin responses throughout the day.
Lean, Adrenal, and Non-Insulin-Resistant PCOS
Food insulin demand principles can be relevant for non-insulin-resistant PCOS types as well, though the emphasis shifts. For these patients, the focus is less on insulin management and more on stabilizing blood sugar to prevent stress responses and hypoglycemia. Blood sugar instability can trigger cortisol and adrenaline release, which affects adrenal androgen production through a different pathway. The same core principles — macro combining, strategic carbohydrate timing, and avoiding prolonged restriction — apply, but are adapted based on individual assessment of PCOS type and metabolic patterns.
Nutrition is the most important factor for many patients with manageable insulin resistance, but it is prescribed alongside other approaches. Because insulin resistance is a physiologic hormonal process — not solely a dietary problem — supplements for insulin resistance, including berberine and inositol, can support the nutritional strategy as part of a comprehensive assessment.
Insulin resistance can worsen during perimenopause as hormonal shifts — particularly declining estrogen and changing progesterone patterns — affect metabolic function. Women with PCOS who have managed their insulin resistance for years may notice changes in their late 30s or 40s. Understanding how food affects insulin becomes especially relevant during this transition.
PCOS and perimenopause → | Menopause and perimenopause program →
What a Sustainable Approach Looks Like
Many patients find that understanding these principles shifts something fundamental in how they think about food and PCOS. Not another elimination diet — a nutrition approach that includes the foods you enjoy. Not a complex tracking system — simple concepts that can be followed long-term without detailed nutritional knowledge.
The reframe patients often describe learning: it’s not about eating too much. It’s about how specific foods interact with your body’s insulin patterns — and once you understand a few basic principles, the approach becomes something you can sustain. Not perfect adherence, but long-term consistency. Not restriction, but awareness. For many, that shift — from “I have to give things up” to “I understand how to work with my body” — is what makes the difference between an approach that lasts weeks and one that lasts years.
The Research Behind Food Insulin Demand
The insulin index was developed at the University of Sydney by Dr. Jennie Brand-Miller and her team — the same researchers behind the glycemic index. The foundational paper was published in the American Journal of Clinical Nutrition in 1997 with 38 foods. Dr. Kirstine Bell’s 2014 PhD thesis expanded the tested food list to 147 items and explored the clinical application of insulin indexing. Food insulin demand is the practical extension — adjusting the insulin index for real-world portion sizes, similar to how glycemic load extends the glycemic index.
It’s worth being transparent about what FID can and can’t do. The tested food list remains limited — roughly 147 foods, with some values estimated based on composition rather than measured in human volunteers. The research hasn’t expanded significantly in recent years. FID is, as Dr. Fiona describes it, similar to glycemic load but with the added dimension that proteins raise insulin. These limitations are part of why the clinic incorporates FID principles into a broader macro-based strategy rather than using FID values alone — the science informs the approach, but the clinical system goes beyond what the published data can specify for every individual food.
How FID-Informed Nutrition Differs from Carbohydrate-Only Approaches
Low-carb diets involve restricting the quantity of carbohydrate. Food insulin demand is a measurement — a metric that tells you how much insulin is released when a specific food is consumed in a given quantity. These are fundamentally different things: one is a dietary approach, the other is a piece of information.
Understanding FID adds a dimension that carbohydrate-only approaches don’t capture: the insulin response to protein and dairy. A low-carb plan might encourage unlimited lean protein and yogurt, not accounting for the fact that these foods also spike insulin — sometimes significantly. FID makes this visible.
The nutrition approach used at White Lotus Clinic incorporates cycled carbohydrates and macro combining informed by FID research. It includes carbohydrates — strategically and with intention — rather than eliminating them. For patients with PCOS who have experienced the restriction cycle, this distinction matters: it’s an approach designed to be followed long-term, not abandoned after a few difficult weeks.
Meet our medical director, Dr. Fiona McCulloch, ND
- Fellow of the American Board of Naturopathic Endocrinology (FABNE)
- Author of 8 Steps to Reverse Your PCOS (Greenleaf Book Group, 2016)
- Peer reviewer, 2023 International Evidence-Based PCOS Guidelines
- 25+ years clinical focus in PCOS and hormonal health
- Developed White Lotus Clinic’s FID-informed nutrition program for PCOS
Dr. Fiona’s work with food insulin demand spans from the published research in her book to years of clinical refinement — evolving from the detailed FID table into the simplified macro-based approach patients use today. That clinical evolution, from academic research to practical patient care, is reflected in how the clinic approaches insulin-management nutrition.
If You're in Ontario
White Lotus Clinic is located in North York, Toronto, with virtual consultations available across Ontario. Dr. McCulloch’s team offers PCOS assessments that apply these nutrition principles to your specific PCOS pattern — without requiring you to track FID numbers yourself.
Our PCOS Program
White Lotus Clinic is located in North York, Toronto, with virtual consultations available across Ontario. Dr. McCulloch’s team offers PCOS assessments that apply these nutrition principles to your specific PCOS pattern — without requiring you to track FID numbers yourself.
The FID Weight Loss Program
A structured clinical program that applies FID-informed nutrition principles with individualized dietary planning, metabolic assessment, and ongoing support. Available for existing and new patients.
Related Resources
PCOS & Insulin Management
- Naturopathic care for PCOS — comprehensive PCOS assessment at White Lotus Clinic
- FID Weight Loss Program — structured clinical program applying FID-informed nutrition
- Supplements for insulin resistance — alongside dietary approaches
- Berberine for insulin-resistant PCOS — addressing root causes
- Inositol and metformin for insulin resistance — comparing options
- Foods to avoid with PCOS — dietary guidance
- How insulin affects PCOS fertility — the insulin-fertility connection
- How sleep affects insulin — the sleep-insulin relationship
Perimenopause & Metabolic Health
If you’re experiencing changes in your metabolic patterns during perimenopause:
- PCOS and perimenopause — how PCOS changes during the menopausal transition
- Menopause and perimenopause program — comprehensive support for hormonal transitions