8 Foods to Avoid While Taking Metformin

Medically Reviewed By : DR. ARJUN SUBASH KALASAPUR, MD (Pharmacology) November 29, 2023

Last updated on October 11th, 2023

Metformin is the first-choice medicine for type 2 diabetes; it is known to reduce the levels of blood glucose (safely).

Also, it’s both effective and well-tolerated and is considered the first-line treatment of diabetes, as per the American Diabetes Association (ADA).

Generally, Metformin does not create a problem for diabetic patients if they eat mindfully. But still, there are certain foods to avoid while taking metformin to ensure optimum effects and no complications.

Read this article to learn about foods to avoid while taking metformin.

What is Metformin?

Metformin 500 mg Tablet is a drug recommended for treating Type 2 diabetes, prediabetes, and insulin resistance. Of the total 30 million diabetics, 90 to 95% of them have Type 2 diabetes, according to the CDC. Metformin belongs to the class of medications called biguanides, which are drugs that prevent the liver from forming sugar. Metformin also reduces the amount of sugar the body absorbs from the food a person consumes and improves the body’s response to insulin.

Foods to Avoid While Taking Metformin

Foods to Avoid While with Metformin

The right dose of Metformin and diet can work wonders for a diabetes patient if balanced well. Below are some types of foods not to eat while taking Metformin:

1. Fats

Trans fats and saturated fats should be avoided while on metformin due to their potential negative impact on cardiovascular health.

Trans fats, often found in processed and fried foods, can raise bad cholesterol levels and increase heart disease risk. Saturated fats, commonly in red meat and full-fat dairy, can also raise bad cholesterol.

Since metformin is used to manage conditions like diabetes, maintaining cardiovascular health is crucial, making it advisable to limit these unhealthy fats for overall well-being.

Also Read: Metformin Side Effects: Common, Severe and Long Term

2. Simple And Refined Carbohydrates

When we eat simple and refined carbohydrates, like sugary foods and white bread, our body quickly turns them into sugar.

This sugar rushes into our bloodstream, causing our blood sugar levels to rise rapidly. Now, metformin is a medicine that helps keep our blood sugar levels steady, which is important, especially for people with diabetes.

But when we eat too many sugary and starchy foods, our blood sugar goes up a lot, and metformin might have a harder time controlling it. It’s like trying to stop a car that’s going really fast – it becomes more challenging.

So, by avoiding too many of these fast-acting carbs, we’re helping metformin do its job better. We’re making sure our blood sugar levels stay in a safe and steady range, which is good for our health, especially if we’re taking metformin to manage conditions like diabetes.

3. High Fiber Foods

There are some extremely high-fiber foods on the list of foods not to eat while taking Metformin. Consuming fiber in diabetes is generally a good idea as it slows down how fast sugar gets into our blood.

But it’s not really good if not consumed in moderation along with medicines like metformin. Fiber is thought to absorb certain medicines and reduce their concentration in the bloodstream.

If a person consumes huge quantities of fiber, the levels of Metformin might reduce. Keep the consumption of fibers below 30 grams per day.

Also Read: Normal Sugar Level For Women

4. Sodium

Another type of foods to avoid while taking metformin also include sodium. Avoiding excess sodium while on metformin is recommended due to potential interactions with blood pressure regulation. High sodium intake can elevate blood pressure, and metformin is commonly prescribed to manage conditions like diabetes.

Elevated blood pressure could exacerbate cardiovascular risks associated with these conditions. Additionally, excessive sodium might affect kidney function, which is monitored in metformin users.

Prioritizing a low-sodium diet supports overall cardiovascular health and complements metformin’s benefits in managing blood sugar levels, reducing the risk of complications, and promoting general well-being.

A person must avoid consuming an excess of sodium while a person is on Metformin. Keep the intake of sodium below 2300 milligrams per day.

5. Alcohol

A person must avoid huge amounts of alcohol since it enhances the risk of developing low blood glucose as well as lactic acidosis. Alcohol is found to prevent the liver from storing and liberating sugar.

Since diabetics already struggle to manage blood sugar levels, reducing the risk factor of alcohol intake is worth consideration. Drinking alcohol on an empty stomach may result in low blood glucose as the Metformin alcohol reaction can be worse.

This is true for individuals using insulin or other anti-diabetes medicines that enhance the levels of insulin. Metformin is found to amplify the quantity of lactate.

Lactate is the underlying compound of lactic acid. Research confirms that an excess of alcohol in combination with a thiamine deficiency may give rise to lactate accumulation. Alcohol and Metformin together might cause excessive lactic acid in the blood.

