How to treat insulin resistance

By , medical review by Evidence based

Insulin resistance is a common, almost silent condition in which the body’s cells become less able to efficiently respond to the hormone insulin.

This causes the pancreas to secrete even more insulin to keep blood sugar from rising too high.

As described in our in-depth companion guide: What you need to know about insulin resistance, this becomes a vicious cycle with insulin rising higher and higher and cells becoming even more resistant.

Eventually this may lead to pre-diabetes, type 2 diabetes, PCOS, or other chronic health conditions.

For more information about how and why insulin resistance happens, the health conditions related to insulin resistance, and how insulin resistance is diagnosed please refer to our companion guide.

Doctor consulting with patient presenting results on digital tablet tablet sitting at table

What you need to know about insulin resistance

GuideInsulin is an essential hormone we can’t live without. What happens, however, when it is chronically too high? Our tissues stop responding to it effectively. That’s insulin resistance.

In this guide we describe what you can do to treat insulin resistance, especially with powerful lifestyle interventions.

Can drugs help?

If you have been diagnosed with insulin resistance, your first question may be whether any medications can treat this condition. While the FDA has not approved any drugs specifically to treat insulin resistance, there are two commonly prescribed drugs for diabetes that can improve insulin sensitivity.

Many doctors prescribe metformin for patients with prediabetes and/or insulin resistance. It works by decreasing glucose production by the liver and increasing the insulin sensitivity of cells.

However, it does not address the underlying cause of the insulin resistance.

Pioglitazone is another medication that lowers blood sugar by enhancing the body’s sensitivity to insulin.

This drug tends to not be as popular as metformin, however, in part due to the potential side effect of mild weight gain.

Though drugs may play a role in improving insulin sensitivity and delaying the onset of type 2 diabetes, they are rarely adequate as a sole intervention. What else can you do if you have insulin resistance? This guide explores the lifestyle changes you can make as supported by the latest evidence.

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The low carb diet

Practically any dietary intervention that results in weight loss, especially fat loss within the abdomen, can temporarily improve insulin sensitivity.

A low carb diet certainly fits this description, and may be more effective than low fat diets for improving insulin sensitivity.
One weak observational study even suggested improved survival for those with prediabetes who ate a lower carbohydrate diet, while a stronger nonrandomized trial reported glucose normalization in over 50% of participants with prediabetes.

The reason why low carb diets are good for people with insulin resistance is simple: if you are not eating sugar — or carbohydrates that rapidly digest to sugar — you will have less sugar entering your bloodstream and therefore less of a need to make insulin to move sugar (glucose) out of the blood and into cells.

If your body is already resistant to insulin, creating this internal environment in which high levels of insulin are not needed to maintain normal blood sugars is extremely helpful.

Studies show that a low carb diet can be an effective diet for improving blood sugar control and achieving type 2 diabetes remission.

Since insulin resistance plays a major role in causing type 2 diabetes, a low carb diet is likely also good for addressing pre-existing insulin resistance before full-blown type 2 diabetes develops.

One short study in 2005 showed a 75% improvement in insulin sensitivity in ten patients with obesity and type 2 diabetes who went on a low carb diet.

In two other studies, a very low carbohydrate diet was better at lowering insulin levels than a low fat diet.

Of note, both groups in the latter study demonstrated equal weight loss, suggesting that it was the composition of the diet — not the weight loss alone — that was the most effective intervention to bring insulin levels down.

Yet another trial showed that a low carb diet was better than a low fat diet plus a popular prescription weight loss drug for lowering insulin, glucose and HbA1c levels.

Again, both groups lost the same amount of weight, but the diet with the lower carbohydrate levels achieved better results in blood sugar control and insulin levels.

Finally, one study reports that people with insulin resistance have worse compliance with a low fat diet, and better compliance with a low carb diet.

Takeaway: Reducing your intake of sugar and carbs that digest to sugar will likely result in reduced insulin production and improved insulin resistance.

