How to reduce insulin

Levels of this hormone can predict health problems years in advance. If your fasting insulin test comes back high, use these proven diet and lifestyle tips to bring your numbers down.

WRITTEN BY

Stephanie Eckelkamp

REVIEWED BY

Nick Nwabueze, MD

Updated: 06/04/2025|12 min read

Insulin is an essential metabolic hormone. It not only plays a star role in regulating blood glucose levels, it also promotes muscle development, controls brain functions, helps regulate appetite, and more. But too much insulin can be a sign you’re at risk for conditions like insulin resistance and Type 2 diabetes—even if your blood glucose levels are currently in the normal range. In fact, elevated insulin levels can precede elevated blood glucose by up to 13 years.

High insulin levels often indicate that someone is less insulin sensitive (sometimes referred to as being more insulin resistant). That means their cells need more insulin than before to “get the message” that they should take up excess glucose from the bloodstream to use for energy or convert to storage forms for later use. Often, this is caused by poor diet (think: lots of refined carbs and added sugars), along with lifestyle factors like too little exercise, too much stress, and poor sleep. Beyond diabetes, elevated insulin and insulin resistance are also associated with heart disease, cancers, cognitive decline, reproductive health problems, and fatty liver disease. (In some states, like pregnancy, some insulin resistance is normal and expected.)

With a fasting insulin test or a HOMA-IR test (which includes fasting glucose), you may be able to identify early stages of insulin resistance and take action before significant long-term damage is done. Here, learn what fasting insulin number to aim for, why elevated insulin is harmful, and proven diet and lifestyle habits to lower your levels.

What is insulin?

Insulin is a hormone produced by beta cells in the pancreas that helps regulate nearly every cell in the body. It’s also the body’s main anabolic hormone, so it plays a role in “building things up” (for example, building glycogen stores, muscles, and bone), as opposed to catabolic hormones, which break things down.

Most people associate insulin with glucose: When blood glucose levels rise after eating a carbohydrate-containing meal, the pancreas secretes insulin to help move excess glucose from the bloodstream into cells to be used for immediate energy needs, or to be stored. Specifically, insulin binds to cell membranes and triggers the movement of a glucose transport protein called GLUT 4 from inside the cell to the cell surface, where it can funnel glucose inside the cell.

Additionally, insulin plays many other roles throughout the body:

• Muscle: Insulin delivers glucose to working muscles for energy; promotes the formation of muscle glycogen (the storage form of glucose), giving us an energy reserve to tap into when needed; and helps stimulate the uptake of amino acids into muscles for protein synthesis.
• Liver: Insulin promotes the formation of liver glycogen from glucose. During periods of fasting, intense exercise, or overnight sleep, our bodies break down liver glycogen to maintain stable blood glucose levels.
• Bone: Insulin supports bone growth and density by promoting the formation of osteoblasts (bone-building cells) as well as enzymes and proteins for bone mineralization.
• Brain: Insulin has been shown to play a role in processing memories, neuroplasticity (the brain’s ability to adapt and form new neural networks), and cognition (thinking, learning, and understanding). It also acts on specific neurons to help control appetite.
• Kidneys: Insulin stimulates the kidneys' reabsorption of sodium, so it’s not all excreted via urine. This helps maintain fluid balance and blood pressure in the body.
• Fat: When glucose levels exceed what the body needs for immediate energy and to fill glycogen stores, insulin stimulates the conversion of glucose into fatty acids and eventually triglycerides (the storage form of fat).

Clearly, insulin is important when it’s working the way it should be. But things start to go wrong when insulin levels remain high and insulin resistance sets in.

What are healthy insulin levels?

Fasting insulin is measured with a simple blood draw after an overnight (eight- to 12-hour) fast. There is no official consensus on optimal fasting insulin levels. Labs often consider anything between roughly 2 and 25 μU/mL “normal,” but many metabolic health experts have said the top of this range is too high and suggest that levels should stay below 10 μU/mL.

Having low insulin levels typically indicates you have high insulin sensitivity. That’s good, because it means that when your pancreas secretes an appropriate (read: not excessive) amount of insulin, your cells respond readily, and blood glucose levels drop to a healthy range.

High insulin levels (hyperinsulinemia), on the other hand, often indicate that cells are insulin resistant. This means that more insulin is needed for cells to effectively take in glucose.

