Effect of Calorie-Unrestricted Low-Carbohydrate, High-Fat Diet Versus High-Carbohydrate, Low-Fat Diet on Type 2 Diabetes and Nonalcoholic Fatty Liver Disease : A Randomized Controlled Trial.

BACKGROUND

It remains unclear if a low-carbohydrate, high-fat (LCHF) diet is a possible treatment strategy for type 2 diabetes mellitus (T2DM), and the effect on nonalcoholic fatty liver disease (NAFLD) has not been investigated.

OBJECTIVE

To investigate the effect of a calorie-unrestricted LCHF diet, with no intention of weight loss, on T2DM and NAFLD compared with a high-carbohydrate, low-fat (HCLF) diet.

DESIGN

6-month randomized controlled trial with a 3-month follow-up. (ClinicalTrials.gov: NCT03068078).

SETTING

Odense University Hospital in Denmark from November 2016 until June 2020.

PARTICIPANTS

165 participants with T2DM.

INTERVENTION

Two calorie-unrestricted diets: LCHF diet with 50 to 60 energy percent (E%) fat, less than 20E% carbohydrates, and 25E% to 30E% proteins and HCLF diet with 50E% to 60E% carbohydrates, 20E% to 30E% fats, and 20E% to 25E% proteins.

MEASUREMENTS

Glycemic control, serum lipid levels, metabolic markers, and liver biopsies to assess NAFLD.

RESULTS

The mean age was 56 years (SD, 10), and 58% were women. Compared with the HCLF diet, participants on the LCHF diet had greater improvements in hemoglobin A

LIMITATION

Open-label trial, self-reported adherence, unintended weight loss, and lack of adjustment for multiple comparisons.

CONCLUSION

Persons with T2DM on a 6-month, calorie-unrestricted, LCHF diet had greater clinically meaningful improvements in glycemic control and weight compared with those on an HCLF diet, but the changes were not sustained 3 months after intervention.

PRIMARY FUNDING SOURCE

Novo Nordisk Foundation.