PCOS & Insulin Resistance: Why Many Women Can’t Lose Weight Even When They Try

By Dr. Rinku Ratti – Private GP Specialist in Womens Health at The Doctor’s Practice, Edgbaston, Birmingham 

One of the most common frustrations I hear from women with polycystic ovary syndrome (PCOS) is: 

“I’m eating healthy, exercising, and I still can’t lose weight.” 

This is never a lack of effort.
For many women, the underlying issue is insulin resistance — a metabolic condition that makes the body store fat instead of burning it. Research shows that over 70% of women with PCOS experience insulin resistance, even those who appear slim on the outside. 

Understanding this connection is the first step to feeling better, improving hormonal balance, and finally seeing progress with weight. 

What Is Insulin Resistance IN PCOS? 

Insulin is a key hormone produced by the pancreas. Its job is simple:
Move sugar (glucose) from your blood into your cells so your body can use it for energy. 

When you have insulin resistance, your cells stop responding properly. As a result: 

• Blood sugar rises 

• The body produces even more insulin to compensate 

• Excess insulin triggers fat storage, especially around the stomach 

• Hunger and cravings increase 

• Energy crashes become frequent 

Over time, this becomes a vicious cycle.
Weight gain worsens insulin resistance, and insulin resistance worsens PCOS symptoms — particularly weight gain, irregular cycles, acne, and hormonal imbalance. 

Why Weight Loss Is So Difficult in PCOS 

Research has repeatedly shown that the combination of insulin resistance and hormonal imbalance makes weight loss significantly harder for women with PCOS. Even with excellent diet and exercise habits, the body often resists change. 

Common factors include: 

🧬 Hormonal imbalance – High androgens and high insulin disrupt metabolism
🍽 Increased cravings – Especially for carbohydrates and sugary foods
😴 Low energy and fatigue – Hard to stay consistent when you’re drained
💠 Higher inflammation levels – Linked to worsened insulin resistance
🌙 Sleep disturbances – Poor sleep increases appetite hormones 

A major 2022 study in the Journal of Clinical Endocrinology & Metabolism confirmed that insulin resistance is one of the primary drivers of weight gain and hormonal symptoms in PCOS. 

Common Symptoms of Insulin Resistance in PCOS 

Many women have insulin resistance without realising it.
Signs may include: 

• Unexplained weight gain 

• Difficulty losing weight despite effort 

• Irregular menstrual cycles 

• Acne, excess hair growth, or hair thinning 

• Fatigue or “brain fog” 

• Cravings for carbohydrates and sugar 

• Low energy after meals 

If you recognise several of these symptoms, it’s worth being assessed. 

Blood Tests We Commonly Check in PCOS

At The Doctor’s Practice, we offer comprehensive PCOS and metabolic testing to help understand the full picture. Useful investigations include: 

• Fasting blood glucose 

• Fasting insulin / HOMA-IR – the most accurate way to detect insulin resistance 

• HbA1c – longer-term blood sugar control 

• Lipid profile – cholesterol and triglycerides 

• Vitamin D, magnesium, and B12 – deficiencies worsen insulin resistance 

• Full hormone profiles if needed (FSH, LH, oestradiol, testosterone, SHBG, prolactin, etc.) 

Accurate testing helps us create a personalised, targeted plan rather than guesswork. 

Treatment Options for PCOS

Improving insulin resistance is one of the most effective ways to support weight loss, restore menstrual cycles, and improve overall PCOS symptoms. 

1. Medical Therapies

These are considered when lifestyle changes alone aren’t enough — which is very common in PCOS. 

• Metformin
  A well-studied medication that improves insulin sensitivity and reduces cravings.
• Inositol supplements (myo-inositol + D-chiro-inositol)
  A natural option shown to improve ovulation, periods, and metabolic health.
• Tirzepatide (Mounjaro®)
  An advanced weekly injection that supports substantial weight loss and improves blood sugar control.
  A major trial published in the New England Journal of Medicine (2022) demonstrated significant improvements in metabolic markers — particularly beneficial for women with PCOS and insulin resistance. 

All treatments are carefully discussed and tailored based on your symptoms, test results, and goals. 

2. Nutrition & Lifestyle Interventions

Small, sustainable changes can make a powerful difference. 

• Low-glycaemic index (low-GI) diet
  Helps stabilise blood sugar and reduce cravings.
• High-protein meals
  Improves satiety and keeps insulin levels stable.
• Strength training
  One of the most effective ways to improve insulin sensitivity.
• Aim for 7–8 hours of sleep
  Even one night of poor sleep increases insulin resistance the next day.
• Omega-3 supplements
  Helps reduce inflammation and improve metabolic health.
• Vitamin D and magnesium
  Crucial for glucose control — especially important if blood tests show deficiency.

When combined, these strategies work far better than dieting alone. 

The Emotional Side of PCOS 

One of the hardest aspects of PCOS is how it affects self-esteem. 

Many women tell me they feel: 

• Frustrated 

• Misunderstood 

• Blamed for their weight 

• Exhausted by repeated attempts with little progress 

This is incredibly common — and understandable. 

PCOS is not simply a “diet and exercise” issue.
It is a complex hormonal and metabolic condition that deserves proper assessment, compassionate care, and tailored treatment. 

A Real Patient Example 

A 28-year-old woman came to The Doctor’s Practice feeling exhausted, gaining weight rapidly, and struggling with her skin and confidence.
Her blood tests revealed significant insulin resistance and low Vitamin D levels. 

We created a personalised, medical and lifestyle plan. 

Within 12 weeks: 

• Her energy levels improved 

• Her menstrual cycles became more regular 

• Her cravings reduced 

• She began losing weight steadily 

• Her mood and confidence lifted 

This story is far from unique.
With the right support, improvement is not only possible — it’s expected. 

How We Help at The Doctor’s Practice 

If you suspect PCOS or insulin resistance, we offer: 

• Comprehensive hormone and metabolic testing 

• In-depth consultation with an experienced GP 

• Personalised treatment plans 

• Ongoing monitoring and support 

• Advice on fertility, skin, and long-term metabolic health 

Our approach is compassionate, evidence-based, and tailored to your unique needs. 

Book an Appointment 

If you’re struggling with PCOS symptoms, weight changes, or possible insulin resistance, we’re here to help. 

📍 The Doctor’s Practice – Edgbaston, Birmingham 
🌐 https://thedoctorspractice.co.uk
📞 0121 661 2366
📱 WhatsApp: 07388 623527 

 References 

1. Dunaif, A. (2022). Insulin resistance and metabolic dysfunction in PCOS. Journal of Clinical Endocrinology & Metabolism. 
   https://academic.oup.com/jcem 

1. Knowler, W. et al. (2021). Metformin and insulin resistance. Diabetes Care Journal. 
   https://diabetesjournals.org/care 

1. Lilly Trial Group. (2022). Tirzepatide improves metabolic markers and weight. New England Journal of Medicine.
   https://www.nejm.org/ 

1. Teede, H. et al. (2021). Emotional & metabolic burden of PCOS. Human Reproduction Update.
   https://academic.oup.com/humupd 

1. Krul-Poel, Y. (2020). Vitamin D deficiency in PCOS. Nutrients Journal. 
   https://www.mdpi.com/journal/nutrients