Insulin sensitivity: what is it and how to increase it

Insulin is a hormone produced by the pancreas that plays an important role in how your body processes sugar; it acts like a key, opening your cells to let in sugar. Proper insulin sensitivity is important. Think of it as the lock on your cell into which the insulin “key” fits. If we don’t have enough locks, our cells won’t respond to the key, making them unable to take in the sugar they need for energy.

Insulin resistance is a common feature of type 2 diabetes and is characterized by a lack of sensitivity to insulin. Over time, this resistance to insulin can contribute to chronic health conditions that affect many different systems in the body.

Fortunately, you can make some fairly simple lifestyle changes to increase your insulin sensitivity and ward off the harmful effects of insulin resistance. Keep reading for six strategies to improve insulin sensitivity. 

Insulin helps the cells in our body take in glucose (sugar) from the bloodstream and use it for energy. This powers the cells and removes sugar from the bloodstream, which is very important because sugar that spends too long in the bloodstream can cause damage to the blood vessels, nerves, and organs (Thota, 2021).

Insulin sensitivity is a measure of how well your body can use insulin. If your cells become less sensitive to the insulin in your body and can’t use it, you’ll have higher levels of glucose in your bloodstream, putting you at greater risk for health conditions like prediabetes, type 2 diabetes, heart disease, and metabolic syndrome (Gao, 2017).

Many different factors can affect insulin sensitivity, including age, genetics, high sugar consumption, and obesity (Sampath Kumar, 2019).

Insulin resistance happens when your body loses its ability to use the insulin in your bloodstream. This means that glucose remains in your blood instead of moving into the cells where it can be used (Freeman, 2021).

As your body slowly becomes less sensitive to insulin, it compensates by making more insulin (a condition called hyperinsulinemia). Left untreated, insulin resistance is associated with a range of problems in the body, including (Freeman, 2021; Parmar, 2021; Mirabelli, 2020):

• High blood sugar levels (hyperglycemia)

• Sodium and fluid build-up

• High blood pressure (hypertension)

• High cholesterol

• Increased body fat, particularly around the belly

• Increased inflammation

• Type 2 diabetes mellitus

• Nonalcoholic fatty liver disease (NAFLD)

• Metabolic syndrome

• Heart disease

• Chronic kidney disease (CKD)

• Polycystic ovary syndrome (PCOS), which can contribute to fertility problems

• Some types of cancer, including breast cancer

Typically, healthcare providers rely on various measurements of glucose processing by the body to determine if a person has conditions associated with insulin resistance, like pre-diabetes or diabetes. These include oral glucose tolerance tests, hemoglobin a1c (a measure of your average blood sugar level over the past few months), and a fasting glucose test.

Research shows that insulin resistance and its potential effects on the body develop over many years. It’s estimated that insulin resistance precedes the development of type 2 diabetes by about 10 to 15 years (Freeman, 2021). This means that if you have insulin resistance, but you don’t have diabetes, you have time to take steps to reverse insulin resistance and improve your health. 

Know that even people who have already been diagnosed with prediabetes or diabetes can benefit significantly from keeping their blood sugars within the normal range. The following strategies can help. 

1. Cut out added sugars

One of the most effective ways to increase your insulin sensitivity is by reducing or eliminating added sugars such as fructose, sucrose, and high-fructose corn syrup from your diet (Softic, 2020). 

Consuming excess calories from added sugars, particularly sugar-sweetened beverages, floods your body with sugar, which presses the “insulin button” again and again until it’s no longer responsive (insulin resistance!).Excess sugar consumption has been associated with developing NAFLD and developing insulin resistance in your liver. In the past, high-fat diets got most of the blame for this, but research has shown that added sugars play a more significant role (Softic, 2020). 

Sugar contributes to insulin resistance, as well as high triglycerides and liver inflammation, which can negatively impact your health.Switching out carbonated sugar-laden beverages and juices for sparkling water with a squeeze of lemon is a great alternative that will satisfy your need without the added sugar.

2. Try a Mediterranean diet

Researchers looked at 102 randomized controlled trials studying the effects of various diets on blood glucose control, insulin sensitivity, and the body’s ability to produce insulin (Imamura, 2016).

They found that simply replacing dietary carbohydrates with saturated fat didn’t influence blood sugar control. However, substituting carbohydrates and saturated fat with a diet rich in unsaturated fat helped participants improve their blood glucose levels (Imamura, 2016).

In particular, the Mediterranean diet has been shown to help increase insulin sensitivity for people with obesity compared to other diets. Studies have shown considerable improvements in fasting glucose, glycated hemoglobin (HbA1C), and insulin levels compared with people on low-fat diets (Mirabelli, 2020).

The Mediterranean diet is primarily plant-based and focuses on meals rich in (Mirabelli, 2020):

• Extra-virgin olive oil (EVOO)

• Nuts

• Vegetables

• Legumes

• Wholegrain bread

• Fresh fruits

Dairy products, fish, poultry, and eggs are eaten in low to moderate amounts. Red meat makes a rare appearance in the Mediterranean diet. And an occasional glass of red wine is often consumed with meals (Mirabelli, 2020).

3. Exercise

Increasing your physical activity has always been a mainstay in treating and preventing type 2 diabetes. Exercise offers many health benefits, including (Sampath Kumar, 2019):

• Increasing insulin sensitivity

• Better blood sugar control

• Increasing strength

• Improving body composition

Studies have shown that structured exercise programs effectively improve insulin sensitivity (Sampath Kumar, 2019).

4. Get more sleep

Researchers know that sleep disturbances and not getting enough sleep at night can contribute to the development of type 2 diabetes.

A small study followed healthy volunteers for eight weeks. For the first two weeks, the participants followed their regular sleep routines. Then for the remaining six weeks, participants were instructed to increase their sleep time by one hour per night. At the end of the study, the researchers found that the volunteers had improvements in their blood markers for insulin sensitivity (Leproult, 2015) 

While they agreed that larger studies were needed, the researchers concluded that an extra hour of sleep is an easy and effective way to improve your insulin sensitivity if you’re regularly sleep-deprived (Leproult, 2015). 

5. Try intermittent fasting

Intermittent fasting is a lifestyle diet that involves eating only during a specific time window each day. This could include alternate day fasting, which is one day of eating normally and one day of fasting, or time-restricted eating, where you eat only during a fixed time window (Parmar, 2021).

Studies have shown that it can help with weight loss, increase insulin sensitivity, improve blood pressure, and reduce the risk of heart disease (Parmar, 2021).

6. Lose excess weight

For people with excess body fat, studies have shown that losing 7% of one’s body weight could reduce the likelihood of developing type 2 diabetes by 58% (Freeman, 2021).

In some situations, surgery may be appropriate to help some people manage their weight. Clinical trials have shown that bariatric surgery can improve insulin sensitivity and have positive health benefits for those with type 2 diabetes (Freeman, 2021).

When it comes to insulin sensitivity, it’s a two-way street. Taking control of your lifestyle, diet, and exercise habits can help keep you on track and control your blood sugar to treat and prevent disease. 

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Current version

May 11, 2022

Written by

Ellyn Vohnoutka, BSN, RN

Fact checked by

Yael Cooperman, MD

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About the medical reviewer

Yael Cooperman, MD, Ro

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.