Interestingly, in a vicious cycle, high insulin levels may promote insulin resistance and be a result of insulin resistance. Regardless of which came first, continued hyperinsulinemia will perpetuate insulin resistance—which is why you should take appropriate steps to lower your levels.

Why are high insulin levels dangerous?

Hyperinsulinemia can trigger a cascade of problems in the body.

As previously mentioned, insulin is an anabolic hormone that stimulates the conversion of excess glucose into body fat. So, a person with higher levels of insulin (sometimes caused by repeatedly eating foods that raise blood glucose, such as refined carbs and sugars) will tend to gain more fat mass and have a harder time burning fat than someone with lower insulin levels.

According to Ben Bikman, PhD, metabolic health expert and Levels advisor, “rising amounts of insulin increase body fat even when the number of calories consumed stays the same.” So if Person A eats a 2,500-calorie diet that drives up insulin, they’ll gain more fat than Person B, who eats a 2,500-calorie, metabolically healthy diet that keeps insulin low. This creates a cycle for Person A: As they accumulate body fat, they secrete even more insulin. One study found that fasting and post-meal insulin secretion rates were more than 50 percent higher in people with obesity compared to lean people.

If someone continues to consume a diet that escalates glucose and insulin levels, their fat cells may eventually expand to a degree where they can no longer take up additional fat. At this point, the cells become severely insulin resistant and start leaking free fatty acids into the bloodstream.

In the presence of high insulin levels, the liver converts these free fatty acids into triglycerides, which results in elevated liver triglycerides (a contributor to fatty liver disease) and elevated blood triglycerides. High insulin levels also prompt the kidneys to retain more sodium and uric acid, which contributes to high blood pressure and other health problems.

As more cells become increasingly insulin resistant, eventually the pancreas is unable to pump out enough insulin to compensate for this effect, and blood glucose becomes chronically elevated.

These consequences (excess body fat, especially abdominal fat, and elevated triglycerides, blood pressure, and blood glucose) are all diagnostic criteria for metabolic syndrome, and each increases the risk of Type 2 diabetes, cardiovascular disease, stroke, and other health conditions.

Fortunately, lowering insulin can help maintain insulin sensitivity and prevent these problems.

How to lower insulin levels with diet and lifestyle changes

Whether you know your insulin levels are high or you’re hoping to keep yours in a healthy range, tweaking how you eat and other daily habits can help. Learn how each of these changes impacts your body at the cellular level.

1. Minimize refined carbs and added sugars

One of the biggest dietary contributors to elevated insulin and its associated insulin resistance is a diet high in refined carbohydrates. Repeated blood glucose spikes from these foods lead to repeated insulin surges to clear glucose from the blood. Over time, constant bombardment with insulin can make cells “numb” to its effects.

In turn, this “numbness” (insulin resistance) causes the pancreas to release even more insulin to compensate and maintain normal blood glucose (kind of like someone with caffeine dependence needing more and more coffee to get the same boost of alertness). If continued, this leads to a cycle in which insulin resistance drives up insulin, which further exacerbates insulin resistance.

When you scale back on foods that spike blood glucose (and, in turn, insulin), you counteract this process. The key culprits to avoid include:

• Refined grains (breads, crackers, cereals, pasta)
• Refined potato products (potato chips, fries, potato flour)
• Added sugars
• Liquid carbs like soda and juice

These dense sources of rapidly digested and absorbed carbohydrates lack fiber, protein, and healthy fats—macronutrients that curb blood sugar and subsequent insulin spikes. Interestingly, some dairy products, particularly milk, can trigger excess insulin release compared to what’s expected based on their carbohydrate content, though unsweetened fermented dairy products (e.g., yogurt and kefir) and high-protein cheeses (e.g., parmesan and Swiss) appear to have less of an insulinogenic effect and carry other health benefits.

If you do occasionally choose to eat something denser in carbohydrates, don’t eat it alone. Pairing it with protein, fat, and/or fiber will help slow gastric emptying and therefore curb the post-meal rise in blood glucose and insulin. Similarly, research shows that eating protein and vegetables before carbohydrate-rich foods may result in lower post-meal levels of glucose and insulin.

