One consequence of taking long-term medications for a chronic disease like diabetes is that you must consider your "long-term" dietary choices to maximize the medication's effectiveness and minimize its potential side effects.

The good news is that Metformin is widely tolerated and can go with many healthy food options. In fact, no food is entirely off-limits if you're taking Metformin. However, certain diets (especially when taken in excess) can alter the drug's effectiveness in managing blood glucose levels.

Foods to Avoid While Taking Metformin

  • Alcohol
  • Saturated fats
  • Refined carbs and sugar
  • Sodium


While a moderate amount of alcohol consumption poses little or no risk, drinking in large quantities every day while taking Metformin will reduce the effectiveness of the medication and increase the risk of potentially life-threatening complications like vitamin B-12 deficiency and lactic acidosis (a condition caused by an increase in lactic acid in the blood).

Consuming alcohol also poses an increased risk of hypoglycemia (low blood sugar) for individuals with diabetes. When combined with Metformin, a medication that also lowers blood sugar levels, the risk of experiencing low blood sugar is further amplified.

To ensure your safety and the drug's efficacy, it's advisable to limit or avoid alcohol altogether. Opt for healthier beverage alternatives such as water, herbal tea, or sugar-free drinks.

Refined carbs and sugar

Beverages high in simple and refined carbs can quickly increase blood sugar levels and potentially interfere with the effectiveness of Metformin. It's best to avoid regular intake of soda, fruit juices, energy drinks, and sweetened teas. Also, avoid white bread, white rice, pasta, candy, and snacks like chips or crackers. These foods contain little fiber and can rapidly raise blood sugar. The faster your blood glucose levels increase, the higher your Metformin dosage's workload, making it harder to manage blood sugar levels.

Saturated fats

While moderate amounts of healthy fats are generally acceptable, excessive consumption of high-fat foods can reduce the absorption of Metformin. In addition, saturated fats can increase inflammation and insulin resistance in the body, making it harder to lose weight and manage blood sugar levels. Fatty foods can also lead to persistent high blood sugar levels, posing long-term complications.

Red meats, cheese, butter, and milk are common sources of saturated fats. However, it is not necessary to completely eliminate dairy from your diet. Opting for lower-fat alternatives is an excellent strategy to ensure an adequate protein and calcium intake without excessive saturated fat content.


The average American consumes excessive salt, averaging around 3,400 mg of sodium per day. However, the Dietary Guidelines for Americans advise that the average adult limit their sodium intake to no more than 2,300 mg daily, equivalent to approximately one teaspoon of salt.

High sodium intake poses a significant risk for individuals with diabetes, as it can contribute to high blood pressure and heart disease, which are already heightened concerns for people with diabetes.

The primary source of sodium in the American diet is processed and refined foods, including restaurant meals. By preparing more meals and snacks at home, you have an easy and effective way to reduce your salt intake. Cooking your own meals gives you greater control over the amount of salt you add to your dishes, making it easier to stay within the recommended sodium limits.

Foods to Include in Your Diet While on Metformin?

Eating a balanced and nutritious diet while taking Metformin will not only lower blood sugar levels but also improve your overall health. Here are some foods you can include in your diet while on Metformin:

Complex Carbs

Complex carbohydrates are critical to a healthy diet, providing sustained energy and essential nutrients. These carbohydrates contain lots of dietary fiber and are digested more slowly, leading to a more gradual release of glucose into the bloodstream and better diabetes management. Unfortunately, according to national consumption surveys, only approximately 5% of the US population meets the recommended fiber intake. Inadequate fiber consumption has been identified as a major public health concern.

Some sources of complex carbs include:

  • Whole grains: Eat brown rice, quinoa, whole wheat bread, oats, and whole grain cereals.
  • Legumes: Incorporate beans, lentils, peas, and other legumes into your meals for added fiber and protein.
  • Sweet potatoes: These nutritious root vegetables are a great source of complex carbs, fiber, and various vitamins and minerals.

Nonstarchy Vegetable

Nonstarchy vegetables are low in calories and carbohydrates but rich in fiber, vitamins, and minerals. These vegetables are excellent choices for your diet due to their high nutrient density and minimal impact on blood sugar levels. Some examples of nonstarchy vegetables include:

  • Leafy greens: Spinach, kale, Swiss chard, and arugula are packed with essential nutrients and are versatile for use in salads, stir-fries, or smoothies.
  • Peppers: Bell peppers, whether red, green, or yellow, are flavorful and rich in antioxidants.
  • Cruciferous vegetables: Broccoli, cauliflower, Brussels sprouts, and cabbage offer an abundance of fiber and vitamins while adding variety to your meals.

