What is insulin resistance and can I reverse it?
Insulin resistance can be meaningfully improved with exercise and a modest weight loss of 7 to 10 percent. You do not need a perfect lifestyle, though dietary choices and meal timing also help.
Insulin resistance means that your body's cells respond less effectively to insulin, the hormone that shuttles sugar from the blood into the cells. Your pancreas then produces more insulin to achieve the same effect. Eventually that compensatory mechanism falls short, causing your blood sugar to rise. Visceral fat (fat around the organs), genetic predisposition and a lack of physical activity are the main causes.
The consequences are not trivial. Insulin resistance increases the risk of type 2 diabetes, high blood pressure, accelerated atherosclerosis and, in women, PCOS. It is also a core feature of metabolic syndrome, a cluster of conditions that substantially raise cardiovascular risk.
Reversal is possible, and exercise is the most powerful tool for achieving it. People who already have type 2 diabetes demonstrably improve their insulin sensitivity through structured exercise. Even more effective: combining a weight loss of 7 to 10 percent with at least 150 minutes of moderate exercise per week. A small study showed that people with obesity and prediabetes who exercised and followed a diet regained twice as much insulin sensitivity as people who followed a diet alone.
What you eat and when you eat also matters. Calorie-rich meals early in the day, eating vegetables and protein before carbohydrates, and moderating carbohydrate intake: all of these help. Early time-restricted eating, in which all meals are completed before the middle of the afternoon, improved insulin sensitivity in a small study of men with prediabetes, even without weight loss. This has not yet been studied in women and has not been confirmed in a larger setting, so treat it with caution.
The shortest summary: a substantial lifestyle change combining eating less and moving more is proven to be effective. You do not need to aim for an ideal body weight; losing just 7 to 10 percent of body weight is already enough to make a difference.
This answer is based on multiple review studies and a summary of eleven studies in people with type 2 diabetes, supplemented by two small controlled studies in people with prediabetes and metabolic syndrome. The evidence for exercise and modest weight loss is solid; the evidence for time-restricted eating is still thin, as it consists of studies with tens of participants and no long-term follow-up.
How do you measure insulin resistance?
There is no single best method for everyone. For daily use, a fasting blood draw with HOMA or QUICKI (calculation methods for insulin resistance) is a reasonable starting point, as long as the result is compared with norms that fit your particular group.
What are the earliest signs of insulin resistance?
Early signs of insulin resistance are measurable long before a diabetes diagnosis: elevated fasting insulin, abdominal fat, abnormal blood fats, and excess fat within the muscles. If you have risk factors, have your fasting insulin measured, because standard blood sugar tests respond too late.
Does strength training help against insulin resistance?
Strength training probably helps against insulin resistance, although the effect is most strongly demonstrated in combination with endurance training and, for additional weight loss, changes in diet.
Does insulin resistance accelerate ageing?
Insulin resistance is associated with measurably faster biological ageing, greater muscle loss, and possibly a higher risk of cognitive decline. Regular physical exercise is the best-supported way to slow this down.
Which foods improve your insulin sensitivity?
Diet can clearly improve your insulin sensitivity. The Mediterranean diet has the strongest evidence base, but the timing and order of your meals also play a demonstrable role.
What does alcohol do to your blood sugar and insulin sensitivity?
The effect of alcohol on your blood sugar depends strongly on context: on an empty stomach the risk of low blood sugar is real, whereas with a meal it may temporarily rise instead. If you have diabetes or use blood-sugar-lowering medication, discuss with your doctor how to incorporate alcohol safely.