Low- and no-carb diets could assist in type 2 diabetes management

The Centers for Disease Control (CDC) estimates more than 34 million Americans have diabetes, with type 2 accounting for 90-95% of all diagnosed cases. This number has more than doubled over the last 20 years, something the CDC attributes to an aging U.S. population and rising obesity crisis.

As the CDC notes, unlike many health conditions, individuals are able to play a role in their diabetes management, which includes improved diet and increased physical activity. A recent meta-analysis published in the BMJ—formerly the British Medical Journal—indicates a low- or no-carb diet could help push type 2 diabetes into remission, meaning an average blood sugar level over a three-month period that is below the threshold for diagnosing diabetes.

The meta-analysis, authored by Joshua Z. Goldberg et. al., sought to “determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes.” Ultimately, 23 trials consisting of nearly 1,400 participants were analyzed; of those, 40.6% of the outcomes were deemed to be at “low risk” of bias.

The analysis showed some promising results. At six months, “compared with control diets, LCDs achieved higher rates of diabetes remission,” with 57% of people on low-carb plans going into remission, versus 31% of people on other diets. However, by the one-year mark, most of those results had vanished.

“At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes,” the authors wrote. The same effect was noticed in regards to weight loss, with the authors noting, “Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months.”

While the mechanism behind the initial success at six months and diminishing effects at 12 months are not totally clear, Grant Brinkworth, one of the authors of the meta-analysis, believed the difficulty of adhering to a diet long-term could play a role. “Despite the benefits for blood-sugar control that very low-carb diets can offer, they can be very difficult to adhere to," noted Julie Stefanski, a registered dietitian and certified diabetes educator, on WebMD. Stefanski was not part of the study.

This could also be seen in the subgroup data between the LCD groups and VLCD groups.

“On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months,” the authors wrote. “However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs.”

Despite the 12-month results, the analysis should still offer hope for those looking to manage their type 2 diabetes. As the authors noted, the six-month results indicate a low- or no-carb diet could be an effective short-term option for kickstarting weight loss and better health, which in turn can assist in the treatment and management of type 2 diabetes.