5 Things That Don’t Mix Well with Your Diabetes Medications

When you have diabetes, the focus is often on eating a healthy diet to better manage the disease and timing your meals with your medications. But understanding what specific foods and drinks interact with your medications is also key. “Diabetes medications are designed to work in a very specific way to help control your blood sugar,” says Elaina Rosario, Pharm.D., CPh, BCACP, CDCES. “When you eat certain foods, they can change how your medication is absorbed, how it works in your body, or how quickly it is used up. This can sometimes make the medication less effective, or in some cases, too strong.” 

Rebecca Emch, Pharm.D., agrees, “From a pharmaceutical perspective, food interactions with diabetes medications occur through several mechanisms.” The effects vary depending on the type of medication you’re taking. “For medications like metformin, certain foods can affect absorption rates and bioavailability,” says Emch. However, this type of interaction isn’t as common since many times the foods in the diet don’t directly affect absorption of the medications. Instead, Emch says that it’s more common that foods eaten work against their intended purpose. “When you take a diabetes medication to lower blood sugar, and then consume foods that cause rapid glucose spikes, you’re essentially creating a tug-of-war in your system,” she says. Other foods like those high in fat may also have an impact. 

Because of these effects, Cari Riker, RDN, LDN, CDCES emphasizes the importance of following a diet that helps you best manage your blood sugar while also preventing medication interactions. “Selecting foods that reduce these impacts can help improve tolerance and effectiveness,” says Riker. We’re sharing which types of foods may interact with your diabetes medications and tips on how to stay safe.

1. High Fat Foods

Some dietary fats like unsaturated fats are beneficial for health, but saturated fats in excess are associated with an increased risk for type 2 diabetes. Additionally, meals that are high in fat may affect the bioavailability of certain medications. “High-fat foods slow digestion which delays how quickly some medications are absorbed and when they take effect,” says Daria Zajac, RD, LDN. “Examples of high fat foods include whole-fat dairy products, processed meats, fried foods and baked goods like cookies and cake.” Not only can they slow down how fast a medication works, according to Rosario, they can also trigger the gastrointestinal side effects of glucagon-like peptide-1 receptor agonists (GLP-1 RA) such as nausea, vomiting and diarrhea.

2. Foods High in Added Sugar

 “Limiting high-sugar foods can help prevent rapid spikes and crashes in blood sugar,” says Riker. This is because foods with added sugar may make it more difficult for your diabetes medication to work as intended. Emch points to high sugar foods like candy, sodas and desserts as well as fruit juices as some of the biggest culprits when it comes to foods that work against your diabetes medication. 

“These don’t stop medications like metformin from working, but they make it significantly harder to maintain stable blood sugar levels,” says Emch. “It’s like trying to bail water out of a boat while someone else is pouring more water in.” This doesn’t mean avoiding all foods with carbohydrates and sugar. Instead, focus on whole food sources of carbohydrates that are also natural sources of fiber like beans and legumes, whole grains, and whole fruits and vegetables whenever possible. “The quality and quantity of carbohydrates matter,” says Riker.

3. Highly Processed and Refined Carbohydrates

Foods that are primarily carbohydrates and are also highly processed like white bread, high sugar cereals, chips, pretzels, crackers and baked goods like croissants, cookies and pies can often cause a spike in your blood sugar. “If you take a fast-acting insulin or a medication that works with meals, this sudden spike can make it difficult for the medication to keep up, or it could lead to a sudden drop later if the medication works too aggressively to bring it down,” says Rosario.

“While your diabetes medication is designed to manage blood sugar, it’s much easier for it to work effectively when your blood sugar levels are kept more stable.” If you choose to include highly processed or refined carbohydrates in your diet, it can help to pair them with protein or fat as part of a balanced meal. This combination can help to slow digestion which may prevent blood sugar spikes.

However, most of the diet should not be made up of highly processed carbohydrate sources. “The American Diabetes Association (ADA) specifically recommends that people with diabetes preferentially eat minimally processed sources of carbohydrate that are high in fiber,” says Joshua J. Neumiller, Pharm.D., CDCES, FADCES, FASCP, president of health care & education at the American Diabetes Association.

