You're taking metformin and doing everything right—but something feels off. Maybe it's the stomach upset that won't quit, or the blood sugar readings that aren't improving as much as you'd hoped.

What you eat while taking metformin can make a real difference in how well the medication works and how you feel day to day. Here's a look at seven food categories worth limiting, what to eat instead, and how to time your meals for the best results.

Key takeaways

When taking metformin, limiting sugary drinks, refined carbs, processed foods, excessive alcohol, and foods high in saturated or trans fats can help the medication work more effectively. Alcohol poses a particular concern because it increases the risk of lactic acidosis, a rare but serious condition. Meanwhile, sugary and processed foods cause blood sugar spikes that work against what metformin is trying to do.

• Sugary drinks and sweets: Cause rapid blood sugar spikes that counteract metformin's blood sugar-stabilizing effects

• Alcohol: Increases risk of lactic acidosis, especially with heavy or binge drinking

• Refined carbs: White bread, pasta, and rice spike blood sugar quickly

• Processed foods: Often contain hidden sugars and sodium

• Saturated fats: Can worsen insulin resistance over time

• Fried foods: Combine unhealthy fats with refined carbs and may worsen stomach upset

• High-sodium foods: Can complicate blood pressure and heart health

Looking for a quick list? Start here. For deeper explanations of each food category, continue to the next section.

7 foods to limit or skip while taking metformin

Certain foods can interfere with how metformin works or worsen its side effects—here's what to watch for. None of the items below are strict prohibitions. They're categories to be mindful of, especially if you're experiencing side effects or not seeing the results you expected.

Metformin works by reducing glucose production in the liver and improving how your body responds to insulin. When you eat foods that cause rapid blood sugar spikes, you're essentially working against what the medication is designed to do. If you're looking for foods to eat while taking metformin instead, skip to the next major section.

Sugary drinks and sweets

Sodas, fruit juices, sweet teas, candy, ice cream, and desserts cause rapid blood sugar spikes that counteract metformin's purpose. Even drinks marketed as "healthy," like fruit smoothies or vitamin waters, can be high in sugar—though typically not quite as much as a can of soda.

• Sodas and energy drinks

• Sweetened coffee drinks

• Candy and chocolate

• Ice cream and frozen desserts

• Baked goods like cookies and cakes

Alcohol

Alcohol is the most critical item on this list. Alcohol is processed by the liver, and combining it with metformin can increase the risk of lactic acidosis—a rare but serious buildup of lactic acid in the blood.

Heavy or binge drinking poses the greatest concern. Occasional moderate drinking may be acceptable for some people, but it's worth discussing with a clinician first. If you do drink, having food in your stomach can help reduce potential issues, such as upset stomach and low blood sugar.

Refined carbohydrates and white starches

Refined carbs are grains that have been stripped of their fiber and nutrients during processing. Without fiber to slow digestion, refined carbs break down quickly and cause blood sugar to spike.

• White bread and bagels

• White pasta and rice

• Crackers and pretzels

• Sugary breakfast cereals

Many people find that reducing refined carbs helps them feel better on metformin. You don't have to go fully low-carb, but swapping white starches for whole grain alternatives can make a noticeable difference in how you feel.

Processed and ultra-processed foods

Ultra-processed foods are items with long ingredient lists, added sugars, and artificial additives. They often contain hidden sugars and sodium that can undermine your health goals without you realizing it.

• Packaged snacks and chips

• Frozen meals and dinners

• Hot dogs and processed meats

• Sugary condiments like ketchup and BBQ sauce

Reading nutrition labels helps here. Ingredients are listed in order of quantity, so if sugar or sodium appears near the top, that's a red flag.

Foods high in saturated fat

High-fat diets can worsen insulin resistance, which is often why metformin is prescribed in the first place. Diets high in processed meats and industrial fats can increase systemic inflammation, which worsens the metabolic environment metformin is trying to fix.

• Fatty cuts of red meat

• Full-fat cheese and cream

• Butter and lard

• Processed meats like bacon and sausage

Not all fats are problematic, though. Healthy fats from sources like olive oil, avocados, and nuts can actually support metabolic health. More on that in the next section.