What does this diet look like? Dozens of guides on our site delve into all aspects of low carb and ketogenic eating. Check out these two to start:

Low-carb diet
A low carb diet for beginners

Guide A low carb diet is low in carbohydrates, primarily found in sugary foods, pasta and bread. Instead, you eat real foods including protein, natural fats and vegetables. Studies show that low carb diets result in weight loss and improved health markers.

DD_ketofood_mobile_blue3
A ketogenic diet for beginners

Guide A keto or ketogenic diet is a low carb, high fat diet that can help you burn fat more effectively. It has many benefits for weight loss, health and performance, as shown in over 50 studies. It’s also used and recommended by many doctors.

Other dietary evidence

It is important to note that studies also show that any diet that causes weight loss can reduce insulin resistance and improve insulin sensitivity — at least for a time.

The reverse is true, too. Any diet that causes a rapid increase in bodyweight, such as from consuming high carb, high fat, high calorie foods (sometimes called over-nutrition), can immediately cause insulin resistance — within days — even among healthy young men.

Over the years, other areas of research have explored the possibility of specific diets decreasing insulin resistance:

  • increasing protein intake
  • increasing dietary fiber intake
  • eating low-glycemic index foods
  • lowering dietary fat intake

To learn more about the strengths and weakness of these other dietary approaches, and why we recommend low carb eating, click below:

Learn more
Dietary fiber

Should you eat more fiber to improve insulin sensitivity? The answer is likely yes, at least compared to eating a diet high in refined carbohydrates and low in fiber.

The fiber in your diet comes from carbohydrate-based plant foods the body cannot digest. There are two types of fiber: soluble fiber, which dissolves in water, and insoluble fiber, which does not dissolve in water and passes through the digestive tract largely unchanged. Soluble fiber is found in many edible plants such as peas, beans, leafy green vegetables, oats, and fruit. Insoluble fiber is largely from the bran (the outside shell) of whole grains.

Studies have shown that diets high in both types of fiber reduce insulin resistance when compared to diets high in refined carbohydrates and low in fiber (Diabetes Care 2006: Cereal fiber improves whole-body insulin sensitivity in overweight and obese women [randomized trial; moderate evidence]).

Low carb diets, which include plenty of above-ground vegetables, are often high in soluble fiber. We are not aware of any studies that have been done comparing a low carb, high fiber diet to a high carb, high fiber diet to see which is more effective for reducing insulin resistance. However, our opinion is that eating low carb, high-soluble fiber foods may be the better strategy for improving insulin sensitivity.

Low glycemic index carbohydrates

Foods that have exactly the same carbohydrate content can differ in terms of blood sugar response, or how much blood sugar goes up after consuming the food. This is called the food’s “glycemic index” (GI).

While one might assume lower-GI foods that cause less blood sugar impact would naturally promote improved insulin sensitivity, study results have been mixed.

One 2014 randomized controlled trial found no difference between high and low GI foods (while keeping carb levels constant) on insulin sensitivity (Journal of the American Medical Association 2014: Effects of high vs low glycemic index of dietary carbohydrate on cardiovascular disease risk factors and insulin sensitivity: the OmniCarb randomized clinical trial [randomized cross over; moderate evidence]).

A 2018 systematic review and meta-analysis found low GI carbs did improve blood sugar levels on a number of measures, but the analysis did not examine the impact on insulin levels or insulin sensitivity (Nutrients 2018: The effect of dietary glycaemic index on glycaemia in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials [strong evidence]).

A 2014 RCT reported a moderate carb/low GI diet was superior to a low fat/high-GI diet with respect to improving insulin sensitivity (American Journal of Clinical Nutrition 2014: Effect of the glycemic index of the diet on weight loss, modulation of satiety, inflammation, and other metabolic risk factors: a randomized controlled trial[randomized trial; moderate evidence]).

As the scientific debate continues, our opinion is that low carb, low-GI foods may be the best bet for addressing insulin resistance.

Dietary fat

Some researchers cite high dietary fat consumption as a primary cause of insulin resistance. However, most of the data suggesting this come from rodent studies that suffer from confounders that may limit extrapolation of the data to humans. (Clinical Nutrition 2004: Dietary fat, insulin sensitivity and the metabolic syndrome [review article; ungraded]).

