The report1  based on survey data that reveal that a very low–carbohydrate diet (VLCD) might be effective in some patients with type 1 diabetes mellitus may represent an important advance in the therapy of this condition if researchers in randomized clinical trials confirm its potential advantages in terms of better blood glucose control with less risk for hypoglycemia. However, there are several issues of concern. One is the general use of the term “very low–carbohydrate dieting” to describe the diet when there are in fact 2 distinct forms.

One type of ketogenic diet is the very low–calorie diet, or semistarvation ketogenic diet,2,3  which is severely hypocaloric and provides <800 kcal per day and usually <400 kcal per day and is intended for the weight loss phase in the medical treatment of obesity. When these diets to allow for starvation ketosis (which reduces hunger) occur, 0 to <50 g of carbohydrates are provided, and dietary fat intake is markedly reduced.

A second type of ketogenic diet, called a eucaloric ketogenic diet,4  is also used to restrict carbohydrate intake to a similar degree but contains substantially more total calories because fat is intended to provide sufficient energy to allow growth in children while helping to establish seizure control, maintain weight and athletic performance in adults of a normal weight,4  and recently, allow modest weight loss in moderate-to-severe obesity complicating type 2 diabetes mellitus by reducing hunger with improved glucose control and reduced medication use.5  To avoid confusion, the diet described in the present article should be viewed as being in the second category.

A second concern is that although no greater risk of adverse events was noted from the survey, there should be clinical concern in subsequent trials that patients who have mild starvation ketosis with lower ambient serum insulin levels could develop diabetic ketoacidosis more rapidly with the onset of intercurrent illness and the development of insulin resistance, although there is some experimental evidence in animals that β-hydroxybutyrate has substantial anti-inflammatory activity.6 

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Competing Interests

CONFLICT OF INTEREST: I am a consultant to Virta Health, which is studying ketogenic diets in type 2 diabetes mellitus.