Myth 1: People with diabetes should eat a low-carbohydrate diet

A debated issue is the ideal intake of carbohydrate to facilitate glycemic control in persons with diabetes.

Continue Reading

Two studies reported the association between actual carbohydrate intake and hemoglobin A1C (HbA1c) levels in persons with type 2 and type 1 diabetes.7,4 In both studies, patients who reported a higher intake of total fat and saturated fatty acids and a lower intake of carbohydrate had the poorest glycemic control.

Contrary to common advice to restrict carbohydrate intake, individuals with type 1 diabetes should be advised to limit their intake of saturated fatty acids and to consume nutrient-dense carbohydrates such as fruits, whole grains, and vegetables, while taking appropriate insulin doses as needed, found the study authors.4

Studies comparing lower levels of carbohydrate intake to higher carbohydrate intake report mixed effects on HbA1C levels and cardiovascular risk factors.8  Many of these studies are small, of short duration, and/or have low retention rates. Furthermore, in many of the studies, weight loss occurred, confounding the interpretations of results from changes in macronutrient content.

As a result, the American Diabetes Association (ADA) position statement on diabetes nutrition therapy concluded that “evidence is inconclusive for an ideal amount of carbohydrate intake for people with diabetes. Collaborative goals should be developed with the individual with diabetes […] For good health, carbohydrate intake from vegetables, fruits, whole grains, legumes, and dairy products should be advised over intake from other carbohydrate sources, especially those that contain added fats, sugars, or sodium.”1

Of concern, is that when carbohydrate intake is restricted, total fat and especially saturated fat, usually increases. Epidemiologic data and clinical trials have reported that long-term higher total fat intake results in greater whole-body insulin resistance.9,10 In patients with diabetes, reducing saturated fat has been shown to improve insulin sensitivity.11,12

Bottom Line: Patients with diabetes are best advised to eat healthy carbohydrate foods in appropriate portion sizes for ALL foods including both low- or high-carbohydrate foods.