Metformin is a common medication prescribed to help manage type 2 diabetes. It works by reducing glucose production in the liver and improving the body’s sensitivity to insulin. While metformin is generally well tolerated, it can sometimes cause gastrointestinal side effects like nausea, vomiting, diarrhea, and upset stomach.
The way certain foods interact with metformin can worsen these side effects. Being mindful of your diet and making adjustments to the types and amounts of foods you eat can help reduce metformin side effects. Here is a closer look at what foods to avoid or limit when taking metformin.
Foods with Simple Sugars
Foods that are high in simple sugars can cause your blood sugar to spike soon after eating. This rapid rise in blood glucose can interact with how metformin works and lead to unwanted side effects. Foods to be mindful of include:
Candy
Candy is packed with simple sugars like sucrose, glucose, fructose, and maltose. Eating a lot of candy could cause stomach upset, diarrhea, or other digestive discomfort from metformin. It’s best to avoid candy or only eat it occasionally in small amounts.
Sugary Cereals
Many breakfast cereals, especially those marketed to children, are loaded with sugar. The same goes for instant oatmeal flavored with sugar. Choosing unsweetened whole grain cereals or plain oats is a healthier option when taking metformin.
Sugary Baked Goods
Cookies, cakes, muffins, doughnuts and other baked goods are high in added sugars. They can interact with metformin, so these treats are better left alone or just eaten on special occasions when you’re taking this medication.
Fruit Juice
Even though fruit juice provides some vitamins, it’s also very high in simple sugars. Drinking a lot of juice like orange juice, apple juice or cranberry juice can cause blood sugar spikes and metformin side effects.
Sports and Energy Drinks
Sports drinks like Gatorade and Powerade as well as energy drinks like Red Bull and Rockstar contain sugars and carbohydrates. They are best avoided when taking metformin, especially right before or after exercise.
Sweetened Beverages
Sodas, lemonade, sweet tea, and other sugary drinks can interact with metformin and cause digestive as well as blood sugar issues. Choose water or unsweetened teas and coffees instead.
Refined Carbohydrates
Refined grains like white bread, pasta, rice, and baked goods act similarly to sugar in the body. They are digested and absorbed quickly, causing a rapid rise in blood sugar. Limiting refined carbs may help reduce metformin side effects.
White Bread
White bread made from refined wheat flour can spike blood sugar. Sourdough, whole grain, or seeded bread may be less likely to interact with metformin. Or try healthy lettuce wraps instead of bread.
White Pasta
Pasta made from refined white flour can cause blood sugar spikes. Opt for whole wheat or vegetable-based pastas instead. Zucchini noodles are a great alternative.
White Rice
Like white bread and pasta, white rice is a refined carb that can raise blood sugar quickly. Brown rice, wild rice, or cauliflower rice are smarter choices.
Baked Goods
Cookies, cakes, croissants, muffins, and donuts made with white flour cause rapid blood sugar rises. Limit baked goods or pick whole grain versions made with less refined ingredients.
Crackers
Refined flour crackers lack fiber, so they aren’t the best choice when taking metformin. Seek out more nutritious crackers made with whole grains or seed flours instead.
Fried Food
Fried foods tend to be hard to digest and high in fat, both of which can irritate the stomach. French fries, fried chicken, mozzarella sticks, and other deep-fried foods are best avoided when first starting metformin.
French Fries
French fries are cooked in hot oil, which can be difficult to digest. Mashed or baked potatoes are gentler alternatives.
Fried Chicken
The batter and frying process make fried chicken hard on the stomach. Grilled or baked chicken is a better option.
Fried Vegetables
Even vegetable tempura can irritate the stomach. Steamed or roasted vegetables are easier to digest.
Fried Fish
Fish and chips or other fried seafood can cause GI upset with metformin. Grill, bake, or broil fish instead of frying.
Doughnuts
Fried sugary doughnuts are a double whammy that can really irritate the stomach. Avoid doughnuts or pick cake style ones when taking metformin.
Fatty Meats
High-fat meats take longer to digest. This can allow metformin to sit in the stomach longer, increasing the chances of side effects like nausea. Go easy on fatty meats like:
Bacon
The high fat content of bacon can exacerbate metformin side effects. Turkey bacon may be better tolerated.