The American Diabetes Association recommends choosing fresh, frozen, or canned vegetables and vegetable juices without added sodium, fat, or sugar.

Healthy Fats

Incorporating healthy fats into your diet is crucial for overall health and can help improve insulin sensitivity. Opt for the following sources of healthy fats:

  • Olive oil: Use extra virgin olive oil as your primary cooking oil or for dressings to benefit from its anti-inflammatory properties.
  • Nuts and seeds: Almonds, walnuts, chia seeds, and flaxseeds are excellent sources of healthy fats, protein, and fiber.
  • Avocados: These creamy fruits contain heart-healthy monounsaturated fats, fiber, and vitamins.

Lean Proteins

Including lean protein sources in your diet is vital for maintaining muscle mass, promoting satiety, and supporting overall health. Choose the following options:

  • Fish: Opt for fatty fish like salmon, trout, or sardines, which are rich in omega-3 fatty acids and provide additional health benefits.
  • Poultry products: Skinless chicken or turkey breast is a lean source of protein that can be prepared in various ways.
  • Plant-based protein: Tofu, tempeh, legumes, and lentils are excellent alternatives for those following a vegetarian or vegan diet.

Whole Fruits

While fruits contain natural sugars, they are also high-fiber foods rich in vitamins and minerals. Including whole fruits in moderation can provide essential nutrients without causing rapid spikes in blood sugar levels. Some examples of whole fruits to enjoy include:

  • Citrus fruits: Oranges, grapefruits, lemons, and limes are not only refreshing but also provide vitamin C and fiber.
  • Berries: Strawberries, blueberries, raspberries, and blackberries are packed with antioxidants and fiber.
  • Apples and pears: These fruits offer a satisfying crunch and are a good source of dietary fiber.

Above all, remember to stay hydrated always. Drinking plenty of water throughout the day helps optimize body functions, supports metabolism, and aids in maintaining the overall health of a diabetic patient.

What is Metformin Used for?

Metformin is a widely prescribed first-line, inexpensive medication for prediabetes and type 2 diabetes management. It helps regulate blood sugar levels and improve insulin sensitivity. About 14.4 million people in the United States received a prescription for Metformin in 2014 alone.

Metformin is typically prescribed for individuals with diabetes when dietary changes and exercise alone have proven ineffective in managing blood sugar levels.

While not officially approved, Metformin is sometimes used to address symptoms associated with polycystic ovary syndrome (PCOS), a condition affecting ovarian function.

In PCOS patients, Metformin reduces insulin and blood sugar levels, which can improve ovulation and promote regular menstrual cycles, even in the absence of diabetes.

Metformin is available in tablet form and a liquid formulation for oral consumption. Additionally, it comes in sachets of powder that can be dissolved in a beverage.

Before using metformin for PCOS or any other condition, always discuss it with your healthcare provider. Your doctor may prescribe the drug off-label based on your body condition and medical history.

When to Take Metformin and How?

To minimize the potential side effects of Metformin, taking it with or immediately after your evening meal is recommended. However, your doctor may suggest taking metformin at bedtime instead of dinner to improve diabetes control by reducing morning hyperglycemia.

Ensure you swallow the Metformin tablets whole, along with a glass of water. It is important not to chew or crush the tablets. In the case of Metformin sachets, pour the powder into a glass and add approximately 150ml of water before consuming. Remember to follow your healthcare provider's instructions regarding the specific timing and dosage of Metformin.

Metformin Dosage

Since metformin tablets are available in various strengths, your doctor will provide specific instructions on how many tablets you should take daily.

The maximum recommended daily dose of Metformin is 2,000mg. This can be achieved by taking four 500mg tablets throughout the day.

Liquid metformin is typically administered in 5ml doses of 500mg, 850mg, or 1,000mg.

Metformin sachets are available in two doses: 500mg and 1,000mg.

Sticking to your doctor's prescribed dosage and following their instructions regarding the strength and frequency of Metformin intake is essential. Stay within the maximum daily dose unless advised by your healthcare provider.

In the event that you miss a dose of metformin, it is recommended to skip the missed dose and resume your regular dosing schedule. Do not take two doses at once to compensate for the missed dose.

If you frequently forget to take your medication, some strategies can assist you in remembering. Setting an alarm or reminder, for instance, can be helpful. Your doctor or pharmacist can also provide valuable advice on alternative methods to remember your medicine schedule.

Signs of Metformin Overdosage

An overdose of metformin, which can lead to metformin-associated lactic acidosis, manifests with various symptoms, including severe nausea, vomiting, diarrhea, epigastric pain, thirst, loss of appetite, lethargy, and increased breathing rate (hyperpnea).

