Insulin resistance affects up to 70% of women with PCOS, regardless of body weight, and it's one of the most common questions I get asked in consultations: "which foods should I avoid?" My honest answer is usually more nuanced than a simple avoid list — but there are some genuinely useful patterns worth understanding, and once clients grasp the "why" behind them, the changes tend to feel far more manageable than a restrictive rulebook.
Why Insulin Resistance Matters in PCOS
When your cells become less responsive to insulin, your body compensates by producing more of it. Higher circulating insulin levels can, in turn, stimulate the ovaries to produce more androgens, which can worsen symptoms like irregular cycles, acne and excess hair growth. This is why supporting insulin sensitivity through food is one of the most evidence-based nutrition strategies available for PCOS — it doesn't just affect blood sugar, it can influence the hormonal symptoms that often bring women to my clinic in the first place.
It's worth saying clearly: insulin resistance isn't something you caused, and it isn't something diet alone can "fix" overnight. It's a metabolic pattern that responds gradually to consistent changes, and progress is rarely linear. I always encourage clients to think in terms of weeks and months, not days.
Foods That Tend to Spike Blood Sugar Sharply
Rather than eliminating entire food groups, I encourage my clients to notice which foods cause the sharpest blood sugar spikes and pair or moderate them rather than avoid them outright:
- Refined carbohydrates eaten alone — white bread, white rice, and sugary cereals cause a faster rise in blood sugar, particularly on an empty stomach. Pairing them with protein, fibre or healthy fat softens this response considerably.
- Sugary drinks — fruit juice, sugary tea and soft drinks deliver a large amount of fast-absorbing sugar with very little to slow it down. Whole fruit is a better choice, as the fibre slows absorption.
- Highly processed snack foods — these are often low in fibre and protein, meaning less to buffer the blood sugar response, and are easy to overeat past the point of fullness.
- Large portions of starchy carbohydrates at once — even wholegrain carbohydrates can spike blood sugar if the portion is large and eaten without protein or fat alongside it.
What to Build Meals Around Instead
Rather than focusing on restriction, I find it more useful — and more sustainable — to focus on what to add. Protein at every meal, plenty of fibre from vegetables, pulses and wholegrains, and healthy fats from sources like olive oil, nuts and oily fish all help slow glucose absorption and improve insulin sensitivity over time. The order in which you eat your food can help too: having vegetables and protein before refined carbohydrates in a meal has been shown to blunt the blood sugar response compared to eating carbohydrates first.
My Mediterranean halloumi and quinoa bowl and spiced roasted chickpeas are both built around this principle — protein and fibre together, rather than refined carbohydrates alone. Movement matters too: even a short walk after a meal can meaningfully improve how your body handles the glucose from that meal, and it's a change many of my clients find far easier to sustain than an overhaul of their entire diet.
Consistency Over Perfection
I also encourage clients to pay attention to sleep and stress alongside food, since both influence insulin sensitivity independently of diet. Poor sleep has been associated with reduced insulin sensitivity the following day, and chronically high stress can raise cortisol in ways that also affect blood sugar regulation. This doesn't mean diet doesn't matter — it absolutely does — but it does mean that a client who is eating well but sleeping four hours a night and under constant stress may still struggle to see the improvements they're expecting from food changes alone. I like to look at the whole picture in consultations rather than food in isolation.
What About Weight?
Not every woman with PCOS and insulin resistance is in a larger body, and not every intervention needs to be framed around weight loss. Some of my clients come in specifically wanting support with fertility, skin or cycle regularity rather than weight, and the same food principles — protein, fibre, balanced blood sugar — apply regardless of the goal. I always tailor the conversation to what matters most to the individual client, rather than assuming weight is the primary concern.
One pattern I see often is clients trying to overhaul everything at once, which rarely lasts. I find far more success when we start with one or two meals a day and build from there — swapping breakfast for something with more protein and fibre, for instance, before tackling lunch or dinner. Small, repeatable changes tend to stick far better than a complete diet overhaul that's abandoned within a fortnight.
A Note on Supplements and Medication
Some clients ask about supplements such as inositol, or medications like metformin, for insulin resistance. These fall outside what I can advise on as a nutritionist — if you're considering either, I'd recommend discussing this with your GP or endocrinologist, who can assess whether they're appropriate for you alongside your dietary changes. Bloods and clinical markers such as HbA1c should always be interpreted by your GP or a registered dietitian, not adjusted based on general nutrition advice alone.
Tracking Progress Beyond the Scale
When working with clients on insulin resistance, I encourage tracking progress through a wider lens than weight alone — things like energy levels, cycle regularity, skin changes and how satisfied you feel after meals are all meaningful markers of progress. Blood sugar and hormonal patterns can take several months to shift meaningfully, so I always encourage patience alongside consistency, and celebrating the non-scale changes along the way.
If you'd like a personalised look at how your own eating patterns might be affecting your PCOS symptoms, explore my PCOS nutrition support or book a consultation — we can build a plan that fits your life, not a generic template.