Low-carbohydrate diet in type 1 diabetes: A systematic review

Background: The treatment of type 1 diabetes mellitus (T1D) consists of applying insulins with different action profiles and ingesting known amounts of nutrients from the diet. Although there is no specific recommendation regarding the distribution of these macronutrients, low-carbohydrate (LC) diets seem to show promise in some types of diabetes, but their role in T1D is still controversial, given the potential glycemic improvement, but with the concurrent possibility of changes in other parameters such as lipids. This systematic review aimed to evaluate the metabolic effects of these diets on T1D. Methods: A systematic review in PubMed, Embase, and Lilacs with publications from the last 10 years was used as a data source. Results: Nine clinical trials were included. We have found LC diet to be associated with increased time in range in continuous glucose monitoring (+5.68 %, p = 0.01); decreased time below range (-0.53 %, p = 0.01 with 54 mg/dL threshold and-2.28 %; p = 0.01 with 70 mg/dL threshold), coefficient of variation (-5.51 %; p = 0.01), total insulin daily dose (-8.39 %; p = 0.01), and systolic blood pressure (-4.83 mmHg, p = 0.04). Conclusions: LC diets show potential benefit in metabolic control of people living with T1D, warranting the design of future robust clinical trials. (c) 2025 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.