Type 2 diabetes develops when a person has insulin resistance. This means the body is no longer sensitive to insulin and cannot use it correctly. Losing weight may cause insulin to work more effectively for various reasons.

When insulin resistance starts, there are no signs and symptoms of diabetes, and blood sugar levels are normal.

Excess weight appears to increase the risk of developing insulin resistance and diabetes. Therefore, losing weight may help a person prevent these conditions.

According to the Centers for Disease Control and Prevention (CDC), more than 88 million people in the United States have prediabetes, while more than 34 million have diabetes. The majority of the latter group had type 2 diabetes, which results from insulin resistance.

In this article, we look at the link between insulin resistance and excess weight. We also explain how losing weight might prevent or reverse insulin resistance.

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When a person eats, the body absorbs nutrients from the food, including carbohydrates. During digestion, it converts carbs into glucose, or sugar. This enters the body’s cells to provide them with energy.

Insulin is a hormone that comes from the pancreas. It enables the blood sugar to move out of the blood and into the body’s cells.

When a person has insulin resistance, their cells stop responding to insulin in the usual way. This loss in sensitivity to insulin means that they begin to lose the ability to take in glucose.

In response, the pancreas boosts its insulin production so that glucose can continue to enter the cells. At first, this will help. The cells will have energy, and blood sugar levels will not rise.

However, as the cells’ resistance to insulin increases, the pancreas needs to produce more and more insulin. Eventually, it becomes unable to create enough insulin to move the glucose out of the blood and into the cells.

Diagnosing prediabetes

When blood sugar reaches higher than normal levels, a doctor may diagnose prediabetes.

Typical fasting blood sugar levels are:

  • Normal: Under 100 milligrams per deciliter (mg/dl)
  • Prediabetes: 100–125 mg/dl
  • Diabetes: 126 mg/dl and above

A doctor can test a person’s fasting blood glucose level, or an individual can check their glucose levels at home.

Insulin resistance does not typically cause any symptoms in its initial stages. However, a person may experience acanthosis nigricans, which can be a warning sign of insulin resistance.

Other health problems will appear in time unless a person takes action to treat the underlying cause of insulin resistance.

A person who has risk factors for diabetes may have insulin resistance without knowing it. Even if their blood sugar levels are normal, they should take steps to prevent diabetes.

Scientists do not know what causes insulin resistance. However, the following factors appear to play a role:

  • excess weight or obesity
  • excess fat around the abdomen
  • low levels of physical activity

Taking action in the early stages can prevent or reverse prediabetes. If a person does not take action, the body will not be able to produce enough insulin, and there will be too much glucose in the blood.

In time, as this glucose travels around the body, it can damage the blood vessels, nerves, and body organs, leading to severe and life threatening complications.

Research has found that a weight loss of 5–7% is enough to reduce the risk of diabetes.

For a person with diabetes or a high risk of diabetes, reaching and maintaining a moderate weight can help reduce the risk of insulin resistance, prediabetes, diabetes, and the health complications that can result.

People with insulin resistance, prediabetes, or a high risk of diabetes may benefit from long-term dietary and lifestyle strategies. A “crash diet” will not reduce insulin resistance.


The CDC’s National Diabetes Prevention Program emphasizes eating more healthful foods and doing at least 150 minutes of physical activity each week.

Exercising can help the body use insulin effectively. This can help to reduce insulin resistance.

Regular exercise can also reduce the risk of several conditions associated with diabetes, such as high blood pressure and cardiovascular disease.


Choosing healthful foods that include plenty of fresh fruits and vegetables, being mindful of portion sizes, and moderating carbohydrate intake are three of the most important factors in a sustainable, healthful diet.

Each person’s dietary requirements will be different, so a personalized approach is typically best. However, several diet plans may help people lose weight and reduce insulin resistance.

The DASH eating plan, which the National Institutes of Health (NIH) developed, is a healthful, long-term diet. DASH stands for “Dietary Approaches to Stop Hypertension.”

The diet does not focus on calorie control. Instead, it encourages people to eat:

The DASH diet is more suitable for long-term application than many calorie-controlled diets. This dietary approach also provides high fiber intake, which helps manage blood sugar levels by slowing the absorption of carbohydrates and reducing the need for insulin.

Other diets that may help people manage insulin resistance and lose weight are

A person making changes to their diet should always consult a medical professional before doing so.

Click here to learn more about how diet can help with insulin resistance.

Weight loss and a healthful diet are important ways of reducing the chance of developing insulin resistance. However, adding other strategies will lower the risk further.

Quitting smoking

Some studies have suggested that regular use of tobacco products may increase the risk of diabetes and insulin resistance. Others, however, have not found evidence of a direct link.

A 2016 study looking at the data of nearly 6,000 people concluded that there may not be a direct link between smoking and insulin resistance. However, it is still thought to possibly play a role in causing diabetes in combination with other factors.

Smoking is a risk factor for heart disease, lung infections, and other health conditions that are also complications of diabetes. Smoking can worsen these issues too.

For this reason, a person with insulin resistance or a high risk of diabetes should quit smoking if necessary and avoid secondhand smoke where possible. A doctor can help a person find resources and strategies to make quitting easier.

Learn more about quitting smoking here.

Vitamin D

Some research has found that people with diabetes are more likely to have low vitamin D levels.

However, there is no evidence that taking vitamin D supplements can prevent diabetes or prediabetes. In a 2018 study, researchers found that taking vitamin D supplements did not affect blood sugar levels in people with well-managed diabetes.

The Office of Dietary Supplements recommends that people ages 1–70 years consume 600 international units (IU) of vitamin D a day from dietary sources.

While sunlight is by far the most concentrated source of vitamin D, dietary sources include:

People should talk with their doctor about whether vitamin D supplementation is appropriate for them.

Learn more here about vitamin D and its sources.


Insufficient or poor-quality sleep can increase a person’s risk of developing insulin resistance and type 2 diabetes.

The authors of a 2015 study noted that for people with diabetes, sleep is “an additional lifestyle behavior, important for metabolic health and energy homeostasis.”

Getting plenty of sleep each day can help regulate the hormones that play a role in hunger and reduce the risk of glucose metabolism dysfunction.

Learn more about the importance of sleep here.


Some people need medication to help improve insulin sensitivity, especially when dietary and lifestyle changes have not been effective. Doctors often prescribe metformin or other medicines for this purpose.

Learn more here about the medications available for managing diabetes.

A diagnosis of insulin resistance does not automatically mean that a person has diabetes. However, without intervention, diabetes can develop.

Achieving and maintaining a suitable target weight can reduce the risk of developing type 2 diabetes.

People with insulin resistance, prediabetes, or diabetes should ask their doctor about a suitable weight-loss plan.

Healthful eating habits are crucial for losing weight, maintaining a healthy weight, and preventing insulin resistance.

It can be helpful to connect with other people who may be facing similar issues. Bezzy T2D is a free app that provides support through one-on-one conversations and live group discussions with others living with type 2 diabetes. Download the app for iPhone or Android.