Insulin resistance is a condition that affects your body’s ability to use insulin effectively and may be linked to several other health issues. Some dietary and lifestyle habits can help prevent insulin resistance.
Insulin is an important hormone that regulates several processes in your body.
Problems with this hormone are at the heart of many health conditions.
Insulin resistance, a condition in which your cells stop responding properly to insulin, is incredibly common. In fact, the prevalence of insulin resistance is 15.5–46.5% among adults worldwide (1).
However, certain dietary and lifestyle habits can dramatically improve or help prevent this condition.
This article explains all you need to know about insulin and insulin resistance.
Insulin basics
Insulin is a hormone that your pancreas secretes. It regulates the amounts of nutrients circulating in your bloodstream (2).
Although insulin is mostly involved in blood sugar regulation, it also affects fat and protein metabolism (2).
When you eat a meal that contains carbs, the amount of sugar in your bloodstream increases.
The cells in your pancreas sense this increase and release insulin into your blood. Insulin then travels around your bloodstream, telling your cells to pick up sugar from your blood.
This process helps regulate blood sugar levels and prevent high blood sugar, which can have harmful effects if left untreated (3, 4).
However, cells sometimes stop responding to insulin correctly. This is called insulin resistance.
When you have this condition, your pancreas produces even more insulin to lower your blood sugar levels. This leads to high insulin levels in your blood, known as hyperinsulinemia (5).
Over time, your cells may become increasingly resistant to insulin, resulting in a rise in both insulin and blood sugar levels.
Eventually, your pancreas may become damaged, and this can lead to decreased insulin production.
If your blood sugar levels exceed a certain threshold, you may receive a diagnosis of type 2 diabetes.
Insulin resistance is the main cause of this common condition, which affects more than 9% of adults worldwide (6).
Resistance vs. sensitivity
Insulin resistance and insulin sensitivity are related.
If you have insulin resistance, you have low insulin sensitivity. Conversely, if you are sensitive to insulin, you have low insulin resistance (7).
While insulin resistance is harmful to your health, increased insulin sensitivity is beneficial.
SUMMARYInsulin resistance occurs when your cells stop responding to the hormone insulin. This causes higher insulin and blood sugar levels, potentially leading to type 2 diabetes.
What causes insulin resistance?
Many factors contribute to insulin resistance.
One possible cause is increased levels of free fatty acids in your blood, which can cause cells to stop responding properly to insulin (8).
The main causes of elevated free fatty acids are consumption of too many calories and the presence of excess body fat. In fact, overeating, weight gain, and obesity are all strongly associated with insulin resistance (9, 10, 11).
Visceral fat, the harmful belly fat that can accumulate around your organs, may release many free fatty acids into your blood, as well as inflammatory hormones that drive insulin resistance (12, 13).
Although insulin resistance is more common among people with overweight or obesity, anyone can develop it (14).
Other potential causes of insulin resistance include:
- Excessive fructose consumption: High intake of fructose — from added sugars, not from fruit — has been linked to insulin resistance (15, 16).
- Chronic inflammation: Increased oxidative stress and inflammation in your body may lead to this condition (17, 18).
- Inactivity: Physical activity increases insulin sensitivity, while inactivity may contribute to insulin resistance (19).
- Problems with gut microbiota: Evidence suggests that a disruption in the bacterial environment in your gut can cause inflammation, which may worsen insulin resistance and other metabolic problems (20).
What’s more, various genetic and social factors may contribute to insulin resistance. Black, Hispanic, and Asian individuals are at particularly high risk (21).
SUMMARYThe main causes of insulin resistance are overeating and increased body fat, especially in the belly area. Other factors that can contribute include high sugar intake, inflammation, inactivity, and genetics.
How to know if you have insulin resistance
A healthcare professional can use several methods to determine whether you have insulin resistance.
For example, high fasting insulin levels are a strong indicator of this condition (22).
A fairly accurate test called HOMA-IR can estimate insulin resistance based on your blood sugar and insulin levels (23).
There are also ways to measure blood sugar regulation more directly, such as an oral glucose tolerance test — but this takes several hours.
Your risk of insulin resistance increases greatly if you have overweight or obesity, especially if you have large amounts of belly fat (7).
A skin condition called acanthosis nigricans, which causes dark spots on your skin, can also indicate insulin resistance (24).
Low HDL (good) cholesterol levels and high blood triglycerides are two other markers strongly associated with insulin resistance (25).
SUMMARYHigh insulin and blood sugar levels are key symptoms of insulin resistance. Other symptoms include excess belly fat, high blood triglycerides, and low HDL (good) cholesterol levels.
