Clinical Outcomes in T2D: Low-Carbohydrate vs Calorie-Restricted Diet

Individuals with type 2 diabetes (T2D) placed on a low-carbohydrate diet (LCD; 130 g/d) may not experience additional benefits in lowering glycated hemoglobin (HbA_1c) or body mass index (BMI) 1 year after completing a 6-month dietary intervention compared with individuals on a calorie-restricted diet (CRD), according to a study by Hormone Research in Pediatrics.

Researchers identified 66 individuals with T2D who were randomly assigned to an LCD (n=22) or CRD (n=27) for 6 months. Clinical (HbA_1c and BMI) and nutritional data were collected on participants 1 year after the intervention to determine whether the benefits of being placed on the LCD diet persisted after the 6-month intensive intervention. Participants continued outpatient visits during the 1 year after the intensive intervention and were free to manage their own diet during that year.

Study results demonstrated a comparable carbohydrate intake between those on a CRD and those on an LCD (median, 215 g/d [interquartile range, 189-243 g/d]; and median, 214 g/d [interquartile range, 176-262 g/d], respectively). In addition, both groups experienced a decrease in HbA_1c (CRD: median, −0.4% [interquartile range, −0.9% to 0.3%]; and LCD: median, −0.35% [interquartile range, −1.0% to 0.35%]) and BMI (CRD: median, −0.63 kg/m² [interquartile range, −1.20 to 0.18 kg/m²]; and LCD: median, −0.77 kg/m² [interquartile range, −1.15 to −0.12 kg/m²]) when compared with baseline data. However, there was no difference in HbA_1c or BMI observed between those on a CRD or an LCD.

The researchers concluded that the beneficial effects of reducing HbA_1c and BMI did not persist 1 year after completing an intense 6-month dietary intervention in those placed on an LCD compared with those on a CRD. However, participants on both diets experienced a significant improvement (reduction) in their HbA_1c and BMI compared with their baseline values.

Therefore, clinicians should consider the use of either a CRD or an LCD in patients with T2D, as they are effective and well-constructed nutrition therapy programs that were equally effective in lowering HbA_1c and BMI at least 1 year after initiation.

Reference

Sato J, Kanazawa A, Hatae C, et al. One year follow-up after a randomized controlled trial of a 130 g/day low-carbohydrate diet in patients with type 2 diabetes mellitus and poor glycemic control. PLoS One. 2017;12:e0188892