Fried foods

Fried foods combine unhealthy fats with refined carbs from breading, creating a double challenge for blood sugar management. They can also worsen gastrointestinal side effects like nausea or urgent diarrhea, especially when you're first starting metformin.

French fries, fried chicken, doughnuts, and fried appetizers all fall into this category. High-fat meals can trigger the 'gastrocolic reflex', leading to sudden urgency or diarrhea. If you're experiencing stomach upset on metformin, cutting back on fried foods is often one of the first adjustments that helps.

High-sodium foods

Many people taking metformin also manage blood pressure or heart health concerns. High sodium can complicate blood pressure management and contribute to water retention and bloating.

• Fast food

• Canned soups and vegetables

• Salty snacks like chips and pretzels

• Deli meats

Best foods to eat while taking metformin

The right diet with metformin isn't just about what to avoid—it's about what to add. Focusing on whole, nutrient-dense foods can enhance metformin's effectiveness and support overall metabolic health.

Non-starchy vegetables

Non-starchy vegetables are low in carbs and high in fiber, helping stabilize blood sugar without causing spikes. Leafy greens, broccoli, cauliflower, peppers, zucchini, and asparagus are all excellent choices. They also tend to be gentle on the stomach.

Lean proteins

Protein helps with satiety and doesn't spike blood sugar. Good options include chicken breast, fish, turkey, eggs, tofu, and legumes. Starting meals with protein can help you feel fuller longer.

Whole grains and high-fiber carbs

Unlike refined carbs, whole grains contain fiber that slows digestion and blood sugar response, while high-glycemic foods increase disease risk. Quinoa, brown rice, oats, and whole wheat bread are better choices than their white counterparts. Even if you're not following a strict low-carb approach, choosing whole grains over refined grains can make a meaningful difference.

Healthy fats

Olive oil, avocados, nuts, seeds, and fatty fish like salmon support heart health and don't worsen insulin resistance. Healthy fats can actually help you feel satisfied after meals, which may reduce the urge to snack on less nutritious options.

Low-glycemic fruits

The glycemic index measures how quickly foods raise blood sugar. Some fruits are better choices than others when managing blood sugar. Berries, apples, pears, and citrus fruits have a lower glycemic index, meaning they raise blood sugar more gradually than tropical fruits or grapes.

Water and unsweetened beverages

Replacing sugary drinks with water, unsweetened tea, or black coffee is one of the simplest swaps you can make. Staying hydrated also supports overall metabolic function and can help reduce some of metformin's gastrointestinal side effects.

How metformin and food interact in your body

Metformin works by reducing glucose production in the liver and improving insulin sensitivity. Certain foods either support or undermine how the medication works.

• Foods that support metformin: Complex carbs, fiber, and lean proteins help stabilize blood sugar

• Foods that work against metformin: Simple sugars, refined carbs, and alcohol cause blood sugar spikes or interfere with liver processing

When you eat foods that cause rapid blood sugar spikes, metformin has to work harder. When you choose foods that stabilize blood sugar naturally, you're working with the medication rather than against it.

When to take metformin with food

Timing matters—taking metformin with food can reduce common side effects. Most clinicians recommend taking it with a meal, especially dinner or your largest meal of the day, to minimize gastrointestinal upset.

Individual guidance from a health care provider takes precedence over general recommendations. If you're experiencing symptoms at a particular time, your clinician may adjust when you take your dose.

What to do if you eat something you limited

One meal won't derail your progress—here's how to get back on track. Occasional indulgences happen, and they aren't cause for panic or self-criticism.

• Don't skip your next metformin dose

• Return to your usual eating pattern at your next meal

• Stay hydrated

• Monitor for any unusual symptoms

• Avoid "making up for it" by skipping meals

The goal is consistency over time, not perfection at every meal.

Metformin side effects related to food

Knowing which side effects are food-related can help you manage them more effectively. Gastrointestinal side effects occur in approximately 20% of users, especially when starting metformin, and often improve over time.

Common side effects

• Nausea: Often triggered by greasy, spicy, or sugary foods

• Diarrhea: May worsen with high-fat foods initially

• Stomach upset: Can be minimized by taking metformin with food

• Gas and bloating: Common in early weeks, usually improves

Most of the side effects above lessen as your body adjusts to the medication. Taking metformin with food and avoiding trigger foods can help during the adjustment period.

