Insulin and weight gain: Keep the pounds off

Insulin and weight gain often go hand in hand, but weight control is possible. If you need insulin therapy, here's how to minimize — or avoid — weight gain.
By Mayo Clinic Staff
Jan. 21, 2026

People who take insulin often gain weight. Insulin is a hormone that regulates how the body absorbs sugar, also called glucose. The weight gain can be frustrating because keeping a healthy weight is important to manage your diabetes. The good news is that you can maintain your weight while taking insulin.

The link between insulin and weight gain

When you take insulin, sugar can enter your cells. This makes the sugar levels in your blood go down. This is the goal of treatment.

But if you take in more calories than you need to keep a healthy weight, your cells will get more sugar than they need. This happens in people who don't have diabetes, too. How many calories you need depends on how active you are. Sugar that your cells don't need to use becomes fat.

Avoid weight gain while taking insulin

Eating healthy foods and being physically active most days of the week can help you not gain weight. The following tips can help you keep the pounds off:

  • Count calories. Eating and drinking fewer calories helps you prevent weight gain. Keep fruits, vegetables and whole grains in your refrigerator and pantry. Plan for every meal to have the right mix of starches, fruits and vegetables, proteins, and fats. Generally, recommended meals would include half nonstarchy vegetable, one-quarter protein and one-quarter of a starch, such as rice, or a starchy vegetable, such as corn or peas.

    Shrink the sizes of your portions and don't take second helpings. Drink water instead of high-calorie drinks. Talk to your healthcare professional, nurse or a dietitian about how to plan meals and where to find resources.

  • Don't skip meals. Don't try to cut calories by skipping meals. When you skip a meal, you're more likely to make unhealthy diet choices at the next mealtime because you're too hungry. Skipping meals also can cause low blood sugar levels if you don't adjust your insulin dose.

  • Be physically active. Physical activity burns calories. A recommended goal for most adults is at least 150 minutes a week, or 30 minutes five days a week, of moderately intense aerobic activity. Also aim to do muscle-strengthening exercises at least two times a week. Aerobic activities can include walking, bicycling, water aerobics, dancing or gardening. Talk with your healthcare professional about activities and exercises that are right for you.

    Also, ask your health professional how to handle exercise. Physical activity helps your body use insulin more efficiently. Depending on how much exercise you're planning on doing, you may need to cut back on your insulin dosage or have a snack. It's possible for your blood sugar to drop even hours after exercise.

  • Ask your healthcare professional about other diabetes medicines. Some diabetes medicines that help regulate blood sugar levels may help you lose weight and lower your insulin dosage. Examples of these medicines include metformin (Fortamet, Glumetza, others), exenatide (Byetta), liraglutide (Victoza, Saxenda), dulaglutide (Trulicity), sitagliptin (Januvia), saxagliptin (Onglyza), canagliflozin (Invokana), dapagliflozin (Farxiga), empagliflozin (Jardiance) and pramlintide (Symlin). Ask your health professional if these or other medicines should be part of your diabetes treatment plan.
  • Take your insulin only as directed. Don't skip or reduce your insulin dosages to stop weight gain. Although you might lose pounds if you take less insulin than prescribed, the risks are serious. Without enough insulin, your blood sugar level will rise — and so will your risk of diabetes complications.
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