Several eating patterns that limit refined carbohydrates and added sugars have been shown to lower insulin and improve insulin resistance:

• Mediterranean-style diets—which feature vegetables, fruits, fish, olive oil, nuts, seeds, and unrefined grains, along with moderate amounts of dairy and meat—can be a good starting point. In a recent study that spanned 20 years with outcomes from over 1,900 study participants, those who had a sustained, high level of adherence to a Mediterranean diet had 16% lower fasting insulin levels than those who did not, along with a 57% decrease in Type 2 diabetes.
• Low-carbohydrate diets also improve insulin levels. In one study of people with obesity, those on a low-carbohydrate, high-protein diet (30 percent carbohydrate, 30 percent protein, and 40 percent fat) and those on a Mediterranean-style diet (55 percent carbohydrate, 15 percent protein, and 30 percent fat) had similar improvements in fasting insulin, insulin resistance, insulin clearance, and beta-cell function after four weeks. Tip: You can make a Mediterranean diet lower carb by eating fewer grains and more quality proteins, fats, and non-starchy veggies.
• Ketogenic diets, which typically limit carbohydrates to 5 to 10 percent of total daily calories (with about 70–85% of calories from fat, and 10–20% from protein), can also improve insulin sensitivity and lower fasting insulin. In one meta-analysis, ketogenic diets were found to lower fasting insulin by 29 percent and fasting glucose by 6 percent. Additionally, studies have shown that a ketogenic meal leads to a lower insulin response compared to an equally caloric but higher carbohydrate Mediterranean meal. This makes sense since fewer carbs demand less insulin to keep blood glucose levels in check.

Exactly what dietary pattern and quantity of carbohydrates will help you lower insulin levels will depend on factors such as your baseline insulin levels, how physically active you are, your personal response to various carb-containing foods, and how likely you are to stick to a given eating style.

2. Consider intermittent fasting

When you eat frequently throughout the day—especially foods high in carbohydrates—your pancreas must keep pumping out insulin to process the excess glucose in your bloodstream. Over time, experts say this could potentially lead to prolonged elevations of insulin levels that prime your cells for insulin resistance. On the other hand, going for longer stretches without food (i.e., intermittent fasting or simply restricting your eating window) may give your pancreas a break and allow blood levels of insulin to drop back into a healthier range.

In a meta-analysis of 10 studies, people with impaired glucose and lipid metabolism participated in different intermittent fasting protocols—including eating 500 calories for two non-consecutive days each week, time-restricted eating protocols, and religious fasts—for three months. Fasting insulin dropped an average 13.25 μU/mL and insulin sensitivity improved. But because the IF protocols differed, it’s hard to know which was most effective.

Fortunately, another review of 15 studies found that time-restricted eating was associated with reduced fasting insulin and improved insulin sensitivity in people with prediabetes or obesity. Time-restricted eating—when all food intake is confined to a set “eating window”—is considered one of the most approachable forms of IF. The most significant reductions in fasting insulin and improvements in insulin sensitivity were found in studies with shorter eating windows (four to six hours) compared to eating windows lasting more than eight hours.

Where you position your eating window matters, too. One of the studies in people without diabetes found that an early eight-hour eating window (8 am to 4 pm) was associated with improved insulin sensitivity after just two weeks, but a later eight-hour eating window was not. This may be because the body is naturally more insulin sensitive in the morning among people without diabetes, so the pancreas needs to secrete less insulin to keep blood glucose levels in check than it would if the same foods were eaten later. (If you don’t want to try a formal IF protocol, experts say you may still benefit by eating more of your calories and carbohydrates earlier in the day and keeping dinners smaller and lower in carbs.)

Pairing time-restricted eating with a lower carbohydrate diet may amplify the benefits. One study found that a low-carb diet (less than 26 percent of daily calories from carbohydrates) and an eight-hour eating window each lowered fasting insulin levels and improved markers of insulin resistance, but the combination of the two yielded the most significant improvements.

Keep in mind: Fasting doesn’t work for every person in every scenario. Women, in particular, should pay attention to how they feel while fasting, as they’re more prone to experiencing elevated cortisol levels in response to fasting, which can drive up blood glucose. Monthly hormonal fluctuations can also influence tolerance for fasting. Consider starting with a 12-hour eating window and gradually narrowing it from there, and try these other tips.

3. Boost your fiber intake

Both soluble and insoluble fiber are inversely associated with elevated fasting insulin and insulin resistance. In other words, by eating more fiber, you may lower your risk for these issues.

