A low-carbohydrate diet is generally recommended for people who have Type 2 diabetes or who are at risk of developing the disease. Metformin is a common medication used to treat type 2 diabetes. This article explores the use of a low-carb diet in conjunction with metformin, including potential benefits, risks, and key considerations.
Understanding Low-Carb Diets
There is no universally agreed upon recommendation for how many carbs to eat on a low-carb diet. People who follow a low-carb diet have a lot of freedom to choose how many carbohydrates they’ll eat in a day. Most Americans get about 45 percent of their total daily calories from carbs. So, anything less than 26 percent of your daily calories from carbs can be considered low-carb. For someone on a 2,000-calorie diet, that would mean eating fewer than 130 grams (g) of carbs per day. Very low carb diets, including the keto diet, run as little as 20 to 50 total g of carbs per day.
The ketogenic diet is an ultra-low-carb, very high-fat diet that involves a drastic reduction in carbohydrate intake. "The lower in carbs you go, the more you're wiping out entire food groups that are considered very nutrient dense and healthy," he said, noting that to achieve an extreme restriction of carbohydrates, the ketogenic diet prohibits legumes, fruits and whole grains.
Benefits of Low-Carb Diets with Metformin
Improved Blood Glucose Control
A study conducted from June 2019 to December 2020 recruited 40 adults with Type 2 diabetes or prediabetes to try both the ketogenic diet and the Mediterranean diet. Half the participants started with the ketogenic diet, and the other half with the Mediterranean diet. After 12 weeks, the groups switched and tried the other diet for 12 weeks. The researchers found that both diets improved blood glucose control, as indicated by similar drops in HbA1c levels (9% on keto and 7% on Mediterranean).
Weight Loss
Reducing body weight is considered an important therapeutic intervention to treat patients with type 2 diabetes and is a major challenge in ambulatory settings. Most intervention trials have failed to demonstrate a long lasting effect. A carbohydrate-restricted diet in comparison with three other dietary interventions, lower in fat and higher in carbohydrates, showed that the most beneficial effect in weight reduction was in those patients treated.
Read also: Safety of Low-Carb Diets During Lactation
Potential Role in Cancer Treatment
Glucose (sugar) is thought to be a contributor to tumor growth. A clinical trial is evaluating the tolerability of a ketogenic diet in conjunction with metformin and whether maintaining the diet with metformin will have any effect on tumor.
Important Considerations and Potential Risks
Nutrient Deficiencies
In nutrient levels, the ketogenic diet provided less fiber; thiamin; vitamins B6, C, D and E; and phosphorus. "The lower in carbs you go, the more you're wiping out entire food groups that are considered very nutrient dense and healthy," he said, noting that to achieve an extreme restriction of carbohydrates, the ketogenic diet prohibits legumes, fruits and whole grains.
LDL Cholesterol Increase
Each diet had one other statistically significant benefit: LDL cholesterol increased on the keto diet and decreased on the Mediterranean diet - a point for Mediterranean.
Keto Flu and Dehydration
Following a low-carb, high-protein diet, such as the keto diet, can increase the risk of dehydration, as well as electrolyte imbalances. This happens because when the body stores carbohydrates, it stores water along with it. In response to reduced blood sugar levels, the body doesn’t produce as much insulin. In turn, the kidneys expel both water and sodium from the body. Proper hydration helps support steadier blood sugar levels. These dehydration symptoms are a part of the so-called keto flu that often afflicts new low-carb dieters.
Lactic Acidosis
Rarely, metformin may cause a build-up of lactic acid in the body. If the levels get too high, a serious, potentially fatal condition known as lactic acidosis can occur. Lactic acidosis is a medical emergency. Signs and symptoms can include flushing (sudden reddening), feelings of warmth on the skin, dizziness, nausea, vomiting, heart rate changes, and muscle pain.
