There is no absolute consensus on what defines a low carbohydrate diet; however the following categories are generally used.
Very low carbohydrate diet: 20-50g per day (< 10% of total energy intake)
Low carbohydrate diet: 130g carbohydrate per day (26% of total energy)
Moderate carbohydrate diet: 26-45% total energy intake
Why do people use low carb diets?
Low carbohydrate diets are often recommended and used for weight loss. Research has demonstrated the success of a low carbohydrate diet in promoting weight loss in both overweight adults and obese children. A 2014 review comparing popular weight loss diets in adults found a small difference between the effectiveness of the diets, suggesting that the composition of the diet is unlikely to be as important as the restriction of kilojoule intake and the ability to stick to the diet. One of the few studies undertaken in obese children found that a low carbohydrate diet was as effective as a portion controlled diet in achieving weight loss; however children were less able to stick to the low carbohydrate diet than the portion controlled diet.
Carbohydrate restriction is used by some individuals with type 1 diabetes to reduce glucose excursions after eating a meal. Lower carbohydrate meals require a lower dose of insulin, which in turn reduces the degree of error in insulin dosing and the likelihood of hyperglycaemia or hypoglycaemia.
However this is not the only way of reducing glucose fluctuations and improving glycaemic control. Children with Type 1 Diabetes are able to achieve HbA1c's less than 6.5% whilst consuming a carbohydrate intake making up 45-50% of their total energy requirements.
A recent review of a variety of diets for people with diabetes, including low carbohydrate, low glycaemic index (GI), Mediterranean and high protein, found that the improvements in HbA1c and lipid profiles seen from consuming a low carbohydrate diet were also seen in the Low GI and Mediterranean diets.
Low carbohydrate diets in children and adolescents
Currently there is no evidence to support the use of low carbohydrate diets in type 1 diabetes. International guidelines recommend that carbohydrates are NOT restricted in children and adolescence with type 1 diabetes, given the evidence to show that low carbohydrate diets in children can be nutritionally inadequate and impair growth.
Research has shown a negative association between lower carbohydrate intakes, BMI and percentage body fat. Glycaemic control has been shown to both improve and deteriorate with lower carbohydrate diets, highlighting the need for individualised care.
If you and your family have questions or would like further information around the use of low carbohydrate diets, or other strategies to improve glucose fluctuations around meals times the dietitians at PMH are very happy to work with you to ensure a nutritionally adequate diet that meets the goals of your family.