Very Low-Carb Diets and Children With Type 1 Diabetes: What a Huge New Study Shows

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What the researchers did

A team led by Professor Christian Denzer of Ulm University Medical Center in Germany and Dr. Belinda Lennerz of Boston Children's Hospital (Harvard Medical School) analyzed a diabetes follow-up registry covering 25 years. The results were presented at the EASD annual meeting in Milan, held from September 28 to October 2, 2026.

The analysis included 45,569 children and teenagers aged 1 to 17 with Type 1 diabetes. Their carbohydrate intake had been recorded at least twice over a year or longer. According to the organizers, it is the largest study of its kind.

The children were sorted into three groups by the share of daily calories that came from carbohydrates:

• Very low-carb: under 10 percent (219 children)
• Low-carb: 10 to under 26 percent (4,837 children)
• Standard: 26 percent or more (40,513 children)

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What they found

Children in the very low-carb and low-carb groups gained less body mass index (BMI) over time, so they stayed closer to a healthy weight.

Their long-term blood sugar levels (HbA1c, an average of the past two to three months) were also lower and rose more slowly. The same was true for the dose of basal insulin, the long-acting insulin that covers the body's needs between meals.

The researchers also looked at a combined score, IDAA1c, which weighs blood sugar against insulin dose. It was lower in the carb-restricted groups too. In plain terms, these children reached better blood sugar control without simply taking more insulin.

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Safety: no red flags, with limits

A major worry about strict diets in growing children is whether they harm development. The analysis found no evidence that very low-carb eating stunted growth. It also found no link to severe low blood sugar (hypoglycemia) or to diabetic ketoacidosis (DKA).

DKA is a dangerous emergency in which the body lacks enough insulin and the blood becomes acidic. It is not the same as ketosis, the state in which the body burns fat for fuel because few carbs are available. In ketosis, there is still enough insulin to keep ketones in check.

The very low-carb group was small, just 219 children, and was followed for about two years on average. Diet was self-reported, and the authors say other hidden factors could still have influenced the results.

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What experts say about the evidence

Dr. Lennerz called the results "very encouraging" but stressed that they remain observational. More research is needed to find the ideal carbohydrate amount that gives benefits while keeping food variety.

Earlier research points in a similar direction. A randomized crossover trial from Prague, published in 2024 in Diabetes Research and Clinical Practice, tested 35 children and young people. Each followed a lower-carb diet (about 95 grams a day) and a recommended-carb diet (about 191 grams a day) for five weeks each. Time spent in the target blood sugar range was higher on the lower-carb diet, 77.1 versus 73.8 percent.

A 2021 multi-center study in the journal Nutrients concluded that low-carb eating is not rare among children with Type 1 diabetes and is linked to modestly better disease control.

A 2025 review in Pediatric Endocrinology Diabetes and Metabolism adds a note of caution. It points out that scientific evidence in children is still limited. Doctors worry about cholesterol problems, low blood sugar, eating disorders and disrupted development, and general guidelines still recommend about 45 percent of daily calories from carbohydrates.

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Why medical supervision matters

Cutting carbs lowers the insulin a child needs. If the insulin dose is not adjusted, blood sugar can drop too far. For that reason, any change should be planned with the child's diabetes team, ideally including a pediatric endocrinologist and a dietitian experienced in Type 1 diabetes.

In practice, a very low-carb approach means sharply limiting foods such as bread, pasta, rice, cereal, fruit and sweets. It relies more on protein, fats and non-starchy vegetables.

Parents should not try this on their own, however promising the headlines sound.

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Outlook

The study adds weight to a debate that is growing as more parents try low-carb diets for children with Type 1 diabetes. Observational data cannot settle the question, and the authors themselves call for further research. Larger, long-term controlled trials will have to show which carbohydrate level is both effective and safe for growing children.

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Sources

1. European Association for the Study of Diabetes (EASD) press release, as published by News-Medical: https://www.news-medical.net/news/20261001/Very-low-carbohydrate-diets-show-potential-benefits-in-children-with-type-1-diabetes.aspx
2. Neuman V. et al., "Low-carbohydrate diet in children and young people with type 1 diabetes: A randomized controlled trial with cross-over design," Diabetes Research and Clinical Practice, 2024 (Charles University, Prague): https://www.lf2.cuni.cz/en/publications/low-carbohydrate-diet-in-children-and-young-people-with-type-1-diabetes-a-randomized
3. Odyjewska E. et al., "Current controversies surrounding low-carbohydrate diets in children with type 1 diabetes," Pediatric Endocrinology Diabetes and Metabolism, 2025: https://www.termedia.pl/Current-controversies-surrounding-low-carbohydrate-diets-in-children-r-nwith-type-1-diabetes,138,56721,0,1.html
4. "Low-Carbohydrate Diet among Children with Type 1 Diabetes: A Multi-Center Study," Nutrients, 2021: https://www.mdpi.com/2072-6643/13/11/3903/htm

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