Serious side effects to watch for

Lactic acidosis is rare but serious, and it can increase in individuals with kidney impairment or liver disease. Symptoms include unusual muscle pain, weakness, difficulty breathing, and extreme fatigue. If you experience any of the symptoms above, seek medical attention immediately.

Long-term Metformin use can also affect vitamin B12 levels in some people as it reduces B12 absorption in the ileum, with 22.2% experiencing deficiency, so it's often recommended that metformin patients take a daily B-complex vitamin or have their B12 levels checked annually to prevent neuropathy. If you notice unusual fatigue or tingling in your hands and feet, it's worth discussing with your clinician.

Other metformin interactions to know about

Beyond food, other substances can interact with metformin—here's what to discuss with your clinician. If you're primarily concerned about metformin foods to avoid, you can skip this section and jump to practical tips below.

Medications that may interact with metformin

Always share your full medication list with your provider. Some categories that may interact with metformin include certain diabetes medications, some blood pressure medications, diuretics, and steroids. The list above isn't exhaustive, so clinician guidance is important.

Supplements and vitamins

Some supplements may affect blood sugar or metformin absorption. Supplements are not replacements for medical care and are worth discussing with a health care provider before starting. Even "natural" supplements carry potential risks and interactions.

Medical imaging and contrast dye

Metformin may need to be temporarily stopped before procedures involving contrast dye. If you're scheduled for any imaging procedures, inform medical staff about your metformin use beforehand.

Tips for eating well on metformin

Small, sustainable changes to your diet with metformin can make a meaningful difference. You don't have to overhaul everything at once.

• Plan meals ahead: Reduces reliance on processed convenience foods

• Read nutrition labels: Watch for hidden sugars and sodium

• **Practice **meal sequencing: Consider eating vegetables and protein before carbs

• Stay hydrated: Water supports overall metabolic function and can help reduce some of metformin's gastrointestinal side effects

• Keep healthy snacks accessible: Nuts, vegetables, cheese

• Focus on progress, not perfection: Consistency matters more than any single meal

Personalized guidance from a weight care specialist can help identify what works best for your body. Everyone responds differently, and what works for one person may not work for another.

When to talk to your health care provider about metformin and diet

Your clinician is your best resource for personalized guidance on foods to avoid while taking metformin. Some situations that warrant a conversation include persistent gastrointestinal side effects despite dietary adjustments, questions about alcohol consumption, concerns about nutrient deficiencies, significant changes to your diet, planning for medical procedures, and symptoms that feel unusual or concerning.

Asking questions is always appropriate—no concern is too small.

Finding what works for your body

Everyone's body responds differently to metformin—personalized support can help you find your path. Knowing which foods to avoid is just one piece of comprehensive weight care.

Biology plays a real role in how your body responds to food and medication. Working with experts who understand metabolic health can help identify the right approach for you specifically.

Found is among the largest medically-supported telehealth weight care platforms in the country, having served more than 250,000 members to date. To discover your MetabolicPrint™ and start your journey with Found, take our quiz: https://clinic.joinfound.com/health-assessment-survey/welcome.

*Metformin is only FDA-approved to treat type 2 diabetes. Prescriptions are provided only if clinically appropriate after evaluation by a licensed provider. Visit our website for risk information.

Individual results may vary.

FAQs about metformin and food

Can metformin cause headaches?

Headaches aren't a common side effect of metformin itself, but blood sugar fluctuations or dehydration while taking the medication may contribute to headaches in some people.

Does metformin work better with a low-carb diet?

Reducing refined carbohydrates can support metformin's blood sugar-stabilizing effects, though the best dietary approach varies by individual and is worth discussing with a health care provider.

Can metformin be taken on an empty stomach?

While metformin can technically be taken without food, taking it with meals typically reduces gastrointestinal side effects like nausea and stomach upset.

Can metformin cause acid reflux?

Some people experience acid reflux or heartburn while taking metformin, particularly if taken without food. Taking the medication with a meal may help reduce this symptom.

Does grapefruit interact with metformin?

Unlike some medications, metformin doesn't have a known significant interaction with grapefruit, though it's always wise to discuss dietary questions with a health care provider.