Clinical presentations of metformin overdose may also involve hypotension (low blood pressure), hypothermia (low body temperature), acute renal failure (sudden kidney dysfunction), pancreatitis, coma, and even cardiac arrest. It is crucial to seek immediate medical attention if you suspect metformin overdosage to ensure appropriate management and minimize potential complications.

Warnings and General Precautions

Metformin may be deemed unsafe for individuals with certain medical conditions, including:

  • Kidney problems or disorders: Pre-existing kidney issues may require adjustments to the dosage or close monitoring when using metformin.
  • Metabolic acidosis: Metformin is not recommended for individuals with metabolic acidosis, a condition characterized by an excessive accumulation of acid (hydrogen ion) in the body.

If you are taking metformin, you may be advised to discontinue the usage temporarily before undergoing surgical procedures or radiological testing. The iodine contrast used for these procedures can interact with metformin and potentially cause complications.

Metformin also has the potential to interact with many other medications, including Beta blockers, Procainamide, Triamterene, Cimetidine, and Corticosteroids, among others.

It is important to inform your healthcare provider about all your medications, supplements, and herbal products to avoid potential interactions. Your doctor can help you with the appropriate use of metformin and any necessary adjustments or precautions based on your specific medical condition(s).

Frequently Asked Questions

What is the most serious side effect of Metformin?

The most severe side effect of Metformin is a rare condition called lactic acidosis. Lactic acidosis is characterized by the buildup of lactic acid in the body, which can be life-threatening. However, it is essential to note that lactic acidosis is very rare and occurs primarily in individuals with underlying health conditions or those who misuse the medication.
Vitamin B12 deficiency is another primary concern for long-term metformin usage. This condition can make you feel exhausted, breathless, and faint. Your healthcare provider may perform periodic blood tests to monitor your vitamin B12 levels while you are taking this medication. If your vitamin B12 levels become too low, you may require vitamin B12 supplements to help replenish and maintain adequate levels.

How can you tell if Metformin is working?

While not everyone experiences symptoms of diabetes, it's crucial to understand that the effectiveness of metformin is not dependent on whether you feel any different. Even if you don't notice any immediate changes, it doesn't mean that the medication is not working.
Your doctor may conduct a couple of tests to assess the impact of metformin on your health. Blood work is commonly used to evaluate indicators such as glucose, insulin, and HbA1C levels. If your glucose, insulin, and HbA1C levels fall within the desired range, then the medicine is effectively managing your condition.

Can Metformin make you extremely tired?

While fatigue and tiredness may be among the side effects of metformin, they are relatively uncommon and usually not severe. The common cause of extreme tiredness while on metformin is vitamin B12 deficiency.

Can you take Metformin without food?

Don't take metformin without food. Taking metformin with meals is recommended to minimize the potential stomach or bowel side effects during the initial weeks of treatment. Moreover, fasting while on metformin may increase your risk of developing low blood sugar.


Metformin is a highly effective option for managing type 2 diabetes. However, it's important to note that lifestyle interventions, including adopting a healthy diet and achieving weight reduction (for overweight individuals), play a crucial role in managing insulin resistance and mitigating the potential long-term complications of diabetes. It is essential to adhere to the prescribed dosage and regularly consult with your doctor while on metformin. Combining the medication with healthy diets, lifestyle choices, and ongoing medical guidance can optimize your diabetes management and minimize the risks associated with the condition.


At Diabetic Me, we are committed to delivering information that is precise, accurate, and pertinent. Our articles are supported by verified data from research papers, prestigious organizations, academic institutions, and medical associations to guarantee the integrity and relevance of the information we provide. You can learn more about our process and team on the about us page.

  1. National Library of Medicine Metformin and the gastrointestinal tract
  2. National Library of Medicine Association of metformin use on metabolic acidosis in diabetic patients with chronic hepatitis B‐related cirrhosis and renal impairment
  3. National Library of Medicine Closing America’s Fiber Intake Gap
  4. National Library of Medicine Bedtime administration of metformin may reduce insulin requirements
  5. American Diabetes Association Non-starchy Vegetables
  6. NHS How and when to take metformin
  7. U.S. Food & Drug Sodium in Your Diet

About the Author

Inez Briand

Inez Briand is the partner of a type 1 diabetic (Ely). She has always been interested in traveling and cooking, and now that she has a partner with diabetes, her interest in cooking even more healthily has skyrocketed. She loves finding new recipes for her partner and family and sharing any food and nutrition-related articles on Diabetic & Me.

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