Everyone with type 1 diabetes and some with type 2 diabetes requires insulin to stay healthy. Roughly 7.4 million Americans use insulin to treat their diabetes condition. So, does insulin cause weight gain for this portion of the population?
Although insulin enables many diabetes patients to live normal lives, insulin does have some side effects.
This article will explore if weight gain is one of them. Let’s start with a summary answer.
Does insulin cause weight gain? Insulin is a hormone that regulates the absorption of glucose. And many users of insulin have experienced weight gain as a common side effect. Insulin causes weight gain when the cells absorb too much glucose, which is then converted into fat. A dietician can help you make healthier lifestyle changes to control the weight gain.

Now that we’ve got a brief overview, it’s time to head into the details and explore further.
Let’s start by recapping exactly what insulin is and why it might be likely to add unwanted weight gain.
What is Insulin?
Insulin is a hormone produced by the pancreas for the purpose of allowing cells to uptake glucose from the bloodstream. Think of insulin as the key that unlocks cells to allow the liver, muscle, and fat cells to pick up glucose.
Once glucose has been picked up by the cells, the body can then use the glucose as energy. Any glucose that is not used for energy is stored to be used for energy later.
Why do some diabetics gain weight?
Recent research in the U.K, a study by Prospective Diabetes (UKPDS), discovered that the average person with type 2 diabetes gained, on average, around nine pounds during their first three years using insulin.
You see, the link between insulin and weight gain isn’t necessarily directly correlated with the insulin. It is more so correlated with the types of foods you are eating and the amount of calories you are burning daily.
When you consume more glucose than you burn in a day, it gets stored in the liver as glycogen. It is then converted into fatty acids and circulated throughout the body and stored as fat.
This process also explains why many patients that have diabetes and chronic hyperglycemia begin to experience weight loss.
Weight loss due to lack of insulin
We may ask “Does insulin cause weight gain?”, but what about weight loss? When someone is suffering from hyperglycemia and doesn’t have enough insulin circulating in their bloodstream, they will begin to experience some weight loss. This is because their cells are not able to uptake glucose, which prevents the body from being able to store glucose for energy.
Thus, the person is burning through their glycogen stores, which causes weight loss.
Excess glucose and nutrients are often expelled through urine. This can lead to kidney damage if left untreated.
This what I experienced with the onset of my diabetes condition. I was unaware of what was occurring in my body and didn’t know that my pancreas had stopped producing insulin. I experienced rapid weight loss, severe dehydration, and exhaustion. All signs of losing my glycogen stores and not being able to use glucose in my bloodstream for energy.
However, once I was diagnosed and put on an insulin regimen, I began to regain my weight. The cells in my body were able to start picking up glucose again due to the impact of insulin.
Is all insulin weight gain bad?

Like my experience described above, most people diagnosed with type 1 diabetes will likely gain some weight as soon as they start using insulin. This initial weight gain is generally healthy, as your body is getting hydrated again and able to absorb nutrients from the foods you are eating.
However, some weight gain from insulin can be unhealthy. For example, giving yourself too much insulin can lead to severe hypoglycemia, which requires you to consume excess carbohydrates. Excess carbohydrates over time can lead to unnecessary weight gain.
So is there a way you can manage any excess insulin-induced weight gain? Let’s find out below.
Does insulin cause weight gain? How to manage
Here are some ways you can better control weight gain potentially caused by insulin.
Stay active
Staying physically active and exercising regularly helps improve your insulin sensitivity and also burns calories. Burning about the equivalent amount of calories you consume in a day is crucial for maintaining a healthy weight and preventing weight gain.
Staying active can lower your insulin needs for a period of time also.
It is important to lower your insulin doses as needed around exercise. This prevents low blood sugars. In turn, you will not need to consume excess carbohydrates to treat lows.
Related: Diabetes and Exercise.
Research different insulin types regarding weight gain
You may be able to avoid having your insulin cause weight gain by looking at the type of insulins you’re using.
For example, once-daily Levemir used by people with type 2 diabetes causes less weight gain and less frequent hypoglycemia than NPH insulin.
The same may be true when using Lantus, Basaglar, Toujeo, and Tresiba.
When asking, “does insulin cause weight gain?” it may help you compare some of these options and read similar articles to further improve your knowledge. Here are some of our diabetes resources that may help you.
- What are the types of insulin?
- Lantus vs Basaglar
- Toujeo vs Basaglar
- Can insulin make you tired?
- Taking a break from your insulin
- Pros and cons of insulin pumps
In type 1 diabetes, individuals do often eat less when using Levemir compared to Lantus, which can lead to less weight gain.
Type 1 sufferers can lower basal doses to combat weight gain
Do you have an insulin pump and wonder whether using your pump and insulin cause weight gain? Those who have type 1 diabetes and use an insulin pump may be able to limit their risk of weight gain by lowering their basal rate and increasing their mealtime bolus.
According to a study of two groups of people with diabetes, weight gain was associated with the group with a higher basal rate and lower bolus ratio.
This may be due to the increased risk of hypoglycemic events associated with a high basal rate. As mentioned before, hypoglycemic events lead to the unwanted consumption of carbohydrates.
Therefore readjusting your insulin ratios may prevent insulin-associated weight gain. However, you should not make any adjustments to your insulin therapy without first consulting your doctor.
Does insulin cause weight gain? Healthy living combats diabetic weight gain
Choosing a healthy lifestyle that includes adequate physical activity, a healthy diet, and stress reduction can help you lose weight.
Maintaining a healthy diet is crucial for those with diabetes looking to prevent weight gain. Eating foods that do not require high insulin doses and prevent dramatic spikes in blood sugar will be beneficial for weight management.
It’s worth understanding that weight loss and maintaining a healthy weight will also help your insulin work better.
When insulin works better, your insulin needs reduce, which helps prevent low blood sugar and an increased chance of weight gain. So, this is a healthy cycle to try to adopt.
One of the best ways to start on the road to a healthier lifestyle is to meet with a registered dietitian who will have specialties in diabetes and meal planning.
Related: Is a Plant-Based Diet for Diabetes Beneficial?
Final Thoughts on the important question, “Does insulin cause weight gain?”
Can insulin cause weight gain? Yes, however it’s important to remember: keeping your weight down for anyone can prove to be a struggle. Couple this with diabetes, and it can be a much greater challenge.
Be sure to consult with your doctor and other relevant practitioners and sources to ensure you have both the information and understanding to combat your weight. Does insulin cause weight gain? Perhaps, but there are things you can do.
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