Discover more about Type 2 Diabetes
What to Eat
Essentials
Blood Sugar
Medications
Insulin
MetforminRelated conditions
Insulin resistance is a hallmark of two very common conditions: metabolic syndrome and type 2 diabetes.
Metabolic syndrome is a group of risk factors associated with type 2 diabetes, heart disease, and other health conditions. It’s sometimes called insulin resistance syndrome, as it’s closely linked to insulin resistance (26).
Its symptoms include high blood triglycerides, high blood pressure, excess belly fat, high blood sugar, and low HDL (good) cholesterol levels (27).
You may be able to prevent metabolic syndrome and type 2 diabetes by stopping the development of insulin resistance.
SUMMARYInsulin resistance is linked to metabolic syndrome and type 2 diabetes, two common health conditions around the world.
Relationship to heart health
Insulin resistance is strongly associated with heart disease, which is the leading cause of death around the globe (28, 29).
Many other conditions, including nonalcoholic fatty liver disease (NAFLD), polycystic ovary syndrome (PCOS), Alzheimer’s disease, and cancer, may be linked to insulin resistance as well (30, 31, 32, 33).
Additionally, insulin resistance has been linked to an increased risk of developing major depressive disorder (34).
SUMMARYInsulin resistance is linked to various chronic conditions, including heart disease, NAFLD, PCOS, Alzheimer’s disease, and cancer.
Other ways to reduce insulin resistance
It is often possible to completely reverse insulin resistance by making the following lifestyle changes:
- Exercising: Physical activity may be the single easiest way to improve insulin sensitivity. Its effects are almost immediate (35).
- Losing belly fat: It’s key to target the fat that accumulates around your main organs via exercise and other methods (7).
- Trying to quit smoking, if you do: Tobacco smoking can cause insulin resistance, and quitting should help (36).
- Reducing sugar intake: Try to reduce your intake of added sugars, especially from sugar-sweetened beverages.
- Eating a nutritious diet: Eat a diet that consists mostly of whole, unprocessed foods and includes plenty of nuts and fatty fish.
- Consuming omega-3 fatty acids: These fats may reduce insulin resistance and lower blood triglyceride levels (37).
- Taking supplements: Though more research is needed, some studies suggest that berberine may enhance insulin sensitivity and support blood sugar regulation. Magnesium supplements may be helpful for some people as well (38, 39, 40).
- Getting better sleep: Some evidence suggests that poor sleep causes insulin resistance, so improving sleep quality should help (41).
- Finding ways to manage stress: Research suggests that chronic stress may contribute to the development of insulin resistance. Therefore, stress reduction techniques such as yoga and meditation may be beneficial (42).
- Trying intermittent fasting: Following this eating pattern may improve insulin sensitivity. If you’re interested in trying it, be sure to ask your doctor first to make sure it’s a safe option for you (43).
Most of the habits on this list also happen to be associated with better overall health, a longer life, and protection against chronic disease.
Still, it’s best to consult a doctor about your options, because various medical treatments can be effective as well.
SUMMARYLifestyle strategies such as exercise, healthy eating, and stress management may help reduce or even reverse insulin resistance.
Low carb diets
Low carb diets may be beneficial for metabolic syndrome and type 2 diabetes — and this is partially mediated by reduced insulin resistance (44, 45, 46).
According to the American Diabetes Association, consumption of foods high in carbs and low in fat may actually worsen insulin resistance (7).
Additionally, low carb diets may support weight loss, which could help increase insulin sensitivity (7, 47).
Low carb diets involve limiting your intake of foods high in carbs or added sugar, including baked goods, grains, and sweets.
Diets that are very low in carbohydrates, such as the ketogenic diet, may also improve blood sugar regulation and enhance insulin sensitivity (48, 49).
The ketogenic diet is high in fat but limits carb intake, usually to around 5–10% of total daily calories (50).
According to one review, following a ketogenic diet may help improve blood sugar regulation, decrease inflammation and fasting insulin level, and promote weight loss, all of which may be beneficial for people with insulin resistance (49).
However, it’s important to talk with a doctor or dietitian before making changes to your diet, especially if you are taking medications or have any underlying health conditions, such as diabetes.
SUMMARYLow carb and ketogenic diets may improve insulin resistance and support blood sugar regulation. However, you should talk with a healthcare professional before making major changes to your diet.
The bottom line
Insulin resistance may be one of the key drivers of many chronic conditions, including type 2 diabetes.
You can improve this condition through lifestyle measures such as eating a balanced diet, staying active, and making an effort to maintain a moderate body weight.
Preventing insulin resistance may be among the most effective ways to live a longer, healthier life.