Metformin is one of the first drugs of choice for treating type 2 diabetes. It’s also sometimes used to treat conditions like gestational diabetes or PCOS. But this little-known fact—what you eat can make a difference in how well metformin works and how you feel while taking it. Here are the foods that are standing in your way, and the foods that can work with them.

1. Simple and Refined Carbohydrates
These include things like white bread, white rice, plain pasta, muffins, and sugary breakfast cereals. These are metabolized super rapidly and can make your blood sugar spike, making it more difficult for the metformin to work. Dietitian Erin Palinski-Wade recommends replacing these with whole grains such as oatmeal, brown rice, and whole wheat bread in order to maintain stable blood sugar levels.
2. High-Sugar Foods and Drinks
Sugar is lurking in many foods—from soda and fruit juice to cookies, cakes, and even yogurts and salad dressings. Consuming a great deal of added sugar has been shown to promote insulin resistance, decreasing the effectiveness of metformin. Palinski-Wade suggests keeping added sugars low—six teaspoons a day for women, nine for men. Natural sugars from fruits and vegetables are usually fine in moderation, but pay attention to labels for sneaky sugars in packaged foods and beverages.
3. Saturated and Trans Fats
Saturated-fat-loaded foods such as red meat, butter, full-fat milk products, fried foods, and most baked products cause inflammation and worsen insulin resistance. Trans fats are worse still and are also frequently encountered in margarine, packaged snacks, and pastries from bakeries. The official advice is to limit saturated fat to less than 10 percent of daily calories and try to eliminate trans fats as much as possible. Healthy fats and lean proteins are a healthier approach to nourishing your heart and your blood sugar levels.
4. High-Sodium Foods
Many processed foods—such as deli meat, canned soups, frozen dinners, and restaurant takeout—are loaded with sodium. If you have diabetes, you’re already at a greater risk for cardiovascular issues, and excess sodium can increase your blood pressure. The rule of thumb is less than 2,300 milligrams a day, or 1,500 if you already have high blood pressure or kidney issues. Home cooking with fresh ingredients can really be helpful for keeping your sodium under control.
5. Alcohol
Both metformin and alcohol are metabolized in the liver, so immoderate drinking will place additional stress on that organ. It can also increase your chances of getting lactic acidosis, a rare but dangerous condition. Dr. Danielle Kelvas recommends limiting drinking to one or two beverages a day at most and refraining from overindulging. Alcohol will also interfere with your blood sugar levels, so moderation is key here.
6. Too Much Fiber All at Once
Fiber is great for managing diabetes, but overloading on it in one meal can interfere with how your body absorbs metformin. Dr. Yoshua Quinones recommends spreading your fiber intake out across the day and drinking plenty of water. Foods like leafy greens, beans, apples, and whole grains are all excellent—just try not to go overboard all at once, especially right when you’re taking your meds.
7. Ultra-Processed Foods
Not everything that comes in a package is bad for you, but ultra-processed foods—such as candy bars, fast foods, packaged snacks, and ready-to-eat meals—are likely high in sugar, salt, and unhealthy fats. They can subvert the effects of metformin and complicate controlling your blood sugar and weight. The best strategy is to read labels and select items that are as close to their natural state as possible.
What to Eat Instead
The good news? There are plenty of foods that work with metformin to help your health. Lean protein sources such as chicken, turkey, fish, eggs, and tofu make you feel full and keep your blood sugar levels stable. Slow-digesting complex carbs and high-fiber foods, such as oats, brown rice, quinoa, lentils, and beans, slow down the rise. Good fats from foods such as avocados, olive oil, nuts, and seeds are good for your heart. And don’t miss non-starchy vegetables (such as spinach, broccoli, and zucchini) and low-sugar fruit (such as apples and berries) for a colorful, balanced plate.
Tips for Minimizing Side Effects and Maximizing Metformin
Taking metformin with meals can ease common side effects like nausea or stomach upset. Starting with a low dose and increasing slowly may also help your body adjust. If stomach issues persist, ask your doctor if the extended-release version is a better fit—it’s often gentler on the digestive system.
Also, avoid skipping meals. Skipping can cause blood sugar fluctuations and make it more difficult to control your levels. Regular, balanced meals are your best option. If you don’t know how to construct a meal plan that is compatible with your lifestyle, a registered dietitian can help you customize your strategy.
Metformin is a strong medicine, but what you eat can make a huge difference in your energy level and how well it helps your body.