For example, many of these studies fed the rodents with a high fat “chow.” (American Journal of Physiology, Endocrinology and Medicine 2010: A high fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain [mouse study; very weak evidence]).

The fats were usually low-quality industrial vegetable oils rich in omega-6 fats such as soybean oil; the chow was typically devoid of naturally occurring foods. It is impossible to know if the insulin resistance resulted from the carb content of the chow in combination with the fat, the pro-inflammatory nature of the synthetic chow, the calories, or simply from the fat itself.

Human studies suggesting fat, specifically saturated fat, worsens insulin resistance are frequently confounded by experimental diets that are high in both carbohydrate and fat. For instance, one study from Diabetes Care used a diet comprised of 57% carbohydrate and 28% fat, and another study protocol administered 45% of calories as carbohydrates (Diabetes Care 2002: Effects of diets enriched in saturated (palmitic), monounsaturated (oleic), or trans (elaidic) fatty acids on insulin sensitivity and substrate oxidation in healthy adults [randomized controlled trial; moderate evidence];

Diabetologia 2001: Substituting dietary saturated fat for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU study [randomized controlled trial; moderate evidence]).

Because some experts hypothesize that inflammation may be the underlying mechanism linking fat to insulin resistance, it is no surprise that high fat intake in the presence of high carbohydrate, potentially pro-inflammatory foods could make insulin resistance worse (Lipids in Health and Disease 2015: The role of fatty acids in insulin resistance [overview article; ungraded]).

In fact, one study showed that replacing carbohydrates with monounsaturated fat improved insulin sensitivity, which suggests fat may not be the problem. Instead the key may be to lower dietary carbohydrates (Diabetes Care 2013: The effects of carbohydrate, unsaturated fat, and protein intake on measures of insulin sensitivity [randomized controlled trial; moderate evidence]).

In addition to considering confounding variables that limit conclusions we can draw from trials showing that fat increases insulin resistance, it’s also important to recognize there are many human intervention trials showing no effect of dietary fat on insulin resistance. European Journal of Clinical Nutrition 1999: Comparison of the effects of a monounsaturated fat diet and a high carbohydrate diet on cardiovascular risk factors in first degree relatives to type-2 diabetic subjects[randomized trial; moderate evidence]

European Journal of Clinical Nutrition 1996: The effects of monounsaturated-fat enriched diet and polyunsaturated-fat enriched diet on lipid and glucose metabolism in subjects with impaired glucose tolerance[randomized trial; moderate evidence]

Diabetes 1992: Comparison of effects of high and low carbohydrate diets on plasma lipoproteins and insulin sensitivity in patients with mild NIDDM[randomized trial; moderate evidence]

Journal of Clinical Endocrinology and Metabolism 1991: Comparison of the effects on insulin sensitivity of high carbohydrate and high fat diets in normal subjects[randomized trial; moderate evidence]

We are not aware of any high-quality human studies that adequately control for the amount and type of calories, the amount and type of carbohydrates, and the amount and type of fat in a way that would allow the study authors to assess whether fat consumption causes (or improves) insulin resistance or hyperinsulinemia.

In our opinion, it is likely that the consumption of processed foods high in both carbs and fat contribute most to developing insulin resistance.

 
Takeaway: A diet that is low in carbs, higher in protein, and high in soluble fiber from above-ground vegetables appears to have the best current evidence for reducing insulin resistance.

Intermittent fasting/time-restricted eating

Intermittent fasting is a popular dietary trend that entails exactly what it sounds like: not eating during certain time periods. Though it may seem like a fad to some, studies suggest intermittent fasting can improve insulin sensitivity.

Although not all studies agree. For instance, one RCT that did not control for how much or what the subjects ate, didn’t demonstrate a benefit in insulin sensitivity for those doing 16:8 time-restricted eating.

One lesson to draw from this is that what you eat and how much you eat is just as or likely even more important than when you eat.

There are multiple mechanisms by which fasting may improve insulin sensitivity. Cells can increase the number of insulin receptors on their surface, and those receptors can demonstrate an increased affinity for binding insulin during fasting.

