Weight loss and gain

Insulin resistance

Also called: insulin insensitivity, metabolic insulin resistance, pre-diabetes

Insulin resistance is when the body's cells respond less to insulin, the hormone that tells them to take in glucose from blood. The pancreas compensates by producing more insulin, which keeps blood sugar normal for years before it eventually slips. It is the stage between metabolic health and type 2 diabetes, and it is largely reversible with sustained changes to diet, sleep and movement.

What is happening

After meals, blood sugar rises and the pancreas releases insulin. Insulin signals to muscle, fat, and liver cells to take up the sugar and store it. In insulin resistance, those cells stop responding properly. The pancreas works harder, releasing more insulin to do the same job. For a long time blood sugar still looks normal on a basic test, but insulin levels are quietly very high. Over years the pancreas gets tired, and that is when blood sugar starts to rise.

Signs you might be insulin resistant

  • Persistent weight gain around the middle that is hard to lose, especially after age 35.
  • Strong sleepiness about an hour after meals, particularly carb-heavy ones.
  • Frequent hunger and snacking, even shortly after eating.
  • Skin tags or darker velvety patches behind the neck, armpits, or groin (acanthosis nigricans).
  • High triglycerides and low HDL cholesterol on a routine blood test.
  • Polycystic ovary syndrome (PCOS) in women is closely linked to insulin resistance.

How it is measured

  • Fasting glucose: the basic test. Often normal until late.
  • HbA1c: average blood sugar over 3 months. Picks up resistance late, useful for diabetes risk scoring.
  • Fasting insulin: rarely run by GPs but very useful. High fasting insulin with normal glucose is the classic insulin-resistant pattern.
  • HOMA-IR: a calculation from fasting glucose and fasting insulin. The most common research metric.
  • Continuous glucose monitor traces: post-meal spikes lasting more than 2 hours and slow returns to baseline are practical real-world signals.

What actually reverses it

  1. Lose 5 to 10 percent of body weight if you carry it around the middle. The single biggest lever.
  2. Walk daily, especially after meals. 10 minutes of walking after eating measurably blunts the post-meal glucose rise.
  3. Build muscle. Resistance training twice a week increases the storage capacity of muscle, which absorbs glucose without needing as much insulin.
  4. Sleep at least 7 hours. One bad night raises next-day insulin resistance measurably.
  5. Cut ultra-processed snacks and sugary drinks first. The biggest fast wins are usually here, not in eliminating whole food groups.
  6. Eat protein and fibre at each meal. Both slow the glucose curve and reduce the insulin spike.

When medication enters the picture

Metformin is sometimes prescribed for insulin resistance with PCOS or pre-diabetes risk. GLP-1 drugs like Wegovy and Mounjaro improve insulin resistance both by lowering weight and through direct effects on glucose handling. None of these substitute for the lifestyle changes above, but they can make those changes more sustainable in people for whom willpower alone has not worked.

Common questions

Can I be insulin resistant at a normal weight?
Yes. About 1 in 8 people with normal BMI have metabolic features of insulin resistance, often related to fat stored inside organs (liver, around the heart) rather than under the skin. Asian populations carry higher rates of normal-weight insulin resistance for genetic reasons.
Is insulin resistance the same as diabetes?
No. Insulin resistance is the underlying state. Diabetes is what happens when the pancreas can no longer compensate and blood sugar starts running high. Insulin resistance can exist for 10 to 20 years before diabetes develops, which is exactly why it is worth catching early.
Does intermittent fasting help insulin resistance?
Mildly. The evidence suggests intermittent fasting works mostly by reducing total calorie intake and giving the body extended low-insulin windows. It is one tool among many. People who hate fasting do not need to do it. Eating consistent, lower-glycaemic meals across the day works just as well for most.
Can a continuous glucose monitor diagnose insulin resistance?
Not formally, but it is one of the most useful real-world signals. A 2-hour post-meal glucose still 30 to 40 mg/dl above baseline, daily morning glucose creeping above 100 mg/dl, and large spikes from modest meals all point to early insulin resistance worth investigating with a fasting insulin blood test.

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