This may result in a severe condition, lactic acidosis. Overall, drinking in moderation is safe. Safe levels are one drink per day for females as well as 2 drinks per day for males.

6. Grapefruit

One study explored the grapefruit effects on Metformin. Researchers found that the participants who had both Metformin and grapefruit juice had a higher quantity of production of lactic acid as compared to the participants who had just Metformin. They might also have more weight gain.

It was also established that grapefruit juice enhanced the build-up of metformin in the liver. This then brought up an increase in lactic acid production. It was also concluded from the studies that drinking grapefruit juice may result in a greater risk of lactic acidosis in patients consuming Metformin.

7. Low-Carb Fruits

Incorporating low-carb fruits into your diet alongside metformin is advantageous due to their minimal impact on blood sugar levels.

These fruits, like berries (strawberries, blueberries, raspberries), apples, pears, cherries, and kiwi, are rich in fiber and nutrients, causing gradual sugar release. 

This aids in maintaining stable glucose levels, which is particularly important for individuals using metformin to manage diabetes or PCOS. 

The fiber content slows sugar absorption, reducing the risk of blood sugar spikes. Opting for low-carb fruits supports overall glucose control and complements the effects of metformin in regulating blood sugar.

8. Nuts And Seeds

Incorporating nuts and seeds into your diet while on metformin offers benefits due to their low glycemic index and healthy fats. These foods provide sustained energy, aiding in blood sugar control alongside metformin.

Examples like almonds, walnuts, chia seeds, and flaxseeds offer fiber, essential nutrients, and omega-3 fatty acids. They help stabilize glucose levels, promoting overall metabolic health.

Including nuts and seeds complements metformin’s effects by supporting steady blood sugar levels and enhancing the medication’s efficacy in managing conditions like diabetes or PCOS.

Also Read: Side Effects of Metformin

Foods To Avoid While Taking Metformin For PCOS

Foods To Avoid While Taking Metformin

Women with conditions like PCOS need to be extra cautious about what they eat, especially when they’re prescribed medications like Metformin.

It’s always a good idea to stick to a basic, healthy diet and avoid unnecessary junk. Here are some specific foods to avoid while taking metformin for PCOS:

Alcohol: The first in the list of foods to avoid while taking metformin for PCOS is alcohol. Drinking alcohol can make your blood sugar go down.

If you drink too much with metformin, it might drop even more. If you want a drink while using metformin for PCOS, just have one per day, not more. Drinking more during PCOS can lead to metformin alcohol reaction.

Sugary Drinks: Drinks like soda, sweet teas, and energy drinks have lots of sugar that can quickly make your blood sugar go up. If your body has trouble with insulin (a hormone), like in PCOS, it’s smart to skip these drinks. This way, metformin can do its job better and help fix the insulin issue.

Added Sugar Foods: Foods with lots of extra sugar can make insulin issues and PCOS problems worse. Doctors say it’s best to keep your added sugar under 25 grams per day.

Refined Grains: Refined grains are another addition to the list of foods to avoid while taking metformin for PCOS. Some grains lose the good stuff like nutrients and fiber, and these grains can quickly raise your blood sugar. If you’re taking metformin for PCOS, it’s wise to avoid these grains.

Fried Foods: If your tummy feels funny with metformin, fried foods might be the reason. Cutting down on them could help. Plus, it might help with weight, which can make insulin work better and improve PCOS symptoms.

Excess Salt: Having diabetes can make heart problems more likely. People worldwide often eat too much salt, which can raise blood pressure. It’s wise to aim for 2,300 mg of salt or less every day. This helps keep your heart and blood pressure in a healthier range.

Also Read: Metformin Alternatives: Different Diabetes Medications to Consider Instead of Metformin

How does grapefruit have an effect on Metformin?

Metformin does not get broken down by the same enzyme as the medicines listed above. It remains unprocessed by a person’s body and removed in the form of urine.

A study discussed the effects of grapefruit with Metformin in non-diabetic people. Few rats were exposed to grapefruit juice as well as Metformin. Others were exposed to only Metformin.

It was found that there was an increase in the amount of production of lactic acid in the people who were exposed to Metformin as well as grapefruit juice.

It was guessed that grapefruit juice increased the build-up of Metformin in the liver. This, sequentially, brought about an increase in lactic acid production. It is suggested that drinking grapefruit juice may cause an enhanced risk of lactic acidosis in people having Metformin.