Also, various hormone levels increase during fasting and are thought to increase insulin sensitivity.

For example, adiponectin – a fat-cell specific hormone – appears to enhance insulin sensitivity through increased fatty acid oxidation and inhibition of glucose production by the liver.

When it comes to implementing intermittent fasting, time-restricted eating is one type of fasting that involves eating meals within a set time-frame each day, such as between 11 am and 7 pm. A review of studies in healthy subjects showed that eating fewer meals during a shorter feeding window resulted in better glucose and insulin levels.

Another type of IF is alternate day fasting. Healthy males who fasted for 20 hours every other day for 15 days showed greater glucose uptake with the same insulin levels, in essence improving their insulin sensitivity.

Another trial reported greater improvements in insulin resistance among women using intermittent caloric restriction (fasting) compared to chronic caloric restriction.

Based on the fact that both fasting and low carb diets have been shown to improve insulin sensitivity, we hypothesize that the combination of a low carb diet with periodic intermittent fasting is likely the most effective nutritional intervention for treating insulin resistance and hyperinsulinemia.

Intermittent fasting may seem daunting, but if you are interested in exploring it, check out our guide:

Intermittent fasting

Intermittent fasting for beginners

Guide Intermittent fasting can help you lose weight, increase energy and gain several health benefits. You can also save lots of time and money. There are, however, many questions about how to do IF in a safe and effective way. In this guide by Dr. Jason Fung, a top fasting expert, you’ll quickly learn how to do it.

Physical activity and exercise

Muscles burn glucose for energy. The more you move, the more glucose your muscles take out of the blood for energy use, which helps to lower your blood sugar levels. This allows for a reduction in insulin secretion, lessening the burden on your pancreas.

Likewise, muscles that don’t move don’t need to use much glucose, leading to a rise in insulin levels to process the excess blood sugar. Studies show that a mere five days of bed rest induces a state of insulin resistance in completely healthy volunteers.

Multiple studies show that long-term inactivity is strongly associated with insulin resistance, metabolic syndrome and pre-diabetes.

Any type of regular movement can help. Studies suggest that high-intensity interval training (HIIT), resistance training, and cardio training all improve glucose utilization and thereby improve insulin sensitivity.

No matter what your preferred form of movement or exercise, it is clear: inactivity can lead to insulin resistance. And movement increases insulin sensitivity as long as the exercise continues.

So if you stop moving regularly, insulin resistance may come back. (Move it or lose it!)

One more thing on exercise: you likely cannot outrun a bad diet. Exercising regularly but still eating a high carbohydrate, high-sugar diet will likely partially, if not completely, counteract many of the benefits derived from exercise.

Based on the evidence, it appears that the combination of regular exercise and a well formulated low carb diet is an effective approach for treating insulin resistance and hyperinsulinemia.

Sleep

Studies show that short-term sleep deprivation raises glucose levels and worsens insulin resistance.

A chronic sleep disturbance, such as from obstructive sleep apnea, is also associated with worsening insulin resistance.

It’s unclear how much sleep is too little, just enough, or too much. Is there a difference in insulin sensitivity in someone who gets six hours of sleep per night instead of eight? Is there a certain amount of lost sleep, or a frequency of bad nights that triggers insulin resistance? We don’t know.

However, it is clear that there is an association between insulin resistance and sleep. And treating sleep problems may result in improved insulin sensitivity.

Stress

Studies show temporary insulin resistance arises during periods of short term physiological and psychological stress, such as a sudden illness or sudden threat.

In theory, this could have been an evolutionary advantage at some point in human existence and has been termed “adaptive insulin resistance”.
It makes sense that you would want to mobilize stored energy during infection, trauma, or stress, so inhibition of insulin (which stores energy) would be a good thing. This type of insulin resistance reverses when the sudden stress is over. Such a response to short-term stress likely has no long-term negative consequences.

However, it appears that chronic stress and chronic activation of the body’s fight or flight response will also lead to insulin resistance.

Since this chronic stress is longer-term, without a sudden onset or quick resolution of the trigger, it may lead to longer-term negative consequences.

