The beneficial short-term effects of a high-protein/low-carbohydrate diet on glycaemic control assessed by continuous glucose monitoring in patients with type 1 diabetes.

Abstract

To compare the effects of three different but isocaloric dietary patterns, high-protein/low-carbohydrate (HPD) with 20% of calories as carbohydrates, Mediterranean/low glycaemic index (MED) with 40% carbohydrates, and a reference diet (REF) with 50% carbohydrates, in patients with type 1 diabetes (T1D). In a randomized crossover study, 15 patients with T1D were assigned to the three dietary patterns for three separate weeks, with 7-day washout periods in between. Continuous glucose monitoring was applied during the intervention periods. The primary outcome was glycaemic control, as measured by the percentage of time patients spent within the euglycaemic range (TIR70-140 mg/dl ). Other key glycaemic metrics were also investigated as secondary outcomes. TIR70-140 was not statistically different between HPD, MED and REF (p= .105). Pairwise analysis revealed a statistically significant difference between HPD and REF at the .05 level, which was not retained after applying Bonferroni correction (54.87% ± 14.11% vs. 48.33% ± 13.72%; p= .018). During the HPD period, 11 out of 15 participants spent more time within TIR70-140 compared with either the REF or MED. The HPD performed significantly better than the REF in terms of TIR70-180 (74.33% ± 12.85% vs. 67.53% ± 12.73%; p= .012), glycaemic variability (coefficient of variation: 36.18% ± 9.30% vs. 41.48% ± 8.69%; p= .016) and time spent in the hypoglycaemic range (TBR70 mg/dl ; median: 12, IQR: 16 vs. median: 14, IQR: 20; p= .007), whereas no statistically significant differences were observed between MED and HPD or REF. Compared with REF and MED, an HPD plan may have a positive impact on glycaemic control in patients with T1D. During the HPD, patients spent a shorter time in hypoglycaemia and exhibited lower glycaemic variability.