Metformin and Alcohol

Generally, diabetics must moderate their alcohol consumption as alcohol impairs the liver’s ability to store and liberate sugar. This is a problem for diabetics as their bodies already fight to manage blood sugar. Furthermore, drinking alcohol on an empty stomach might bring about low blood sugar (hypoglycemia).

This alcohol-associated complication is more common in individuals using insulin or diabetes medicines that enhance insulin levels. Metformin does not enhance insulin levels. Hence, alcohol-induced hypoglycemia is less expected to take place in individuals who take it.

Metformin-Related Lactic Acidosis

When the body utilizes sugar as energy, lactic acid gets released. Metformin enhances the amount of lactate, the basic compound present in lactic acid in the bloodstream. This is classically a benign effect, however, as per a research study, an excessive intake of alcohol in addition to a thiamine (vitamin B1) deficiency might lead to the accumulation of lactate. This combination of Metformin and alcohol might bring about an excess of lactic acid in the blood, a deadly condition that might give rise to lactic acidosis, in individuals having acute or chronic alcohol abuse.

Metformin-related lactic acidosis (MALA) occurs rarely however, and is possibly dangerous. While the risk of lactic acidosis for diabetic people is low, his or her risk is greater if a person has congestive heart failure or impaired liver or kidney function.

If a person is using Metformin, they must drink alcohol in moderation. “Moderation” signifies:

  • One drink per day for females
  • Males above 65 years of age
  • Two drinks per day for males below the age of 65 years.

However, discussing the intake of alcohol with a healthcare provider as a no-alcohol lifestyle can be healthiest for him or her.

Book your consultation with a Diabetes expert now. Our Diabetes Specialists assist in transforming lifestyles and deal with the emotional issues that this condition can bring. With a unique mix of interconnected technology and human touch, you will be connected to our diabetes-focused holistic support throughout the day.

Also Read: Symptoms of Type 2 Diabetes

Foods To Include In A Metformin Diet

Foods To Include In A Metformin Diet

Below are 5 foods a person can add to their Metformin diet.

1. Complex carbs:

These carbohydrates are derived from fruits, veggies, whole grains like brown rice as well as whole-grain bread. They have more fiber and this increases their difficulty in getting metabolized.

This then slows the liberation of sugar into the bloodstream. If a person is having complex carbohydrates, it is a must to keep a track on his or her overall carb consumption.

This is significant as carbs directly affect blood glucose levels.food to avoid when taking metformin.

2. Lean Protein:

Incorporating lean protein into your metformin diet is beneficial as it helps stabilize blood sugar levels and promotes satiety. Proteins like chicken, fish, tofu, and legumes have a low glycemic impact, reducing sugar spikes.

This synergizes with metformin’s effects, aiding in glucose management for conditions like diabetes.

3. Healthy fats:

Including healthy fats in your metformin diet offers benefits by providing sustained energy and aiding blood sugar regulation.

Fats like avocados, nuts, seeds, and olive oil have a minimal impact on blood sugar levels while supporting nutrient absorption.

This complements metformin’s effects, promoting stable glucose levels and overall metabolic health.

4. Non-Starchy Veggies:

Eating non-starchy veggies with Metformin is a clever idea because they’re low in carbs and won’t cause rapid sugar spikes. Metformin helps regulate blood sugar, and these veggies support its role by not adding too much sugar.

Imagine them as a team working together to keep sugar levels steady. This harmony is crucial for overall well-being, particularly when managing conditions like diabetes or PCOS. It’s like having a strong backup for Metformin’s efforts.

Also Read: Gliclazide + Metformin Tablets to Control Your Blood Sugar Levels

5. Moderate Fiber Consumption:

Even though it is suggested not to have lots of fiber, moderate fiber consumption might actually be useful. This is due to the reason that fiber helps in regulating the levels of blood sugar. The average consumption of fiber is between 25 and 30 grams per day.

6. Low-Carb Fruits

Incorporating low-carb fruits into your diet with metformin is advantageous due to their minimal impact on blood sugar. Berries (strawberries, blueberries, raspberries), apples, pears, cherries, and kiwi are fiber-rich and release sugars gradually.

This helps stabilize glucose levels, vital for managing diabetes or PCOS with metformin. The fiber content curbs sugar absorption, lowering spike risk, supporting glucose control, and synergizing with metformin’s effects.

7. Nuts And Seeds

Adding nuts and seeds to your metformin diet provides low-glycemic, energy-sustaining benefits. Varieties such as almonds, walnuts, chia seeds, and flaxseeds supply fiber, nutrients, and omega-3s, aiding glucose stability.

