How a Low-Carb Diet Might Aid People With Type 1 Diabetes

Andrew has Type 1 diabetes, and six years ago, in order to control his blood sugar levels, his parents put him on a low-carbohydrate, high-protein diet. His mother makes him recipes with diabetic-friendly ingredients that won’t spike his blood sugar, like pizza with a low-carb, almond-flour crust; homemade bread with walnut flour instead of white flour; and yogurt topped with blueberries, raspberries and nuts.

Andrew’s diet requires careful planning — he often takes his own meals with him to school. But he and his parents say it makes it easier to manage his condition and, since starting the diet, his blood sugar control has markedly improved and he has not had any diabetes complications requiring trips to the hospital.

“I do this so that I can be healthy,” Andrew, who lives with his parents in Jacksonville, Fla., said of his diet. “When I eventually move out and go to college, I’m going to keep up what I’m doing because I’m on the right path.”

Most diabetes experts do not recommend low-carb diets for people with Type 1 diabetes, especially children. Some worry that restricting carbs can lead to dangerously low blood sugar levels, a condition known as hypoglycemia, and potentially stunt a child’s growth. But a new study published in the journal Pediatrics on Monday suggests otherwise.

It found that children and adults with Type 1 diabetes who followed a very low-carb, high-protein diet for an average of just over two years — combined with the diabetes drug insulin at smaller doses than typically required on a normal diet — had “exceptional” blood sugar control. They had low rates of major complications, and children who followed it for years did not show any signs of impaired growth.

The study found that the participants’ average hemoglobin A1C a long-term barometer of blood sugar levels, fell to just 5.67 percent. An A1C under 5.7 is considered normal, and it is well below the threshold for diabetes, which is 6.5 percent.

“Their blood sugar control seemed almost too good to be true,” said Belinda Lennerz, the lead author of the study and an instructor in the division of pediatric endocrinology at Boston Children’s Hospital and Harvard Medical School. “It’s nothing we typically see in the clinic for Type 1 diabetes.”

The new study comes with an important caveat. It was an observational study, not a randomized trial with a control group. The researchers recruited 316 people, 130 of them children whose parents gave consent, from a Facebook group dedicated to low-carb diets for diabetes, called TypeOneGrit, then reviewed their medical records and contacted their medical providers.

While it was not a clinical trial, the study is striking because it highlights a community of patients who have been “extraordinarily successful” at controlling their diabetes with a very low-carb diet, said Dr. David M. Harlan, the co-director of the Diabetes Center of Excellence at the UMass Memorial Medical Center, who was not involved in the study. “Perhaps the surprise is that for this large number of patients it is much safer than many experts would have suggested.”