Insulin Resistance: What It Is, Why It Matters, and How to Improve It
Insulin resistance has become a popular health topic, particularly in discussions around weight gain, menopause, polycystic ovary syndrome (PCOS), and type 2 diabetes. However, there is also a great deal of misinformation surrounding the condition.
Understanding what insulin resistance is—and what it isn't—can help you make informed decisions about your health.
What Is Insulin Resistance?
Insulin is a hormone produced by the pancreas that helps move glucose (sugar) from the bloodstream into the body's cells, where it can be used for energy.
Insulin resistance occurs when the body's cells become less responsive to insulin. As a result, the pancreas produces more insulin to keep blood sugar levels within a healthy range. Over time, this increased demand can lead to elevated blood glucose levels, prediabetes, and eventually type 2 diabetes.
Importantly, insulin resistance is not the same as diabetes. Many people with insulin resistance have normal blood sugar levels for years before any signs of diabetes develop.
What Causes Insulin Resistance?
Insulin resistance develops due to a combination of genetic, hormonal, and lifestyle factors.
The strongest risk factors include:
Carrying excess weight, particularly around the abdomen
Physical inactivity
Increasing age
Family history of type 2 diabetes
PCOS
Menopause-related hormonal changes
Certain ethnic backgrounds
Fat accumulation around the liver and other organs (visceral fat)
While obesity increases the risk, insulin resistance can also occur in people who appear to be a healthy weight, particularly if they carry excess visceral fat around their internal organs.
Common Signs and Symptoms
Many people have no obvious symptoms of insulin resistance.
When symptoms do occur, they may include:
Fatigue or low energy
Increased hunger
Difficulty concentrating
Weight gain, particularly around the abdomen
Difficulty losing weight
Sugar cravings
Elevated blood glucose levels
Because these symptoms are non-specific, insulin resistance is often identified through blood tests performed for other reasons.
Insulin Resistance and Menopause
Insulin resistance becomes more common during the menopause transition.
Declining oestrogen levels are associated with increased abdominal fat storage, reduced muscle mass, and changes in metabolism. These changes can make weight management more challenging and may increase the risk of developing insulin resistance and type 2 diabetes.
This is one reason why many women notice weight gain around the middle during perimenopause and menopause, even when their diet and activity levels have not significantly changed.
How Is Insulin Resistance Diagnosed in the UK?
There is currently no single NHS test routinely used to diagnose insulin resistance itself.
Instead, healthcare professionals often assess for related conditions such as:
Prediabetes
Type 2 diabetes
Metabolic syndrome
Tests may include:
HbA1c (average blood glucose over three months)
Fasting blood glucose
Oral glucose tolerance testing in some circumstances
Insulin levels are not routinely measured in primary care, which can sometimes lead to confusion among patients seeking assessment for insulin resistance.
Can Insulin Resistance Be Reversed?
The good news is that insulin resistance can often be significantly improved.
Research consistently shows that lifestyle changes remain the most effective first-line treatment. Even modest weight loss can have a meaningful impact on insulin sensitivity and reduce the risk of developing type 2 diabetes.
Evidence-Based Ways to Improve Insulin Sensitivity
1. Increase Physical Activity
Exercise helps muscles use glucose more effectively and improves insulin sensitivity.
Current UK recommendations advise adults to aim for:
At least 150 minutes of moderate-intensity activity each week
Strength training exercises on at least two days per week
Both aerobic exercise and resistance training have been shown to improve insulin sensitivity.
2. Focus on Sustainable Weight Loss (if indicated)
For people carrying excess weight, losing as little as 5–10% of body weight can significantly improve metabolic health and reduce diabetes risk.
The most effective approach is usually a modest calorie deficit combined with regular exercise rather than extreme or highly restrictive diets.
3. Prioritise Whole Foods
Evidence supports eating patterns that focus on:
Vegetables and fruit
Whole grains
Beans and legumes
Lean protein sources
Oily fish
Healthy fats such as olive oil and nuts
Rather than eliminating carbohydrates completely, choosing high-fibre, minimally processed carbohydrates can help support stable blood sugar levels and overall health.
4. Improve Sleep and Manage Stress
Poor sleep and chronic stress can negatively affect insulin sensitivity and appetite regulation.
Prioritising sleep, stress management, and recovery should be considered part of any long-term metabolic health strategy.
What About Medications?
For some individuals, particularly those with prediabetes, type 2 diabetes, or PCOS, medication may be appropriate.
Metformin is the most commonly used medication to improve insulin sensitivity and may be prescribed in certain clinical situations. Decisions about medication should always be made in partnership with a healthcare professional.
The Bottom Line
Insulin resistance is a common metabolic condition that often develops silently over many years. It plays an important role in the development of prediabetes, type 2 diabetes, cardiovascular disease, and weight gain.
Despite the growing popularity of "insulin resistance diets" and quick-fix solutions online, the strongest evidence continues to support the fundamentals: regular physical activity, strength training, good-quality nutrition, adequate sleep, and sustainable weight management.
Small, consistent lifestyle changes can significantly improve insulin sensitivity and reduce long-term health risks, regardless of age or stage of life.
