Moderate Carbohydrate Diet May Improve Glucose Control in Patients With T1D

A moderate carbohydrate diet could help adults with type 1 diabetes improve glucose control compared to a more traditional diet with higher amounts of carbohydrates, according to new research published in The Lancet Regional Health – Europe.¹

For patients with type 1 diabetes, diet is a crucial aspect of reaching glycemic targets, which is associated with a lower risk of complications. While certain diets are known to protect against cardiovascular risk, most recommendations for people with diabetes have focused on type 2 diabetes.

“All patients should find the diet that suits them, in consultation with their healthcare professionals, but there has been a lack of sufficiently large studies randomizing participants to different experimental treatments of this kind,” Marcus Lind, professor of diabetology at the University of Gothenburg and an author on the study, said in a release.²

Investigators from the University of Gothenburg in Sweden conducted a study to investigate if a moderate carbohydrate diet improves glucose control in people with type 1 diabetes. Data was gathered from a randomized, multicenter, open-label, crossover trial over 12 weeks.

The study cohort included 50 participants with a mean baseline HbA1c of 69 mmol/mol. The participants were put on a moderate carbohydrate diet where 30% of total energy came from carbohydrates or a traditional diet where 50% of total energy came from carbohydrates. The intervention lasted a total of 4 weeks, followed by a 4-week washout period.

To evaluate the impact of the 2 diets on glucose control, investigators used masked continuous glucose monitoring. The primary study endpoint was difference in mean glucose levels between the last 14 days of each diet phase.

Investigators found that the difference in mean glucose levels between moderate carbohydrate and traditional diet was −0.6 mmol/L. Participants who were on the moderate carbohydrate diet increased their time in range by 4.7% and decreased their time above range by 5.9%. Mean ketone levels were 0.17 mmol/L during traditional diet and 0.18 mmol/L during moderate carbohydrate diet.

There were no significant differences in the standard deviation of glucose levels or hypoglycaemia in the range <3.9 mmol/L and <3.0 mmol/L. Additionally, no serious adverse events were observed through the study period, including severe hypoglycaemia and ketoacidosis.

Investigators noted that 1 possible mechanism for decreases in glucose levels and other positive effects from the moderate carbohydrate diet could be due to fewer glucose changes.

“A moderate low-carbohydrate diet can be a good treatment option for adults with type 1 diabetes with elevated glucose levels,” Sofia Sterner Isaksson, lead author on the study, said in a release.² “However, it is important that the diet is healthy with a particular focus on fat and carbohydrate quality, and that the amount of carbohydrates is not too low so it can be considered safe.”

References

1. Sterner Isaksson S, Ólafsdóttir AF, Ivarsson S, et al. The effect of carbohydrate intake on glycaemic control in individuals with type 1 diabetes: A randomised, open-label, Crossover Trial. Lancet Reg Health Eur. Published online 2023:100799. doi:10.1016/j.lanepe.2023.100799

2. Moderate low-carbohydrate diet is beneficial for adults with type 1 diabetes. News Release. University of Gothenburg. December 20, 2023. Accessed January 4, 2024. https://www.gu.se/en/news/moderate-low-carbohydrate-diet-is-beneficial-for-adults-with-type-1-diabetes