This complements metformin’s effects, enhancing its efficacy in managing conditions like diabetes and PCOS.

Also Read: Glimepiride and Metformin Tablet Uses, Side Effects, Dosage & Interaction

Other Things to Avoid While on Metformin

Consumption of a few medicines while using Metformin might enhance the risk of developing lactic acidosis. Thus, it is essential to discuss with the concerned doctor if a person is taking any of the following medicines:

  • Diuretics like acetazolamide
  • Antipsychotic medications including chlorpromazine
  • Anticonvulsants like topiramate and zonisamide
  • Oral contraceptives
  • Corticosteroids like prednisone
  • Antihypertensives such as amlodipine

A person must also avoid having high-fiber foods after consuming this drug. This is because fiber can bind to medicines and reduce their concentration. Metformin hydrochloride tablets ip levels reduce when consumed with huge quantities of fiber (more than 30 grams per day).

Also Read: How to Use a Glucometer to Monitor Your Blood Sugar level?

Drugs To Avoid While On Metformin

Drugs To Avoid While On Metformin

While metformin is generally well-tolerated, there are certain medications and substances that might interact with it and require caution or avoidance. Always consult a healthcare professional before making any changes to your medication regimen.

Contrast Agents: If you’re having a medical procedure that involves contrast agents for imaging, such as a CT scan with contrast dye, your doctor might advise temporarily stopping metformin. This is to prevent a rare condition called lactic acidosis, although the risk is low.

Alcohol: Excessive alcohol consumption can affect blood sugar levels and metabolism, potentially interacting with metformin. Moderation is key, but it’s best to consult your doctor about alcohol use while on metformin.

Certain Blood Pressure Medications: Some medications for high blood pressure, like beta-blockers and angiotensin-converting enzyme (ACE) inhibitors, might affect blood sugar levels. Your doctor can help you manage these medications alongside metformin.

Some Diuretics: Certain diuretics (water pills) could impact kidney function and potentially interact with metformin. Close monitoring is important if you’re prescribed both types of medications.

Cimetidine (Tagamet): This medication, used for acid reflux and ulcers, can slow down metformin’s removal from the body, possibly leading to higher metformin levels. Your doctor might adjust your metformin dosage if you need to take cimetidine.

Certain Antidepressants: Some antidepressants, particularly monoamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs), might influence blood sugar levels and interact with metformin. Discuss potential interactions with your doctor.

Medications Impacting Kidney Function: Since metformin is primarily eliminated through the kidneys, medications that affect kidney function might impact metformin’s safety and effectiveness. Always inform your doctor about any kidney-related medications.

Other Diabetes Medications: Combining multiple diabetes medications, including different types of oral medications or insulin, should be done under medical supervision to avoid adverse interactions.

Iron Supplements: Taking iron supplements alongside metformin might decrease the absorption of both substances. If iron supplementation is necessary, discuss timing and dosage adjustments with your doctor.

Vitamin B12 Supplements: Long-term metformin use can potentially lead to decreased vitamin B12 absorption. Some individuals might need B12 supplementation, but this should be guided by a healthcare professional.

Insulin: When insulin and metformin are used for Type 1 or Type 2 diabetes together, they can lower blood sugar (hypoglycemia) risk. Type 2 diabetes patients might use both, needing cautious monitoring.

Signs like fast heartbeat, hunger, and shakiness indicate hypoglycemia. Swiftly treat with glucose tablets or juice. Keep these on hand and discuss glucagon with your doctor for raising blood sugar quickly. Don’t ignore hypoglycemia; acting fast is important.

Note: Remember, personalized medical advice is crucial. Always inform your healthcare provider about all medications, supplements, and medical conditions you have, to ensure safe and effective use of metformin.

Also Read: Metformin 500 MG Tablet: Know All About Generic Medicine For Diabetes Patients

Few Diet Guidelines for Diabetics are as Follows:

  • Add carbs derived from veggies, fruits, and whole grains. Make sure to monitor carb intake, as this would directly influence blood sugar.
  • Avoid food rich in saturated and trans fats. In its place, have fats from fish, nuts, and olive oil.
  • Consuming 25 to 30 grams of fiber every day might aid in regulating blood glucose levels.
  • Avoid sodium. Try to have less than 2,300 milligrams each day.

Look at the Overall Diet

Metformin reduces the levels of blood glucose.  It is much less efficacious when it’s not followed by a balanced, healthy diet. Try avoiding or limiting foods causing high sugar:

  • to derive the most profit from any diabetes medicine
  • to improve a person’s overall health.

