Insulin resistance is when the cells in the body do not absorb insulin properly. Over time, insulin resistance can cause a range of problems, including permanently high blood sugar levels and cell damage to organs, muscle, limbs, and eyes.
People with insulin resistance often receive a diagnosis of prediabetes, which might lead to type 2 diabetes. People who are insulin resistant may need extra checks to make sure they do not develop type 2 diabetes.
Certain diet and other lifestyle choices can increase the risks related to insulin resistance. Making dietary changes can improve insulin sensitivity and reduce insulin resistance and the risk of developing type 2 diabetes.
In this article, we look at the dietary and lifestyle changes a person can make to increase their body's sensitivity to insulin.
Foods to eat
A balanced diet can help people control their blood sugar levels.
These nutrients are essential for maintaining blood sugar levels. People with insulin resistance should seek out foods that contain plenty of these nutrients.
According to the American Diabetes Association, people with insulin resistance can eat from any food group. However, it is important to understand which foods increase blood sugar and which support insulin sensitivity.
- non-starchy vegetables, such as broccoli, dark leafy greens, and peppers
- tomatoes, which are an excellent source of vitamins C and E
- citrus fruits, such as lemons, oranges, and limes
- high-fiber foods, including beans and lentils
- some whole grains, such as oats, quinoa, and barley
- protein-rich foods, including lean meats, fish, soy, legumes, and nuts
- fish with a high omega-3 fatty acid content, such as salmon, sardines, and herring
- foods that contain antioxidants, such as berries
- sweet potatoes, which have a lower GI than regular potatoes
- water, especially as a substitute for sweetened drinks
- unsweetened teas
- unsweetened yogurt
Foods to avoid
Certain foods are more likely to raise blood sugar. Regularly eating foods with high sugar content can overload the body's ability to produce enough insulin.
It can also limit the ability of cells to absorb the sugar. If the cells become saturated with too much blood sugar, or glucose, they will gradually respond less and less to insulin.
When this happens, the glucose remains in the blood, contributing to the health problems that accompany consistently raised blood sugar, such as damage to the kidneys (nephropathy) or limbs (neuropathy).
Avoiding or significantly limiting the following foods can help moderate blood sugar level:
- sweetened beverages, including fruit juices, soda, and fountain drinks
- alcohol, particularly beer and grain alcohol, especially in large quantities
- starchy vegetables, such as potatoes and yams (especially without skin), pumpkin, corn
- processed snacks and boxed foods
- sugary sweets, such as cupcakes, ice cream, or chocolate bars
- refined grains, such as white bread, rice, pasta, and flour-based foods, which are lower in fiber than whole grain versions
- dairy from cows, especially milk
- fried foods, even if it is a type of food that would be less harmful cooked another way, such as vegetables
- foods high in saturated fats, including chocolate, butter, and salt pork
Finding a healthful balance
However, people can still eat foods on this list occasionally without causing any long-term harm to their insulin sensitivity. The key is to limit these foods and replace them with more healthful options as often as possible.
Sometimes, the occasional treat can help a person satisfy their sweet tooth and focus on adjusting their diet more regularly.
By sticking to a high-fiber, plant-based diet that is low in added sugars, a person can steadily improve their insulin sensitivity.
Daily exercise is also a significant factor. During activity, the muscles soak up glucose from the bloodstream and do not require insulin. Taking a walk after a meal and being active throughout the rest of the day can significantly improve blood sugar management.
By losing 5–10 percent of their body weight, a person can also significantly improve insulin sensitivity.
These lifestyle changes can reduce the risk of type 2 diabetes, cardiovascular disease, and other health problems.
The Mediterranean diet can improve insulin sensitivity.
Following a fixed diet plan, such as the Mediterranean Diet, can improve insulin sensitivity.
The Mediterranean diet involves eating lots of seasonal, plant-based foods, eating fruit for dessert, and using olive oil as the primary source of fat. People following this diet eat fish, poultry, legumes, and nuts as main protein choices and dairy products in moderation.
Mediterranean eaters also limit their intake of red meat and consume a little wine during meals.
People should base daily calorie intake on their weight loss goals and body size.
The Mediterranean Diet is just one option for healthful eating. Other diet plans, such as the DASH (Dietary Approaches to Stop Hypertension) and ketogenic diets, also offer ways to improve insulin resistance. These work well when a person combines them with other healthful lifestyle practices, such as stress management, adequate sleep of 7 to 9 hours each night, and regular physical activity.
One of the simplest ways to tackle insulin resistance is to eat foods with a low glycemic index (GI) and load (GL).
