Low carb diet may reduce type 2 diabetes risk, promote weight loss

The link between carbs and type 2 diabetes (T2D) is well-established, but new research suggests that cutting carbs could help minimize risk for those who may be susceptible to developing the condition.

The study, a random clinical trial (RCT) recently published in JAMA Network Open Diabetes and Endocrinology, found that a low carbohydrate diet promoted weight loss and improved fasting glucose levels in subjects who were at risk for developing T2D.

Lead author and epidemiologist Kirsten S. Dorans of Tulane University in New Orleans, LA, told Medical News Today:

“While low carb diets are often recommended for those with type 2 diabetes, little evidence has existed for whether eating fewer carbs can impact the blood sugar of those with mild diabetes or prediabetes who aren’t treated by medications. This study was conducted in people with blood sugar that ranged from prediabetes to mild diabetes levels who were not on diabetes medications.”

Lowering blood sugar with a low carb diet

Hemoglobin A1C is a widely used clinical term to measure long-term blood sugar levels.

According to the American Diabetes Foundation, a person who has prediabetes has A1C levels between 5.7 and less than 6.5%. Higher A1C levels may signify diabetes.

Dr. Dorans explained that subjects enrolled in the study had a hemoglobin A1C range of 6.0 to 6.9%. 

“This range chosen as the lower bound aligns with the World Health Organization’s lower cutoff point for prediabetes and the upper bound with less than the 7.0% American Diabetes Association hemoglobin A1C target,” she said.

For the study, 150 adults were recruited at a New Orleans academic center. The 6-month trial ran from September 2018 to June 2021. Participants ranged in age from 40 to 70 years old and were divided into two groups.

The first group was tasked with reducing their daily carbohydrate intake to less than 40 grams for the first 3 months and less than 60 grams from month 3 to the end of the trial.

“We found that nutritional counseling promoting a low-carbohydrate diet lowered hemoglobin A1C over 6 months,” Dr. Dorans said.

“In line with prior work, the low-carbohydrate diet group also lost substantial weight compared with the group of people who stayed with their usual diet.”

At the end of 6 months, Dr. Dorans and her research team found that A1C levels reduced by 0.23% more in the low carb group than the usual diet group.