Because the main tenet of the keto diet is counting and cutting carbs — a commonly used way to control blood sugar — this eating approach has become increasingly popular among people with type 2 diabetes who are looking to lower their A1C, which is the two- to three-month average measurement of blood sugar levels. Indeed, research suggests this diet may lead to fast weight loss and potentially lower blood sugar for people with the disease. (13)
Other forms of ketogenic diets include cyclic ketogenic diets, also known as carb cycling, and targeted ketogenic diets, which allow for adjustments to carbohydrate intake around exercise. These modifications are typically implemented by athletes looking to use the ketogenic diet to enhance performance and endurance and not by individuals specifically focused on weight loss.
The gist of the eating plan? Taking in so few carbs sends your body into ketosis—a state of burning fat for energy, instead of carbohydrates or sugars, explains Beth Warren, RDN, founder of Beth Warren Nutrition and author of Secrets of a Kosher Girl: A 21-Day Nourishing Plan to Lose Weight and Feel Great (Even If You're Not Jewish). In order to stay in ketosis, you only consume 5% to 10% of your calories from carbohydrates—which for most followers is fewer than 20 grams total per day—and instead eat moderate amounts of protein and high amounts of fat.
There are three instances where there’s research to back up a ketogenic diet, including to help control type 2 diabetes, as part of epilepsy treatment, or for weight loss, says Mattinson. “In terms of diabetes, there is some promising research showing that the ketogenic diet may improve glycemic control. It may cause a reduction in A1C — a key test for diabetes that measures a person’s average blood sugar control over two to three months — something that may help you reduce medication use,” she says.