DiseasesType 1 diabetes — could fewer carbohydrates mean less insulin and less fear?
- prof. David Ludwig — Is Exceptional Control of Type 1 Diabetes Possible with a Low-Carb Diet?
- Low-carbohydrate diet in type 1 diabetes: A systematic review. · Clin Nutr ESPEN 2025
- Low-Carbohydrate Diet among Children with Type 1 Diabetes: A Multi-Center Study. · Nutrients 2021
- Low-Carb and Ketogenic Diets in Type 1 Diabetes: Efficacy and Safety Concerns. · Nutrients 2025
- Low-carbohydrate diets in type 1 diabetes: balancing benefits and risks. · Curr Opin Endocrinol Diabetes Obes 2023
- Association between low-carbohydrate-diet score, glycemia and cardiovascular risk factors in adults with type 1 diabetes. · Nutr Metab Cardiovasc Dis 2024
- Association between low-carbohydrate diet scores and macrovascular events or all-cause mortality in adults with type 1 diabetes in Japan. · J Diabetes Investig 2026
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Prof. David Ludwig says these diets are not currently recommended for type 1 diabetes because of concerns about ketoacidosis, severe hypoglycemia, and impaired growth in children.
- It is not known whether they are safe and effective over the long term, and the findings do not justify changing treatment on your own.
- Prof. David Ludwig recommends discussing any dietary change with the person managing your diabetes care.
What the authors write
Low-carbohydrate diets are not currently recommended for type 1 diabetes because of concerns about ketoacidosis, severe hypoglycemia, and impaired growth in children.
The long-term safety and effectiveness of very-low-carbohydrate diets have not been established in the broader population of people with type 1 diabetes.
The findings suggest that much better diabetes control may be possible, but they do not by themselves justify changing treatment.
Anyone with diabetes should discuss any dietary change with their diabetes care provider.
Prof. David Ludwig says that before insulin was discovered, a very-low-carbohydrate, high-fat diet was the most effective treatment for severe diabetes.
Research from PubMed · Europe PMC
We selected 6 studies with the best, positive results. This is a selection, not a full review of all research.
Total number of studies on this topic in PubMed: 244.
The review found that a low-carbohydrate diet was associated with more time in the target glucose range, less glucose variability, and a lower insulin dose.
Aim of the study: 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.
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). LC diets show potential benefit in metabolic control of people living with T1D, warranting the design of future robust clinical trials.
“Not stated” does not mean nobody paid — the database does not always record it.
Children on a low-carbohydrate diet had lower average blood glucose and spent more time in the target range than children in the comparison group.
Aim of the study: The proportion of children with type 1 diabetes (T1D) who have experience with low-carbohydrate diet (LCD) is unknown. Our goal was to map the frequency of LCD among children with T1D and to describe their clinical and laboratory data.
Results: A total of 624/1040 (60%) of the subjects completed the survey. A total of 242/624 (39%) subjects reported experience with voluntary carbohydrate restriction with 36/624 (5.8%) subjects currently following the LCD. The LCD group had similar HbA1c (45 vs. 49.5, p = 0.11), lower average glycemia (7.0 vs. 7.9, p = 0.02), higher time in range (74 vs. 67%, p = 0.02), lower time in hyperglycemia >10 mmol/L (17 vs. 20%, p = 0.04), tendency to more time in hypoglycemia <3.9 mmol/L(8 vs. 5%, p = 0.05) and lower systolic blood pressure percentile (43 vs. 74, p = 0.03). The groups did not differ in their lipid profile nor in current body height, weight or BMI. The LCD was mostly initiated by the parents or the subjects themselves and only 39% of the families consulted their decision with the diabetologist. Low carbohydrate diet is not scarce in children with T1D and is associated with modestly better disease control.
“Not stated” does not mean nobody paid — the database does not always record it.
The review suggests that carbohydrate restriction may improve blood glucose control, but study findings vary and more data are needed.
Aim of the study: Despite advances in technology, the overall management of type 1 diabetes mellitus (T1DM) remains suboptimal. The idea of restricting carbohydrate intake to decrease glycemic spikes and insulin requirements has been revisited in recent years.