Read also: Best keto-friendly chips
Medication Adjustments
Your diabetes care team can help you determine the right low-carb approach for you. It’s also important to notify them of any diet or lifestyle changes to avoid any potential side effects. In fact, they may recommend lowering or changing your medications to avoid very low blood sugar levels (hypoglycemia), cardiovascular complications, and diabetic ketoacidosis (DKA), which is a health emergency. This is especially true if you’re taking insulin, insulin-promoting drugs, or blood pressure medications, Urbanski says. Additionally, SGLT2 inhibitors, oral medications that assist the kidneys in lowering blood sugar levels, may push some people into potentially fatal DKA. Eating a low-carb diet can further exacerbate that risk.
Vitamin B12 Deficiency
For some people, metformin may lead to vitamin B12 deficiency or anemia over time. Your healthcare provider will monitor your lab work for changes. They may suggest a vitamin B12 supplement or injections, as well as other nutrients like iron or calcium, which may also be depleted from metformin.
Dietary Guidelines While Taking Metformin
Foods to Limit or Avoid
- Alcohol: Metformin interacts with alcohol, so avoid binge drinking or regular alcohol intake when on the medication.
- Simple and Refined Carbs: Metformin helps the body reduce blood sugar, but it doesn’t work effectively if you eat a lot of foods that make blood glucose levels spike. Refined or processed carbs have little fiber and can rapidly increase blood sugar levels. So can foods high in sugar. As much as possible, avoid white bread, white rice, white pasta, candy, soda, desserts, and snacks like chips or crackers.
- Saturated Fat: Diabetes is a chronic condition that increases the risk of inflammatory disorders like cardiovascular disease. Saturated fats can increase inflammation in the body and may make it harder to lose weight or manage diabetes. They can also contribute to imbalanced lipids. Red meat and dairy products (milk, butter, cheese, etc.) are common sources of saturated fat. You don’t have to avoid all dairy, but focus on low-fat options.
- Trans Fat: Many store-bought baked goods or restaurant fast foods contain trans fats.
- Too Much Sodium: Diabetes can increase the risk for hypertension and heart problems. Most Americans eat an excessive amount of salt, which can also increase the risk of high blood pressure.
Foods to Incorporate
- Complex Carbohydrates: Unrefined grains such as brown rice, whole grain oats, whole-grain bread, and quinoa contain fiber. Fiber slows the rate at which your body converts carbs into glucose, leading to more stable blood glucose levels.
- Healthy Fats: A low-fat diet is important, and the type of fat also matters.
- Fiber: Most Americans don’t get enough fiber. This nutrient supports a healthy digestive tract, good blood sugar levels, and weight loss. Aim for 25-30 grams per day from whole grains, fruits, and vegetables. You can also try a fiber supplement if you struggle to eat enough fiber, but check with your medical provider.
- Low-Carb Fruits: While all fruits contain beneficial nutrients, eating lower-carb fruits is better for glucose balance.
Practical Tips for Following a Low-Carb Diet with Metformin
Explore All Your Low-Carb Diet Options: There is no universally agreed upon recommendation for how many carbs to eat on a low-carb diet.
Communicate Regularly With Your Healthcare Team: Your diabetes care team can help you determine the right low-carb approach for you. It’s also important to notify them of any diet or lifestyle changes to avoid any potential side effects.
Monitor Your Blood Sugar: While a low-carb diet can help stabilize your blood sugar, it’s still important to monitor it carefully to prevent periods of hyperglycemia or hypoglycemia.
Read also: Best Keto Tortillas
Focus on Carb Quality: A low-carb diet shouldn’t just be about what you cut. It should also be about what you add into your nutrition plan.
Spread Out Carb Intake: If you eat too few carbs at each meal, you may have difficulty sustaining this diet long-term. You may end up reaching for high-carb snacks during the day, which can cause large dips and spikes in your blood sugar levels.
Prioritize Fiber Intake: Fiber is critical to overall health: It lowers blood pressure, improves insulin health, and encourages weight loss by stabilizing blood sugar and increasing satiety.
Drink Plenty of Water: Following a low-carb, high-protein diet, such as the keto diet, can increase the risk of dehydration, as well as electrolyte imbalances.