Sausage
Sausage is very high in fat, especially saturated fat. Swap in turkey sausage or lean chicken sausage instead.
Hot Dogs
Like sausage and bacon, hot dogs tend to be very fatty. Lower fat options include chicken or turkey dogs.
Salami
Salami and other deli meats can be hard to digest due to their high fat content. Leaner lunch meat options include turkey and chicken breast.
Ribeye Steak
Ribeyes and other fattier cuts of red meat can bother the stomach. Try leaner cuts like sirloin or filet mignon.
Foods that Cause Gas
Some healthy foods are notorious for causing gas, which can be aggravated by metformin. Slowly introducing gas-producing foods may help. But you may need to limit:
Beans
The natural sugars in beans called oligosaccharides can cause gas. Try an enzyme product like Beano to help break them down.
Cabbage
Cabbage, Brussels sprouts and other cruciferous veggies are common culprits. Cook them well before eating to reduce gas.
Onions
Onions contain fructans that can cause bloating. Cooking onions may help reduce this effect.
Apples
Apples have the sugar fructose that can lead to gas when not digested properly. Try peeled and cooked apples.
Dairy
Lactose in dairy foods causes gas in people with lactose intolerance. Try lactose-free milk or lactase enzymes.
Fatty and Fried Foods
Very fatty foods or deep-fried foods can be difficult to digest and sit heavy in the stomach. This can further irritate the GI tract when taking metformin. It’s best to limit:
Fatty Red Meat
Ribeye steaks, prime rib, sausage, and bacon are very high in fat. Leaner cuts of meat cause less GI upset.
Fried Chicken
The coating and frying process make fried chicken hard to digest. Oven-baked or grilled chicken is gentler.
Pizza
Pizza is high in fat, carbs, and commonly includes dairy and processed meats that can cause trouble. Try lighter veggie or thin crust.
Mac and Cheese
Ooey-gooey mac and cheese is high fat and can really bother the stomach. A smaller portion may be better tolerated.
Fried Fish
The batter and frying make fish and chips hard to stomach. Broiled or grilled fish is a healthier choice.
Other Tips for Managing Your Diet with Metformin
Here are some other helpful diet tips to keep in mind when taking metformin:
- Eat small, frequent meals – Don’t overload your stomach.
- Increase fiber – It slows carb absorption.
- Stay hydrated – Drink water and avoid soda.
- Read labels – Check added sugars and carbs.
- Ask your pharmacist – About any food/drug interactions.
- Take metformin with food – This helps reduce side effects.
- Don’t drink alcohol – It can worsen side effects.
Foods to Enjoy with Metformin
Focus on eating more of these foods that are generally well-tolerated with metformin:
Non-starchy Vegetables
Leafy greens, broccoli, peppers, carrots, and most other non-starchy vegetables are low in carbs and calories. Enjoy them raw or cooked.
Lean Protein
Chicken, turkey, fish, eggs, tofu, beans, lentils, and nuts are healthy protein sources. Choose leaner cuts of meat.
High-fiber Fruits
Berries, grapefruit, papaya, peaches, apples, and pears are lower glycemic fruits. Be mindful of portion sizes.
Whole Grains
Try oatmeal, quinoa, brown rice, whole grain pasta, and 100% whole wheat bread in moderation.
Healthy Fats
Avocados, olive oil, nuts, seeds, and fatty fish like salmon provide filling healthy fats and fiber.
Sample Meal Plan
Here is a sample one-day meal plan with foods that tend to be well-tolerated when taking metformin:
Breakfast
– 1/2 grapefruit
– Scrambled eggs with spinach and tomatoes
– Avocado toast on whole grain bread
Lunch
– Salmon salad with lettuce, cucumbers, carrots
– Apple slices with peanut butter
– Whole grain crackers
Dinner
– Herb-roasted chicken breast
– Roasted Brussels sprouts and broccoli
– Brown rice
– Greek yogurt with blueberries
Conclusion
When taking metformin, be mindful of foods high in sugar, refined carbs, and unhealthy fats, which can interact with the medication and worsen side effects. Focus on lean proteins, non-starchy veggies, high-fiber fruits, and whole grains. Drink plenty of water and eat smaller, frequent meals. With some adjustments, you can find a diet that works well with metformin.
