Metformin is a common medication used to treat type 2 diabetes. It helps lower blood sugar levels and increase the body’s response to insulin.
You do not need to avoid many specific foods while taking metformin.
However, the drug does not work without diet and lifestyle changes that also support healthy blood sugar.
In this article, we’ll explore the best foods to eat and foods to avoid while taking Metformin for type 2 diabetes.
Foods to Avoid While Taking Metformin
While metformin does not interact with many specific foods, alcohol and certain nutrients may make diabetes treatment less effective.
- Alcohol: Metformin interacts with alcohol, so avoid binge drinking or regular alcohol intake when on the medication. While infrequent, moderate alcohol is not likely to be problematic unless you have kidney or liver problems, talk to your healthcare provider before consuming alcohol with metformin.
- Simple and refined carbs: Metformin helps the body reduce blood sugar, but it doesn’t work effectively if you eat a lot of foods that make blood glucose levels spike. Refined or processed carbs have little fiber and can rapidly increase blood sugar levels. So can foods high in sugar. As much as possible, avoid white bread, white rice, white pasta, candy, soda, desserts, and snacks like chips or crackers. Eating foods that can spike your blood sugar will not necessarily make the metformin not work, however, it will increase the burden it has to work against.
- Saturated fat: Diabetes is a chronic condition that increases the risk of inflammatory disorders like cardiovascular disease. Saturated fats can increase inflammation in the body and may make it harder to lose weight or manage diabetes. They can also contribute to imbalanced lipids. Red meat and dairy products (milk, butter, cheese, etc.) are common sources of saturated fat. You don’t have to avoid all dairy, but focus on low-fat options. Fatty foods can also keep glucose elevated for longer periods of time.
- Trans fat: Many store-bought baked goods or restaurant fast foods contain trans fats. These are inflammatory and may increase the risk for heart disease.
- Too much sodium: Diabetes can increase the risk for hypertension and heart problems. Most Americans eat an excessive amount of salt, which can also increase the risk of high blood pressure. Aim for 2,300 mg of sodium per day or less.
Foods to Consider While Taking Metformin
In addition to taking metformin, some foods can help support blood glucose control.
- Complex carbohydrates: Unrefined grains such as brown rice, whole grain oats, whole-grain bread, and quinoa contain fiber. Fiber slows the rate at which your body converts carbs into glucose, leading to more stable blood glucose levels. It also helps promote healthy insulin and glucose levels, supports gut health, and may help with weight loss.
- Healthy fats: A low-fat diet is important, and the type of fat also matters. Fish, nuts, avocado, and olive oil all contain unsaturated fats, which help fight inflammation and protect heart health.
- Fiber: Most Americans don’t get enough fiber. This nutrient supports a healthy digestive tract, good blood sugar levels, and weight loss. Aim for 25-30 grams per day from whole grains, fruits, and vegetables. You can also try a fiber supplement if you struggle to eat enough fiber, but check with your medical provider. Don’t take fiber supplements at the same time as metformin, since they may change the way your body absorbs the drug.
- Lean proteins: Turkey, chicken, fish, and tofu are lean sources of protein, which can help control blood sugar and minimize saturated fat intake.
- Vegetables: Aim to fill half of your plate at each meal with non-starchy vegetables like broccoli, cabbage, asparagus, leafy greens, and cauliflower.
- Low-carb fruits: While all fruits contain beneficial nutrients, eating lower-carb fruits is better for glucose balance. For example, berries are low-carb and contain plenty of fiber.
When to Take Metformin
Your medical provider or pharmacist will tell you how to take metformin.
Immediate-release tablets are typically taken twice daily with meals, while extended-release tablets are taken once daily with food.
Should metformin be taken with food?
You should take metformin with food. Doing so can decrease the potential for side effects like diarrhea, nausea, gas, and bloating.
Precaution and Risks
Metformin carries a black box warning from the U.S. Food and Drug Administration.
This is the FDA’s most serious type of warning.
Rarely, metformin may cause a build-up of lactic acid in the body.
If the levels get too high, a serious, potentially fatal condition known as lactic acidosis can occur.
Lactic acidosis is a medical emergency.
Signs and symptoms can include flushing (sudden reddening), feelings of warmth on the skin, dizziness, nausea, vomiting, heart rate changes, and muscle pain.
If you or someone you care for develop these signs while taking metformin, get emergency medical care immediately.
Metformin may be unsafe for certain medical conditions, including:
- Kidney problems or disorders
- Metabolic acidosis
- Heart failure
If you take metformin, you will be asked to stop it temporarily before any surgical procedures or radiological testing.
The iodine contrast used for these can interact with metformin.
Metformin also has other potential drug interactions:
- Oral contraceptives
- Calcium channel blockers
- Coenzyme Q10
- Beta blockers
- Green tea
When to See a Medical Provider
If you have diabetes, whether or not you take metformin, your healthcare provider can answer questions about an appropriate diet.
They can also refer you to a registered dietitian or other experts who can work with you to create a personalized diet plan that supports healthy blood glucose levels and helps you reach other health goals.
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Frequently Asked Questions
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Nutritional Recommendations for Individuals with Diabetes. (2019).
Evolving Nutritional Therapy for Diabetes Mellitus. (2020).
Closing America's Fiber Intake Gap. (2017).
FDA SAFETY ANNOUNCEMENTS FOR METFORMIN - Metformin Use in Patients with Historical Contraindications or Precautions. (2016).
Metformin-associated lactic acidosis: Current perspectives on causes and risk. (2016).