The keto diet may help diabetes patients manage their symptoms by cutting carbs and replacing the calories with fats.
Startup company Virta Health has led pilot programs showing that blood sugar levels can be reduced to pre-diabetic levels on keto.
However, some experts are concerned with potential unknown side effects of keto in the long-term, including on cholesterol levels.
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The high fat, low carbohydrate keto diet may be able to treat patients with diabetes, according to research.
Companies like Virta Health are testing the diet as a treatment for veterans, in partnership with the US Department of Veterans' Affairs (VA), based on evidence that the diet can manage blood sugar and ease symptoms.
Here's how it works.
Keto could reduce symptoms of diabetes by managing blood glucose, but it isn't a cure
Diabetes is an inability to balance blood sugar. When you eat carbohydrates, the body converts them into glucose, which raises blood sugar. Normally, the body is able to produce enough insulin to balance blood sugar levels, but in the case of diabetics, the body doesn't produce enough (in type 1 diabetes) or has become resistance to its effects (type 2 diabetes).
Reducing carbs manages the problem at the source by preventing blood sugar from rising in the first place, according to Dr. Mark Cucuzzella, a professor at West Virginia University School of Medicine, a US Air Force Reservist, and a marathon runner who has published several studies on keto and diabetes.
"The most impactful thing on your blood glucose is the amount of carbs in your diet. The low-carb diet is effective because it lowers the insulin load," Cucuzzella, who is not affiliated with Virta, told Insider in an interview. "Insulin is the master switch."
Medications, including injections of insulin, can help mitigate diabetes symptoms by helping to manage blood sugar levels. But keto can help patients reduce medications, said Dr. Sarah Hallberg, medical director for Virta. Eating carbohydrates causes blood sugar to rise, but eating fats does not. It means diabetic patients can get their daily calories without needing to use insulin to balance out spiking blood sugar levels.
"Standard treatment puts people on a one-way street of progression for diabetes, with temporary pharmaceutical treatment that will have to be added on to," Hallberg told Insider. "We're able to give people another lane going the other way by bringing blood sugar into non-diabetic range while reducing and eliminating medication."
However, that doesn't mean keto can cure diabetes.
Virta refers to its treatment as a "reversal" of diabetes. In layman's terms, this means the disease is in remission, Cucuzzella said. The treatment only works as long as the low-carb diet is maintained. As soon as carbs are re-introduced, the same problems with blood sugar and insulin emerge.
What makes a good keto meal plan
A keto diet is any eating plan that pushes the body into a state of ketosis — when it begins producing substances called ketones, explained Dr. Ethan Weiss, a cardiologist and founder of a ketone-detecting device. (Weiss previously served as a medical advisor for Virta.)
"Keto" typically refers to eating plans in which a majority of daily calories come from fat, some protein, and 5%-30% of daily calories from carbohydrates. It's often described as a way for people to slim down without sacrificing rich foods like butter, bacon, and burgers.
People with diabetes could cut their carbs intake to as low as 30 grams a day and still be healthy. (For comparison, a medium-sized banana has about 27 grams of carbs.)
But the key to medical keto is going beyond macronutrients fats, carbs, and protein which occur in the context of foods — exactly what you eat in a day is just as important as counting the number of carbs.
This is what Hallberg refers to as a "well-formulated ketogenic diet," focused on whole-food sources of fats, and designed to cut carbs without completely eliminating sacrificing nutrient-rich foods like veggies. According to Hallberg, this means at least 5 servings a day of non-starchy vegetables, healthy fat sources like olive oil, and definitely not bacon for every meal.
"The idea that this is all meat sticks and heavens knows what else is not true," she said.
This is in contrast to some fad forms of keto, or those without medical supervision, that involve heaps of bacon, cheese, and even fast food, sometimes called "dirty" keto. These types of diets eliminate carb-containing nutritious foods like fruits and starchy vegetables and replace them with low-quality fats, which is concerning to nutritionists.
Critics say 'enthusiasm outpaces evidence' when it comes to long-term effects of keto
It's not clear what long-term health effects the keto diet might have.
Writing in an editorial for JAMA Internal Medicine, Dr. Shivam Joshi said "enthusiasm outpaces evidence" when it comes to keto.
The Physicians Committee for Responsible Medicine, a group of medical experts who advocate a plant-based diet, sent a letter to VA officials asking them to reconsider the partnership, and keto treatment, based on evidence that a high-fat, low-carb diet could potentially increase risks of diabetes, particularly diets high in saturated fat.
Skeptics have also noted that most of the data showing keto can treat diabetes is based on studies led and funded by Virta itself. There is barely any hard data on keto's health effects beyond two years on the diet.
However, keto advocates have noted that the quality of health outcomes on keto greatly depends on what's included in the diet, and that focusing on healthier unsaturated fats might be a way to convey the benefits with fewer risks.
Weiss, as a cardiologist who follows a keto diet, said that rising levels of "bad" cholesterol is indeed a potential issue for keto. Research may be starting to suggest otherwise, but Weiss said he's not willing to risk going against conventional wisdom about saturated fats just yet.
"There's no evidence that LDL cholesterol after keto diet is dangerous, but I'm not waiting around to take that chance," Weiss said. "There are many ways to do that diet, and people don't have to eat all that saturated fat."
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