More evidence shows low carb benefits blood sugar control for those with type 2 diabetes


Low-carb nutrition has become a well-recognized intervention when it comes to controlling blood sugar, especially for those with type 2 diabetes. It’s now endorsed by the ADA, Diabetes Canada, and other national institutions as an effective strategy.

This is mainly based on data showing that restricting carbs reduces hemoglobin A1c and improve daily average blood sugar.

Now, a small study from Denmark is pointing to lower-carb, higher-protein diets to improve blood sugar control. In fact, the findings show low-carb nutrition is superior to standard diabetes care for the degree of variation in blood sugar.

This so-called “glycemic variability“ has been associated with an increased risk of diabetes complications. Many believe that even with a “good” overall daily blood sugar reading, high variability (big swings for blood sugar highs and lows) independently increases the risk for complications.

The study involved 16 participants with type 2 diabetes taking metformin. They were randomized to eat a “low-carb high protein” diet (31% carbs, 29% protein, 40% fat) for two days, or a conventional diabetes diet (54% carbs, 16% protein, 30% fat) for two days. After a washout period, they then crossed over to eat the other diet.

They wore a continuous glucose monitor (CGM) for the duration of their experiment.

Keep in mind that a diet consisting of 31% carbohydrates is still not a true low-carb diet, comprised of about 140 grams of carbs for a 1,800 calorie diet. But it is significantly lower than the 54% carb diet which means consuming around 245 grams carbohydrates per day on a 1,800 calorie diet.

The study’s results were striking. Just about every measurement for blood sugar control was significantly better for those on the lower-carb, higher-protein diet. This includes postprandial glucose, mean glucose, glucose excursion, time spent in the glucose range, and multiple different measurements of glucose variability.

While this study was small (only 16 people), short in duration (only 48 hours), and tested a liberal low-carb diet (31% carbs), it still shows promising results for the effect of carbohydrate reduction on glycemic variability.

Perhaps even more important, this study also displays how a high protein intake (29% of calories or 137 grams on a 1,800 calorie diet) can beneficially impact blood sugar control.

As we detail in our guide on protein and low-carb diets, some in the low-carb sphere fear that higher protein intake can lead to increased gluconeogenesis (literally “making new glucose”) which will drive blood sugar levels higher.

This study, however, produced the opposite results. The higher protein diet showed better — not worse — blood sugar control.

We will add this to our growing list of studies showing improved blood sugar control with a lower carb, higher protein diet. As the evidence mounts, more and more healthcare practitioners will need to take note of this potentially powerful lifestyle intervention.

Are you interested in getting started with a low-carb diet? Check out our free two-week keto challenge, or our 5 weeks of keto program, where we supply you with all the information you need to get started and succeed at a low-carb lifestyle.
Thanks for reading,
Bret Scher, MD FACC


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