Two small controlled studies demonstrated that meditation alone helped reduce blood sugar in patients with heart disease.

Since mindfulness training, yoga, meditation, dancing, singing, and walking in nature can be effective ways to reduce stress, increase wellbeing and improve overall physical health, they may also help with insulin resistance.

Explore the ways that you relax best, and you may be helping improve your insulin sensitivity.

Tobacco use

No aspect of smoking is good for health, but some studies report that active smoking is associated with insulin resistance and the development of diabetes.

Can we cure insulin resistance?

Once someone has dramatically improved their insulin resistance, bringing insulin and blood sugar levels down by eating a low carb diet, and they have improved their exercise, stress management, and sleep, the question then becomes: are they cured?

Probably not. The word cure implies that the person can go back to eating however they want and the insulin resistance will not return. Unfortunately, that’s not how it works. The vast majority of people who reverse their insulin resistance, lower their chronically high insulin levels, and lower their blood sugars will see those all return to previous high levels if they stop their lifestyle interventions and return to their old diets and habits.

This reinforces the need to make lifestyle changes that can be maintained for decades and lifetimes. Crash diets or short-term interventions only help in the moment. Insulin sensitivity is a lifelong balance.

However, some people may have what amounts to a partial cure, especially if their insulin resistance is caught early. Clinical practice suggests that for some people, eating a low carb diet, losing weight and getting insulin levels down will restore insulin sensitivity and may allow them to regain the degree of metabolic flexibility found in healthy individuals.

That metabolic flexibility may allow them to increase the amount of carbs they can safely eat from 20 grams per day up to 75 grams, or it may allow them to reduce the amount of exercise they need to keep blood sugar and insulin levels low.

In addition to maintaining weight loss, regular blood tests may be required to determine who will achieve metabolic flexibility and how much flexibility they can “get away with” without triggering the cycle of insulin resistance again.

So the best advice may be to stick with the most intensive lifestyle change you can maintain and be vigilant about screening for recurrence of insulin resistance. This starts with keeping an eye on your waist size, but also may include regular (every 6 months or so) blood tests for fasting insulin and fasting glucose.

See our companion guide What you need to know about insulin resistance, which discusses diagnostic tests.

You can also measure your 2-hour post-meal blood sugar levels after a low carb meal and a moderate-carb meal and compare the readings. If a moderate carb meal causes your blood sugar to go over 140 mg/dl (7.8 mmol/L), that could be a sign that you may still be insulin resistant.

Note that this is our expert opinion, and not based on hard data.

Woman with diabetes checking her blood glucose using her glucose meter

What you need to know about blood sugar

Guide If you have a diagnosis of diabetes, you’ve probably been tracking your blood sugar for years. But if you’ve recently decided to try a low carb or ketogenic diet, you may need to understand your results in the context of your new dietary pattern.

Summary

Insulin and its proper functioning are important for survival and good long-term health. Obesity, metabolic dysfunction, and chronically high insulin levels make your body less responsive to this essential hormone, which might increase your risk of developing serious chronic health conditions.

Adopting effective lifestyle changes — like a low carb diet, regular physical activity, and a good sleep routine — can lower insulin levels and reduce insulin resistance.

/Dr. Bret Scher, MD

Doctor consulting with patient presenting results on digital tablet tablet sitting at table
What you need to know about insulin resistance

Guide Insulin is an essential hormone we can’t live without. What happens, however, when it is chronically too high? Our tissues stop responding to it effectively. That’s insulin resistance.

Woman using glucometer on blue background, top view
What you need to know about diabetes

Guide Do you have type 2 diabetes, or are you at risk for diabetes? Do you worry about your blood sugar? Do you have type 1 diabetes or care for someone who does? Then you’ve come to the right place.

Woman with diabetes checking her blood glucose using her glucose meter
What you need to know about blood sugar

Guide If you have a diagnosis of diabetes, you’ve probably been tracking your blood sugar for years. But if you’ve recently decided to try a low carb or ketogenic diet, you may need to understand your results in the context of your new dietary pattern.