Results: In general, carbohydrate restriction enhances glycemic control by reducing postprandial glucose excursions, improving time-in-range, and lowering HbA1c, with conflicting effects on other parameters such as lipid profile and body weight. Adverse effects such as hypoglycemia and diabetic ketoacidosis are rarely reported, although some concerns have been raised regarding growth in children. The correct implementation of these diets requires a multidisciplinary approach by highly specialized healthcare professionals, who will address the medical, social, and psychological concerns that a restrictive diet entails. Large-scale and long-term studies are needed to provide more robust data before carbohydrate restriction can be widely applied to patients with T1DM.
“Not stated” does not mean nobody paid — the database does not always record it.
The review describes improvements in HbA1c, time in the target range, and glucose variability in many studies, but also notes possible risks.
Aim of the study: Interest in the use of calorie restriction with low-carbohydrate diets for patients with type 1 diabetes appears to be increasing despite physicians' discomfort about its longer term outcomes. A divergence in opinion regarding the balance of benefits and safety may lead to patient disengagement from conventional medical supervision.
Results: Benefits on glycaemia are observed in many studies, with improved HbA1c, time within target range and reduced glycaemic variability. A characteristic lipid profile with high LDL cholesterol is observed in many patients, but association with future cardiovascular events is undefined. A negative impact on growth has been identified in the paediatric population, and impact on mental health and disordered eating is of theoretical concern, without measurement in clinical studies.
“Not stated” does not mean nobody paid — the database does not always record it.
In a study of adults, lower carbohydrate intake was associated with more frequent achievement of an HbA1c of 7% or less.
Aim of the study: Low-carbohydrate-diets (LCDs) are gaining popularity in individuals with type 1 diabetes (T1D). However, the impact of such diets on glycemia and cardiovascular risk factors is debated. This study aims to evaluate associations between low-carbohydrate intakes using LCD score with glycemia and cardiovascular risk factors (lipid profile) in adults with T1D or LADA in Québec, Canada.
Results: This is a cross-sectional study using data collected in the BETTER registry (02/2019 and 04/2021) including self-reported 24-h dietary recalls to calculate LCD scores, waist circumference, level-2 and level-3 hypoglycemic episodes and measured biochemical data (HbA1c, LDL-cholesterol and non-HDL-cholesterol). Participants were divided into quartiles (Q) based on LCD scores. Two hundred eighty-five adults (aged 48.2 ± 15.0 years; T1D duration 25.9 ± 16.2 years) were included. Categorical variables underwent Chi-squared/Fisher's Exact tests, while continuous variables underwent ANOVA tests. Mean carbohydrate intake ranged from 31.2 ± 6.9% (Q1) to 56.5 ± 6.8% (Q4) of total daily energy. Compared to Q4, more people in Q1 reported HbA1c ≤ 7% [≤53.0 mmol/mol] (Q1: 53.4% vs. Q4: 29.4%; P = 0.011). The same results were found in the models adjusted for age, sex and T1D duration. A greater proportion of participants in Q1 never experienced level-3 hypoglycemia compared to Q3 (Q1: 60.0% vs.
“Not stated” does not mean nobody paid — the database does not always record it.
Among adults with type 1 diabetes, higher low-carbohydrate diet scores were associated with a lower risk of macrovascular events or death.
Aim of the study: The effects of lifestyle factors on macrovascular events or all-cause mortality remain unclear in type 1 diabetes. We examined the associations of diet, physical activity, and sleep with these outcomes among adults with type 1 diabetes living in Japan.
Results: Mean age was 51.4 ± 15.1 years, mean HbA1c was 7.9 ± 1.1%, and carbohydrate accounted for 49.3% of energy intake. During follow-up, 35 participants experienced the primary composite outcome. In multivariable Cox models, the Total LCDS (HR, 0.90; 95% CI: 0.82-0.98; P = 0.012), Plant LCDS (HR, 0.85; 95% CI: 0.76-0.94; P = 0.003), and Animal LCDS (HR, 0.93; 95% CI: 0.87-0.996; P = 0.037) were inversely associated with the outcome. Among adults with type 1 diabetes living in Japan, low-carbohydrate dietary patterns, particularly the Plant low-carbohydrate diet score, were inversely associated with macrovascular events or all-cause mortality.
“Not stated” does not mean nobody paid — the database does not always record it.
Perspectives and opinion materials
The content below presents the authors’ opinions, interpretations and hypotheses. It is not treated as equal to scientific studies and systematic reviews.
Pisaczek does not judge who is right. It shows what was written and where to read it. Every sentence above has its source.