according to a new clinical report.
Citing a lack of high-quality data and potential for adverse effects with carbohydrate restriction among younger individuals, lead author Anna Neyman, MD, of Indiana University, Indianapolis, and colleagues suggested that pediatric patients with type 2 diabetes should focus on reducing nutrient-poor carbohydrate intake, while those with type 1 diabetes should only pursue broader carbohydrate restriction under close medical supervision.
“There are no guidelines for restricting dietary carbohydrate consumption to reduce risk for diabetes or improve diabetes outcomes in youth,” the investigators wrote in Pediatrics. “Thus, there is a need to provide practical recommendations for pediatricians regarding the use of low-carbohydrate diets in patients who elect to follow these diets, including those with type 1 diabetes and for patients with obesity, prediabetes, and type 2 diabetes.”
Their new report includes a summary of the various types of carbohydrate-restricted diets, a review of available evidence for these diets among pediatric patients with type 1 and type 2 diabetes, and several practical recommendations based on their findings.
Dr. Neyman and colleagues first noted a lack of standardization in describing the various tiers of carbohydrate restriction; however, they offered some rough guidelines. Compared with a typical, balanced diet, which includes 45%-65% of calories from carbohydrates, a moderately restrictive diet includes 26%-44% of calories from carbohydrates, while a low-carb diet includes less than 26% of calories from carbs. Further down the scale, very low-carb diets and ketogenic diets call for 20-50 g of carbs per day or less than 20 g of carbs per day, respectively.
“There is evidence from adult studies that these diets can be associated with significant weight loss, reduction in insulin levels or insulin requirements, and improvement in glucose control,” the investigators noted. “Nevertheless, there is a lack of long-term safety and efficacy outcomes in youth.”
They went on to cite a range of safety concerns, including “growth deceleration, nutritional deficiencies, poor bone health, nutritional ketosis that cannot be distinguished from ketosis resulting from insulin deficiency, and disordered eating behaviors.”
“Body dissatisfaction associated with restrictive dieting practices places children and adolescents at risk for inadequate dietary intake, excessive weight gain resulting from binge-eating after restricting food intake, and use of harmful weight-control strategies,” the investigators wrote. “Moreover, restrictive dieting practices may negatively impact mental health and self-concept and are directly associated with decreased mood and increased feelings of anxiety.”
Until more evidence is available, Dr. Neyman and colleagues advised adherence to a balanced diet, including increased dietary fiber and reduced consumption of ultra-processed carbohydrates.
“Eliminating sugary beverages and juices significantly improves blood glucose and weight management in children and adolescents,” they noted.
For pediatric patients with type 1 diabetes, the investigators suggested that low-carb and very low-carb diets should only be pursued “under close diabetes care team supervision utilizing safety guidelines.”
Lack of evidence is the problem
David Ludwig, MD, PhD, codirector of the New Balance Foundation Obesity Prevention Center, Boston Children’s Hospital, and professor of pediatrics at Harvard Medical School, also in Boston, said the review is “rather general” and “reiterates common, although not always fair, concerns about carbohydrate restriction.”
courtesy Boston Children's Hospital
Dr. David Ludwig
“The main issue they highlight is the lack of evidence, especially from clinical trials, for a low-carbohydrate diet in children, as related to diabetes,” Dr. Ludwig said in a written comment, noting that this is indeed an issue. “However, what needs to be recognized is that a conventional high-carbohydrate diet has never been shown to be superior in adults or children for diabetes. Furthermore, whereas a poorly formulated low-carb diet may have adverse effects and risks (e.g., nutrient deficiencies), so can a high-carbohydrate diet – including an increase in triglycerides and other risk factors comprising metabolic syndrome.”
He said that the “main challenge in diabetes is to control blood glucose after eating,” and a high-carb makes this more difficult, as it requires more insulin after a meal than a low-carb meal would require, and increases risk of subsequent hypoglycemia.
For those interested in an alternative perspective to the AAP clinical report, Dr. Ludwig recommended two of his recent review articles, including one published in the Journal of Nutrition and another from the Journal of Clinical Investigation. In both, notes the long history of carbohydrate restriction for patients with diabetes, with usage dating back to the 1700s. Although the diet fell out of favor with the introduction of insulin, Dr. Ludwig believes that it needs to be reconsidered, and is more than a passing fad.
“Preliminary research suggests that this dietary approach might transform clinical management and perhaps normalize HbA1c for many people with diabetes, at substantially reduced treatment costs,” Dr. Ludwig and colleagues wrote in the JCI review. “High-quality randomized controlled trials, with intensive support for behavior changes, will be needed to address this possibility and assess long-term safety and sustainability. With total medical costs of diabetes in the United States approaching $1 billion a day, this research must assume high priority.”
This clinical report was commissioned by the AAP. Dr. Ludwig received royalties for books that recommend a carbohydrate-modified diet.
This article was updated 9/20/23.