The GI lists carbohydrate-containing foods by how quickly they increase the glucose levels in a person's blood. GL takes into account the GI of a food plus the serving size.
Carbohydrates with a high GI and GL can cause blood sugar spikes and put more demand on the body to make insulin. However, the digestive system processes low-GI and GL foods slowly, which reduces blood sugar spikes.
Eating low-GI and GL foods is an excellent way to maintain balanced blood sugar levels and preserve insulin sensitivity. It is essential to consider both GI and GL for ideal blood sugar management.
Understanding insulin resistance
The body needs glucose for energy. However, many cells cannot absorb glucose unassisted.
The pancreas secretes insulin into the bloodstream. The insulin then helps the glucose travel to the body's cells, which use it for energy.
Insulin allows cells to absorb glucose, making sure that:
- blood sugar levels remain at a safe level
- muscle, fat, liver, and other cells can get energy
When a person has insulin resistance, their cells are less sensitive to insulin. This means the pancreas has to produce more insulin to keep blood sugar levels healthy.
If the pancreas is unable to keep up with the increased demand for insulin, blood sugar levels rise. Cells cannot always use all of the excess glucose in the blood, which can lead to high blood sugar levels, type 2 diabetes, and various other health issues.
Research suggests that ethnic and genetic factors may increase the risk of insulin resistance. However, lifestyle factors also make a difference.
Making positive changes to daily habits can significantly decrease insulin resistance and the risk of diabetes.
Diet affects insulin resistance in at least two major ways.
Firstly, consuming too many calories, whether from excess fat, sugar, or alcohol, can trigger weight gain. This increases the risk of insulin resistance. Regular physical activity can counteract some of these extra calories.
Secondly, different food types affect insulin resistance. Some foods increase the risk and some foods reduce it. Try the Mediterranean diet, stick to low GI foods where possible, or ask a doctor or nutritionist for advice on what foods to eat.
Being overweight increases the chances of becoming insulin resistant.
People with excess fat around the waist and abdomen, in particular, are at higher risk of developing insulin resistance. This is because fat cells secrete hormones and other substances that may interfere with the processes of insulin.
Excess fat around the waist might also relate to chronic inflammation. This can trigger a wide range of health problems, including insulin resistance.
Not getting enough exercise can affect the way insulin regulates glucose. According to the American Diabetes Association, physical activity plays a vital role in keeping blood sugar levels steady.
Engage in light exercise after meals. Exercise causes the muscles to use up glucose without needing insulin. This reduces blood sugar levels.
Other risk and lifestyle factors
Sleep problems might increase insulin resistance.
Some other lifestyle factors that affect insulin resistance include:
- Smoking: This can impair insulin sensitivity as well as insulin production
- Sleep issues: Losing 1–3 hours of sleep per night can increase insulin resistance.
- Age: Being over 45 years of age might increase the risk of insulin resistance.
- Use of steroids: Taking this type of drug can increase insulin resistance by 60–80 percent depending on dose.
- Underlying health conditions: High blood pressure, previous episodes of stroke or heart disease, and polycystic ovarian syndrome (PCOS) can all increase a person's risk of developing insulin resistance.
- Hormonal disorders: Disorders that affect hormone production, such as Cushing's syndrome and acromegaly, can disrupt insulin sensitivity.
- Race: People of African-American, Hispanic, Native Alaskan, Indian, Hawaiian, or American, and Pacific Islander descent are at a higher risk of insulin resistance.
Insulin resistance means that the cells become less effective at absorbing glucose from the blood. It is common during prediabetes, the stage before type 2 diabetes.
Diet plays an essential role in preventing insulin resistance. Eating foods with a low GI and GL, as well as managing body weight and abdominal fat can reduce the risk. A mostly plant-based diet that is high in fiber and low in carbohydrate can help moderate the risk.
Eat more citrus fruits, tomatoes, and non-starchy vegetables, and avoid sugary snacks, processed goods, and starchy foods, such as corn and rice.
Body mass index (BMI) is one way of getting an overview of health and diabetes risk.
Does prediabetes always turn into diabetes?
A diagnosis of prediabetes does not mean that you will definitely advance to diabetes, though it is a high risk factor.
The good news is that prediabetes is reversible. Evidence shows that there is a 40–70 percent reduction in the risk of developing diabetes when a person makes and sustains healthy lifestyle changes.
These include reducing total carbohydrate intake, switching from processed carbs to high-fiber, low-GI carbs, losing weight, doing daily exercise, getting good quality sleep for 7–9 hours a night, and managing stress.Natalie Butler, RD, LD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.