4. Caffeine

Medications that are in the class of SGLT2 inhibitors like Jardiance, Steglatro, and Farxiga work by allowing excess sugar to be removed via urine. The diuretic effect of these medications may be compounded by the diuretic effect of excess caffeine. This doesn’t mean a cup of coffee or two will be a cause for concern, but those taking these medications should consider sticking to the recommended limit of 400mg caffeine per day (or approximately three to four cups of coffee).

5. Alcohol

“Alcohol should be limited when taking diabetes medications,” says Zajac. Drinking alcohol on an empty stomach or when skipping meals may worsen the effect it has when taking diabetes medications. “Alcohol increases the risk of low blood sugar, especially for those taking insulin or sulfonylureas, since it interferes with the liver’s ability to release glucose into the bloodstream,” says Riker. 

Riker also says that alcohol can worsen side effects like nausea and digestive upset when taking medications like metformin. “For those on SGLT2 inhibitors (i.e. Jardiance, Farxiga), alcohol’s dehydrating effects can increase the chances of dehydration, low blood pressure and rare but serious complications like diabetic ketoacidosis (DKA).”

Following recommendations to limit alcohol is essential when undergoing diabetes treatment. “The ADA recommends that people with diabetes consume alcohol in moderation by limiting intake to ≤2 drinks per day for men and ≤1 drink per day for women,” says Neumiller. “It is important that people with diabetes understand that hypoglycemia can be delayed after drinking alcohol and that blood glucose levels should be monitored carefully to prevent severe low blood glucose levels.” For these reasons, it’s recommended that any alcohol intake is discussed with your doctor pharmacist.

How to Stay Safe

With so many diabetes medications available today, it’s difficult to provide one-size-fits-all recommendations when it comes to your diet and food choices. “Your pharmacist is a great resource for understanding how best to take your diabetes medications in relation to meals and if any specific types of foods should be avoided with your prescribed medications,” says Neumiller. These tips can get you started with making changes that work best for you.

Consider Meal Timing: Be sure to time meals and snacks appropriately depending on what’s recommended for your medication as different medications can have different effects. “Some medications need to be taken with the first bite of a meal, while others are taken 30 minutes before, and some are taken with your evening meal,” says Rosario. “Missing the right timing can affect how well the medication works.”

Stay Hydrated: “Hydration is essential, especially for those on SGLT2 inhibitors like Jardiance or Farxiga, which can increase fluid loss and raise the risk of dehydration or electrolyte imbalance,” says Riker. Drink primarily water and other unsweetened beverages to promote optimal hydration.

Consider Portion Sizes: Some medications may require paying special attention to portion sizes than others. “For those on GLP-1 receptor agonists such as Ozempic, Trulicity, or Victoza, large or high-sugar meals may worsen nausea or lead to dumping syndrome,” says Riker.

Monitor Your Numbers: “A tool that can be used to monitor how foods affect your blood sugar is a continuous glucose monitor,” says Rosario. “They are available with a prescription and over the counter and provide a great insight on how food and your diabetes medications affect your blood sugar levels.” When you monitor your blood sugar, you can identify trends based on the foods you eat and the timing of your medications. “Pay attention to how you feel after eating certain foods. If you notice a pattern of feeling unwell or having unusual blood sugar readings after a particular meal, it’s a good idea to talk to your doctor or a registered dietitian,” says Rosario.

Consider All Medications and Supplements: “Other medications and supplements can affect blood sugar or interact with diabetes drugs, so it’s important to consider your full medication list when planning meals,” says Zajac. Pharmacists are an important resource to patients when identifying potential food-drug interactions.

Managing diabetes requires paying close attention to when and what you eat as well as the timing of your medication. You should adjust your diet to allow room for the foods you enjoy while also limiting those that may cause significant interactions with your diabetes medications like those high in added sugars, saturated fat, highly processed carbohydrates, and caffeine.

Monitoring your blood sugar is the best way to ensure your current plan is working for you. But seeking the care of a registered dietitian or other healthcare provider can be helpful to provide guidance and support, especially if you’re newly diagnosed. “Bottom line, it is important to work with your healthcare professional to be educated on possible side effects of your medication so you can better manage your blood sugar levels and prevent side effects,” says Riker.