Supplements may help, too. A meta-analysis of 29 randomized controlled trials (RCTs) reported that soluble fiber supplements (like those containing psyllium husk, inulin, or beta-glucans) reduced fasting insulin levels and markers of insulin resistance in people with Type 2 diabetes. Another meta-analysis concluded that beta-glucans and psyllium were the most effective at improving these biomarkers in this population. Additionally, while the benefits of supplemental fiber tend to be greatest for people with existing metabolic dysfunction, studies have found that taking psyllium reduces post-meal blood sugar and insulin levels in healthy people.

A few potential mechanisms may explain fiber’s link to lower insulin and less insulin resistance:

• Both types of fiber improve satiety by adding bulk to food for minimal calories, which can contribute to reduced risk of weight and fat gain. This is a good thing, as excess body fat is known to increase fasting insulin and post-meal insulin secretion.
• Soluble fiber forms a gel-like substance in the GI tract, which slows the absorption of glucose from dietary carbs into the bloodstream. This buffers the post-meal rise in blood glucose, reducing the demand for and secretion of insulin.
• Gut bacteria ferment soluble fiber into short-chain fatty acids like butyrate. This SCFA can help curb inflammation that might otherwise interfere with insulin signaling and increase insulin resistance.

There is no consensus on the optimal daily fiber intake to lower insulin, but research consistently shows that getting more than 25 grams per day for women and more than 38 grams per day for men is associated with a 20 to 30 percent reduced risk of developing Type 2 diabetes. (Levels advisors recommend up to 50 grams per day.)

Similarly, there’s no consensus for supplemental soluble fiber. Some research suggests that a daily dosage of 7.6 to 8.3 grams may be optimal for overall blood sugar control, and one study in the meta-analyses above found that 10.5 grams of psyllium per day for two months lowered fasting insulin from 27.9 to 19.7 μU/mL, on average.

That said, while supplemental fiber can help you hit your daily fiber goals, always try to optimize fiber intake from whole plant foods (think: flaxseeds, beans, veggies). Most naturally fiber-rich foods contain a combination of soluble and insoluble fibers and are packed with additional nutrients that support healthy insulin levels and insulin sensitivity, like antioxidants. In one study, eating beans, for example, was associated with a reduced post-meal insulin response compared to both a fiber-matched supplement and an antioxidant-matched supplement—suggesting that this benefit isn’t explained by either fiber or antioxidants alone.

4. Eat more colorful plant foods

Diets rich in plant foods, including fully plant-based diets as well as plant-heavy eating patterns like the Mediterranean diet, have been associated with lower fasting insulin levels and reduced insulin resistance. There are several potential reasons for this effect.

Plant-heavy diets tend to be less calorically dense and higher in fiber than diets with fewer plants, which may support healthy insulin levels via the mechanisms discussed in the fiber section above.

Many plants are also a rich source of antioxidants, which can help curb disease-promoting oxidative stress—an imbalance between antioxidants and reactive oxygen species (ROS) in your cells. This stress interferes with insulin’s ability to bind to cells and signal the uptake of glucose, leading to insulin resistance and hyperinsulinemia. Current research links two specific polyphenol antioxidants to improvements in insulin resistance and fasting insulin levels: Epicatechins, found in foods such as cocoa and green tea, and anthocyanins, found in foods such as red cabbage, blueberries, blackberries, and black beans. Other antioxidant nutrients may be beneficial, too, but more research is needed. A good general rule: Including a wide variety of colors in your diet from various plant foods provides a wider variety of antioxidants.

Compared to animal foods, plants also tend to contain higher levels of magnesium—particularly nuts, seeds, legumes, and dark leafy greens. This essential mineral plays a role in hundreds of enzymatic reactions that regulate things like energy production, stress pathways, glucose control, and insulin sensitivity. Although research is mixed, some studies suggest that
adequate magnesium intake is associated with improved insulin sensitivity and a lower risk of developing insulin resistance and Type 2 diabetes.

Finally, plant-based diets tend to contain more unsaturated fats and fewer saturated fats. Some studies link saturated fats to greater insulin resistance compared to mono- and polyunsaturated fats due to impaired insulin signaling in cells, but not all studies agree.

5. Exercise regularly

Exercise—resistance training, aerobic exercise, or a combination—has been shown to support healthy blood glucose levels, improve insulin sensitivity, and lower fasting insulin levels.

When your muscles contract, GLUT4 glucose transporters move from inside of muscle cells to the surface of cell membranes. There, they absorb more glucose from the bloodstream without any additional insulin secretion. Some research suggests this acute increase in insulin sensitivity may persist up to 72 hours after exercise. Even better, when you exercise regularly, the consistently decreased demand for insulin may result in decreased fasting insulin levels and more sustained improvements in insulin sensitivity. Regular exercise can also reduce markers of inflammation and decrease body fat (known contributors to insulin resistance), which may further improve insulin sensitivity and insulin levels.

