Is the Keto Diet Healthy for Diabetes?
By Patrick Sullivan
The keto diet may be appropriate for some, but others should avoid it. For people with type 1 diabetes trying the diet, extra monitoring for blood sugar and ketones is critical.
When you have diabetes, you hear “count your carbs” constantly. The ketogenic diet cuts carbs drastically to change the normal way your body processes and uses energy. Sounds like your carb-counting questions are answered, right?
Not exactly.
While the keto diet can be an effective eating strategy for managing your glucose and getting to and staying at a healthy weight, it’s not quite so simple. Anyone taking insulin needs to take special precautions before starting on low carb diets like keto.
Thinking about giving the keto diet for diabetes a shot? Here’s what you need to know.
What exactly is the keto diet?
The keto diet is a very low carbohydrate diet with typically 10% or less of daily calories. For 2,000 calories a day, that’s 50 grams or less worth of carbs. Fat makes up about 55-60%, with protein around 30-35%.
The low-carb content supports the keto diet’s main feature: ketosis.
“Low carbs cause the body to break down stored fat into its backup energy source – ketones – after the body’s stored glucose supply is used up,” explained Annette Snyder, a nutritionist and registered dietician.
Normally, the hormone insulin brings glucose from the blood into cells where it’s used for energy. But because of its low carb content, the keto diet induces a state called ketosis, which is when there’s not enough glucose to use for fuel or insulin to bring glucose into cells.
During ketosis, your liver breaks fat down into fatty acids and turns these acids into ketone bodies, a process called ketogenesis. These ketones are used for energy by your cells in the same way as glucose is used for energy.
Benefits of the keto diet for diabetes
While the keto diet isn’t for everyone, research does show some benefits for diabetes management like improved A1C and glycemic control.
In a study of 363 people – 102 of whom had type 2 diabetes – a ketogenic diet was better than a standard low-calorie diet for improving blood glucose, weight, and cholesterol. Another small study of adults with type 2 diabetes and obesity showed similar results, with the keto diet being more effective for weight loss and glucose control.
“Any time you lose weight, it can improve related clinical measurements like A1C,” said Snyder. “The very low intake of carb foods with keto also means lower intake of foods with strong impacts on blood glucose levels. Lower glucose levels over time equals lower A1C.”
One possible reason for improved diabetes management is the need for insulin is less, given the restricted amount of carbohydrates, Snyder added.
Considerations and complications
Although a keto diet can help you lose weight and better manage your blood sugar, it's very much not a set-it-and-forget-it eating pattern – especially if you have diabetes. For anyone on the keto diet, you may have to contend with important nutritional deficits, as well as potentially risky low blood sugar episodes.
Nutrition concerns
The very low-carb nature of the keto diet means sacrificing certain macro- and micronutrients necessary for general health. Snyder said that one drawback to the keto diet is inadequate fiber intake.
Fiber is beneficial for glucose management as it doesn’t cause blood sugar spikes the same way other foods might. It’s also good for your heart. If trying the keto diet, Snyder added that you may need to supplement with thiamin and other vitamins including B6, C, D, and E.
Hypoglycemia
The keto diet may reduce your body’s insulin requirements, according to some research. That’s one of the benefits of the keto diet for diabetes, but the downside is it can lead to hypoglycemic episodes in some people, especially those with type 1 diabetes. A continuous glucose monitor (CGM) may be very helpful in preventing hypoglycemia.
“Those with type 1 and type 2 diabetes dependent on insulin will need to be especially cautious when reducing carbs to the level required for ketosis, as insulin will lower their blood sugar even if it’s in the normal range,” said Snyder. “There is a risk for hypoglycemia if insulin is not adjusted appropriately.”
Ketosis vs. ketoacidosis
Ketosis simply means your body is creating ketones from stored fat. But, these fatty acid-based ketones can make your blood dangerously acidic if they build up too much. If there’s also a buildup of blood glucose at the same time, that can put you into a potentially life-threatening state known as diabetic ketoacidosis (DKA).
Researchers acknowledge that ketoacidosis on the keto diet for people with type 1 diabetes is a real concern. A meter to measure blood ketones can be very helpful for people with type 1 diabetes on a keto diet. For example, the Precision Xtra Meter can measure both glucose and ketones.
“Close monitoring of ketones, blood sugar patterns, and medications are important in preventing a critical situation like ketoacidosis,” said Snyder.
If you have type 1 diabetes or insulin-dependent type 2 diabetes, speak to a healthcare provider before trying the keto diet on your own.
Heart health
Another concern of the keto diet for people with diabetes is cholesterol. The keto diet can cause spikes in cholesterol, sometimes dramatically, studies have found. Too much cholesterol, especially LDL (the bad kind; think “L” for “lousy”), can increase your risk of heart attacks and other forms of heart disease. However, there are medications like statins that can lower your LDL cholesterol and reduce the risk of heart problems.
Where to start with the keto diet
So, the keto diet sounds intriguing, you’ve talked it over with your healthcare providers, and you’re ready to monitor your glucose and ketones. How do you get started?
Snyder said it’s usually a small jump to the keto diet from most diabetes-friendly diets. However, keep in mind that the keto diet is a lot stricter and might be more difficult to maintain long-term compared to other healthy eating patterns like the Mediterranean diet.
Snyder recommends the following food sources for starting on the keto diet:
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Carbs: Aim for vegetables as much as possible, though whole grains, legumes, and fruit can work in small doses.
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Protein: Lean meats, fish, nuts, and seeds as opposed to saturated fat-laden meats like sausage and bacon.
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Healthy fats: Nuts, seeds, some oils (like olive oil), again avoiding sources of saturated fat.
Foods to avoid (or limit) on the keto diet include bread, pasta, alcohol, sugary drinks (including fruit juice), and starchy vegetables like potatoes. Snyder reminds people trying the keto diet that they may have to supplement with fiber and multivitamins.
The bottom line
Further research is needed on the efficacy and safety of the ketogenic diet in those with type 1 diabetes. The very low carb diet may be appropriate for select people, but only after a thorough discussion with their healthcare team about the risks and benefits.
If you have access to a registered dietitian or specialist in diabetes care, they should always be part of any discussion when it comes to diets. For some people, the keto diet may help with weight loss and blood sugar control. For type 1 patients on the keto diet, extra monitoring is critical, preferably with a CGM and a blood ketone meter.
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