While medications like metformin can help you gain control over your blood sugar, it doesn't give you the freedom to eat whatever you want. While there's no metformin diet, you should be following the diet recommended to you by your doctor or dietitian to manage your blood sugar.
What Is Metformin?
Metformin is a medication prescribed as a treatment for Type 2 diabetes, prediabetes and insulin resistance. Of the more than 30 million people with diabetes, 90 to 95 percent of them have Type 2 diabetes, reports the Centers for Disease Control and Prevention.
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This type of diabetes most often affects adults over age 45 and occurs when your cells no longer respond to insulin, which is a hormone that helps get glucose from your blood into your cells to supply energy. Over time, the excess glucose in your blood damages your blood vessels and organs, placing you at risk for other health issues, such as heart disease, kidney disease and neuropathy.
Metformin falls into a class of drugs referred to as biguanides, which are medications that prevent your liver from producing glucose. According to MedlinePlus, metformin also decreases the amount of glucose your body absorbs from the food you eat and improves your body's response to insulin.
While it may seem that metformin can help you gain control over your blood sugar in multiple ways, it's not a miracle drug or cure for your diabetes. In order to get the best outcomes from the medication, it should be used in addition to the healthy diet and exercise program designed by your doctor or dietitian.
Is There a Metformin Diet?
As mentioned previously, there's not really a specific diet for people taking metformin. But when it comes to managing diabetes, your diet plays as much of a role as your medication, if not more so.
During digestion and metabolism, certain types of food, namely carbohydrate-containing foods, get broken down into glucose, which your body then uses to supply your cells with energy. If you have more glucose than your cells need, your body stores it in your liver or muscles for later use or turns it into fat.
Carbohydrate-containing foods include:
- Breads, starches, grains and cereals
- Fruit and fruit juice
- Milk and yogurt
- Starchy vegetables such as potatoes, peas and corn
- Beans, peas and lentils
You don't need to omit carbohydrates from your diet if you have diabetes, but you do need to control the amount you eat at each meal. There are several different methods used to help control carbohydrate intake and blood sugar level. The best one for you depends on many factors and should be determined by you, your doctor and your dietitian.
Ways to Control Your Carbs
A breakdown of some of the methods you can use to control your carb intake to manage your diabetes includes:
Carbohydrate Counting: Also referred to as carb counting, it's a type of meal plan where you're given a set amount of carbohydrates to eat at each meal and snack, either in grams or portions. For example, you may be allowed 45 grams (three carbohydrate servings) at each meal and 15 grams (one carbohydrate serving) at your snack. This style of eating gives you more flexibility with choices, while still helping you control your blood sugar.
With carbohydrate counting, you round out your meals with carb-free or low-carb foods, such as lean proteins, healthy fats and nonstarchy vegetables.
Low-Glycemic Diet: The low-glycemic diet takes into consideration how certain types of carbohydrates affect blood sugar. Foods like white bread, which is a high-glycemic food, may cause a rapid rise in blood sugar, while whole-grain bread would only cause a small, but steady rise in blood sugar.
Keeping blood sugar levels even by including more low-glycemic foods may help prevent quick increases in blood sugar and excessive release of insulin, which may mean better control over your diabetes.
Choose Your Foods: If you need a little more structure for meal planning, then you may benefit from the "choose your foods" method. This method provides specifics on the amount of carbohydrates, protein and fat you can eat each day and at each meal. This not only helps with blood sugar control, but may be beneficial for weight loss by helping you control portions and calories.
Create Your Plate: For many, being diagnosed with diabetes can cause a range of feelings, which may make following a complicated diet that requires counting, label reading and research difficult. To keep things simple, the American Diabetes Association has created a diet plan they refer to as Create Your Plate.
With this method, you divide your plate into sections, filling half your plate with nonstarchy vegetables, one-quarter with healthy carbohydrates and one-quarter with a lean protein. Then, you may round out your meal with a serving of dairy and fruit.
Any of these methods include good food to eat while taking metformin.
Potential Side Effects of Metformin
Like many prescription medications, metformin may cause side effects you find uncomfortable. According to a December 2016 review published in Diabetes, Obesity & Metabolism, the most common complaints affect the digestive system and include diarrhea, nausea, vomiting, abdominal pain and gas, with nausea and diarrhea topping the list.
According to the authors of the review in Diabetes, Obesity & Metabolism, it's not fully understood why metformin causes gastrointestinal distress. Given that the medication affects your body's ability to absorb glucose, it's been theorized that you may experience metformin diarrhea after carbs are consumed. However, according to Mayo Clinic, the gastrointestinal side effects are most often experienced when people take their medication without food.
If you're experiencing gastrointestinal issues, you should take your medication with food as directed. The authors of the review also suggested you may find it easier to tolerate a lower dose or the extended-release version of the medication.
Metformin, PCOS and Weight Loss
Polycystic ovary syndrome (PCOS) is a hormonal condition that affects women during their childbearing years. PCOS affects ovulation and may cause an increase in the production of androgens, which are male hormones (also found in women) responsible for facial hair growth and male-pattern baldness.
In addition to putting you at risk for developing infertility, depression and Type 2 diabetes, PCOS also increases your risk of obesity. Lifestyle changes that include a healthy diet and exercise program to lose weight are often recommended as a method of treatment for women with PCOS.
Metformin is sometimes prescribed to women with PCOS who are struggling with infertility to help improve ovulation and their chances of conception. It was also once theorized that metformin may have an added benefit of helping women with PCOS lose weight. However, according to a June 2010 review published in Endocrinology and Metabolism, there's no evidence to support the theory that metformin can help you lose weight if you have PCOS.
Read more: How To Lose Weight With PCOS
Grapefruit and Metformin
Grapefruit is a considered a healthy fruit. It's low in calories and rich in fiber and vitamin C. However, if you're taking any prescription medication, you may want to talk to your doctor or pharmacist to see if it's safe to take your medication with grapefruit or grapefruit juice.
According to the Food and Drug Administration, grapefruit and its juice affects drug metabolism by blocking an enzyme in your liver — CYP3A4 — that helps break down various medications. As a result, more of the medication enters your bloodstream than is needed, which can lead to health consequences.
Read more: The Effects of Eating Too Much Grapefruit
While there are many medications that interact with grapefruit, metformin isn't one of them. If you have concerns, talk to your doctor or pharmacist.
- MedlinePlus: "Metformin"
- Centers for Disease Control and Prevention: "Type 2 Diabetes"
- Mayo Clinic: "Diabetes Diet: Create Your Healthy Eating Plan"
- Harvard T.H.Chan School of Public Health: "Carbohydrates and Blood Sugar"
- American Diabetes Association: "Create Your Plate"
- Diabetes, Obesity & Metabolism: "Understanding and Overcoming Metformin Gastrointestinal Intolerance"
- Mayo Clinic: "Metformin Revisited"
- Mayo Clinic: "Polycystic Ovary Syndrome"
- Endocrinology and Metabolism: "Role of Metformin in the Management of Polycystic Ovary Syndrome"
- Food and Drug Administration: "Grapefruit Juice and Some Drugs"
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