Any additional physical activity above your baseline is generally helpful—even walking can make a difference if you’re relatively sedentary. In one randomized controlled trial, 30 minutes of brisk walking (at 60 percent of maximum heart rate) three times per week was associated with improved fasting glucose, insulin resistance, and fasting insulin after eight weeks in minimally active women with Type 2 diabetes. On average, fasting insulin decreased from 6.15 to 3.62 μU/mL. (Consider walking after meals to maximize the blood-sugar stabilizing benefits.)

In general, though, the longer and/or harder you work out, the better: Research suggests longer durations of moderate-intensity exercise (for example, 30 to 60 minutes of jogging) and shorter but higher-intensity workouts (think: high-intensity interval training workouts, or HIIT) may both produce significant improvements in insulin sensitivity. Additionally, some studies show that aerobic and resistance exercise training are about equally effective at reducing insulin resistance and lowering fasting insulin levels, but emerging research suggests that regularly engaging in both types of exercise may be the most effective. (Keep in mind, you should step up the duration and intensity of your workouts incrementally over time to stay safe and avoid injury.)

6. Prioritize sleep

Getting enough sleep (about seven to eight hours each night) is vital for maintaining insulin sensitivity. Several studies have found that the pancreas needs to pump out less insulin to keep blood sugar levels balanced when you’re well rested than when you’re not.

In one study on healthy, normal-weight people, those categorized as short-sleepers (less than 6.5 hours per night) had to secrete 50 percent more insulin than normal sleepers (7.5 to 8.5 hours per night) to achieve similar blood glucose levels in response to a glucose-tolerance test. Over time, researchers say, the elevations in insulin related to poor sleep could contribute to insulin resistance.

In another study, restricting sleep to less than 6.2 hours per night for six weeks led to increased fasting insulin levels and an average 15 percent increase in insulin resistance in pre- and postmenopausal women. The postmenopausal women also had increased fasting glucose levels. The exacerbated effects of poor sleep on postmenopausal women may be related to the fact that production of estrogen (which promotes insulin sensitivity) declines significantly during the menopause transition.

Exactly why inadequate sleep is linked to poor metabolic outcomes in all populations isn’t well understood, but researchers believe that a variety of simultaneously occurring factors (such as alterations in growth hormone, increased cortisol, decreased thyroid stimulating hormone, and increased levels of pro-inflammatory cytokines) may interfere with normal insulin signaling in the body.

Fortunately, research suggests the negative metabolic effects of sleep deprivation are reversible once you start getting enough sleep again. In one small study, men who were considered habitual short-sleepers (less than 6.5 hours per night) lowered their fasting insulin levels by 1.6 µU/mL after a six-week intervention in which they got 70 extra minutes of sleep per night.

7. Manage your stress levels

Any habit that helps you manage stress—such as spending time in nature, reading, exercising, meditating, or playing with your dog—has the potential to enhance insulin sensitivity and promote a reduction in fasting insulin levels.

Stress is known to raise levels of hormones like cortisol and epinephrine. These hormones then elevate blood glucose in several ways:

• By interfering with the movement of GLUT4 glucose transporters to cell membranes, thereby reducing the cells’ ability to take in glucose from the bloodstream
• By triggering the release of stored glucose from the liver into the bloodstream (glycogenolysis) and increasing glucose production by the liver (gluconeogenesis)
• By decreasing the production of insulin by pancreatic beta cells

When stress becomes chronic and these processes are frequently triggered, it can lead to insulin resistance, increase the body’s demand for insulin, and elevate fasting insulin levels. Chronic stress can also promote the accumulation of visceral body fat, a known contributor to insulin resistance and elevated insulin levels.

While studies on stress-reduction techniques often show reductions in fasting blood glucose levels, changes in fasting insulin levels tend to be less significant. For example, in a six-month meditation study on patients with heart disease, fasting glucose dropped from 97 to 92 mg/dl, on average, while fasting insulin remained about the same. Overall, however, this demonstrates enhanced insulin sensitivity, because the same amount of insulin was able to more effectively lower blood sugar. And over time, sustained improvements in insulin sensitivity could be expected to result in lower fasting insulin levels.