Read More: Know About Insulin Therapy for Type 2 Diabetes

Major culprits when it comes to high blood sugar:

  • foods consisting of simple carbs (sodas, candies, desserts)
  • refined carbs (white bread, white rice, pasta)

As an alternative, choose complex carbs such as brown rice and whole-grain bread. These carbs have a large amount of dietary fiber. Thus, they are harder for the body to metabolize. This slows the liberation of sugar into the bloodstream. In addition:

  • Ensure to add lean proteins (such as turkey, fish, and tofu)
  • Fill half of the plate with non-starchy veggies at each meal. These can be broccoli and leafy greens.

This would help in slowing down the carb metabolism.

Also Read: Metformin Oral: Uses, Side Effects, Dosage & Interactions


What should I eat for breakfast while on metformin?

A suitable breakfast while on metformin consists of a balance of carbs, protein, and healthy fats. Opt for choices like oatmeal topped with berries and nuts, Greek yogurt with fruit, or whole-grain toast with eggs and avocado. Avoid sugary cereals and pastries to help stabilize blood sugar levels. Customize your breakfast to your preferences.

What can I eat while taking metformin for PCOS?

When using metformin to manage PCOS, focus on foods that address insulin resistance. Choose complex carbs, lean proteins, and fiber-rich options. Include fruits, vegetables, nuts, and whole grains. Staying hydrated is vital. For personalized guidance, consult a healthcare professional or dietitian to tailor your diet to your needs.

What is the best diet while taking metformin?

The optimal diet while on metformin involves a balanced approach. Prioritize vegetables, lean proteins, whole grains, and healthy fats. Minimize processed foods, sugary snacks, and excessive carbs. Portion control and regular meals can help stabilize blood sugar levels and enhance metformin’s effectiveness.

Can you drink milk while taking metformin?

Drinking milk while on metformin is usually safe. However, consuming excessive dairy might impact the medication’s absorption. To prevent potential interactions, separate metformin doses and milk consumption. Always consult your healthcare provider for personalized guidance on managing your diet alongside metformin.

What is lactic acidosis metformin?

Lactic acidosis is a rare but serious condition marked by elevated lactic acid levels in the blood. While lactic acidosis is associated with metformin in some concerns, it’s primarily linked to factors other than the medication itself, such as kidney impairment. Metformin remains generally safe when used as prescribed.

How does metformin cause lactic acidosis?

Metformin itself rarely causes lactic acidosis. This condition is more commonly linked to factors like kidney problems, infections, or severe medical conditions. Metformin’s connection to lactic acidosis prompted precautions for patients with kidney issues. Regular kidney function monitoring helps ensure safe metformin use.

Can you drink alcohol with metformin?

While moderate alcohol consumption might not directly interact with metformin, it’s generally recommended to limit alcohol intake. Alcohol can influence blood sugar levels and metabolism, potentially affecting how the medication works. Consult your healthcare provider for personalized advice on alcohol consumption.

What foods should you avoid when taking metformin?

When on metformin, it’s advisable to steer clear of high-carb and sugary foods. Avoid processed sweets, sugary drinks, and excessive starchy foods. Opt for a balanced diet rich in vegetables, lean proteins, and whole grains to support the medication’s effectiveness.

Should you drink a lot of water when consuming this medicine?

Metformin must be consumed with meals to assist lower stomach or bowel side effects that might happen during the initial few weeks of treatment. The tablet or extended-release tablet must be taken whole with a full glass of water. Avoid crushing, breaking, or chewing the tablet.

What occurs if a person has glucose on metformin?

There are no food products that are off-limits with the medicine. On the other hand, a person must be having a healthy diet to help regulate diabetes. When a person consumes glucose and metformin, body would have to work harder to reduce the blood sugars.

Is cucumber water safe for diabetic people?

For diabetic people, cucumber might be a useful addition to their diet to moderate blood glucose levels more efficiently.

Does milk influence the effects of metformin?

Metformin seems to be “safe” during breastfeeding due to low infant exposure. The rare concentration-time profile for the medicine in milk proposes that the transfer of metformin into milk is not uniquely based upon passive diffusion.

Is it safe to have coffee while consuming Metformin?

Caffeine gets broken down by the body to remove it. Metformin may reduce how rapidly the body breaks down caffeine. Metformin when consumed in combination with caffeine can enhance the effects and side effects of caffeine.

Last Updated on by Dr. Damanjit Duggal 


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