Foods to Avoid While Taking Metformin

For those with type 2 diabetes, the body is unable to use insulin as effectively, leading to increased blood sugar levels. If left unchecked, this can lead to severe complications, such as heart problems, kidney disease, or eye damage.

Metformin is a medication that can help those with type 2 diabetes manage their blood sugar levels. However, combining metformin with a proper diet can help patients see even better improvements.

There are also certain foods that can interfere with the absorption of metformin or make its side effects worse. In this article, we will take a look at foods to avoid while taking metformin.

Table of Contents

What Is Metformin?

Metformin is a prescription medication used to treat type 2 diabetes. It can be used alone or with insulin.

Metformin belongs to the class of drugs called biguanides and helps to control the amount of glucose in the blood. It accomplishes this by decreasing the amount of glucose your body absorbs from food and the amount of glucose your liver makes. 

In addition, metformin helps to increase your body’s response to insulin, which is the natural substance produced by the pancreas that helps the body control how much glucose is in the blood. Those with type 2 diabetes often have insulin resistance, meaning their insulin does not work as effectively. However, metformin can help counteract this.

Metformin is not used to treat type 1 diabetes, though, as this is a condition where the body does not produce enough insulin. In contrast, with type 2 diabetes, the body is unable to use insulin effectively, which is why metformin can help.

How Should You Eat When Taking Metformin?

While metformin does not require a specific diet, the condition it is taken to address (type 2 diabetes) does.

Type 2 diabetes results when the body cannot use insulin properly, leading to high levels of glucose (sugar) in the blood. While metformin helps the body use insulin more effectively, it is vital to consume foods that support healthy blood sugar to see the best results.

What Foods to Avoid While Taking Metformin?

Simple and Refined Carbs

Foods with simple and refined carbs can cause your blood sugar levels to spike, which metformin may not be able to effectively help your body with. In addition, refined (processed) carbs typically have little fiber, which can cause blood sugar levels to rise quickly, similar to if you were to eat a food high in sugar.

Some foods to avoid within this category include:

  • white rice
  • white bread
  • white pasta
  • soda
  • candy
  • desserts

Avoiding these foods ensures that the metformin does not have to work harder to achieve the same result.

Saturated Fats

Saturated fats can increase inflammation in the body, which makes it hard to manage diabetes. Fatty foods also keep glucose elevated for extended amounts of time, which can also cause metformin to work harder than it should.

Some common sources of saturated fats include dairy products and red meats.

While cutting these products out of your diet completely is unnecessary, try opting for low-fat options when you can.

What Foods Should You Consider Including in Your Diet While Taking Metformin?

There are some foods you can take that will further help your body’s blood glucose control, making the effects of metformin even more pronounced.

Healthy Fats

Not all fats are bad, it’s just important to consume the correct kind. While saturated and trans fats should be avoided or limited, try to instead opt for unsaturated fats, which protect heart health and help fight inflammation.

Some great sources of healthy fats include:

  • nuts
  • fish
  • olive oil
  • avocado
  • seeds

Complex Carbohydrates

While you want to limit or avoid simple and refined carbohydrates, complex carbohydrates are a great substitution. This is because they contain fiber, which helps slow down your body’s conversion of carbs into glucose. While simple carbs result in a quick blood sugar spike, complex carbs produce more stable blood glucose levels.

In addition, complex carbohydrates also help promote healthy insulin levels, support gut health, and can aid in weight loss.

Some sources of complex carbohydrates include:

  • whole grain oats
  • brown rice
  • quinoa
  • whole-grain bread


In addition to complex carbohydrates, you will also want to get fiber from other sources because of its ability to promote steady blood sugar levels.

As a reference, try to aim for 25-30 grams of fiber each day, and you can find fiber in fruits, vegetables, and whole grains.

What Else Should You Avoid While Taking Metformin?

When taking metformin, it is important to avoid alcohol as it can interact with metformin and make it less effective.

Additionally, while it is important to eat enough fiber, it is crucial to avoid taking fiber supplements when on metformin because they can affect how well your body absorbs the drug.

How Should Metformin Be Taken?

Metformin can come in many forms, including a tablet, liquid, or extended-release tablet, all of which are taken by mouth.

The liquid is typically taken with food twice a day, while the regular tablet can be taken with food two or three times a day, depending on your doctor’s orders. The extended-release tablet is typically taken once a day with dinner.

Since metformin should be taken regularly, taking it at the same time(s) each day can help you remember to take it.

When taking extended-release tablets, it is important to swallow them whole; do not chew, split, or crush them.

When to See a Doctor?

If you have diabetes, it is recommended to talk to your doctor about dietary changes you should make to manage this disease better, even if you don’t take metformin.

For those looking for a quick and convenient way to connect with a doctor, DrHouse connects you with an online doctor in just 15 minutes who can prescribe medication and discuss what you should know when taking metformin, including how you can alter your diet to manage your diabetes.

Key Takeaways

Metformin is a drug that helps control the amount of sugar in the blood by decreasing the amount of glucose absorbed from food and making the body more responsive to insulin. Because of this, metformin can help those with type 2 diabetes and may be prescribed by itself or with insulin.

When taking metformin, it is crucial to evaluate your diet, as certain foods can help or hinder metformin’s ability to manage blood glucose levels. For example, try to avoid simple carbohydrates and saturated fats while incorporating more complex carbohydrates, fiber, and healthy fats.

Metformin must be taken with food, and its dosing instructions depend on what is prescribed by your doctor. Seeing the benefits of metformin requires proper adherence to the dosing and specific alterations to diet, which a doctor can help with.


  • Metformin: MedlinePlus Drug Information. (2022). 
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  • Gray A, Threlkeld RJ. Nutritional Recommendations for Individuals with Diabetes. [Updated 2019 Oct 13]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA):, Inc.; 2000-. Available from: 
  • Corcoran C, Jacobs TF. Metformin. [Updated 2022 May 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: 
  • Quagliani, D., & Felt-Gunderson, P. (2016). Closing America’s Fiber Intake Gap. American Journal Of Lifestyle Medicine, 11(1), 80-85. doi: 
  • Sami, W., Ansari, T., Butt, N. S., & Hamid, M. (2017). Effect of diet on type 2 diabetes mellitus: A review. International journal of health sciences, 11(2), 65–71. PMID: 28539866; PMCID: PMC5426415.

Content on the DrHouse website is written by our medical content team and reviewed by qualified MDs, PhDs, NPs, and PharmDs. We follow strict content creation guidelines to ensure accurate medical information. However, this content is for informational purposes only and not a substitute for professional medical advice, diagnosis, or treatment. For more information read our medical disclaimer.

Always consult with your physician or other qualified health providers about medical concerns. Never disregard professional medical advice or delay seeking it based on what you read on this website.

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