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Published on: January 7, 2018
Effect of Calorie-Unrestricted Low-Carbohydrate, High-Fat Diet Versus High-Carbohydrate, Low-Fat Diet on Type 2
Camilla Dalby Hansen1, Eva-Marie Gram-Kampmann2, Johanne Kragh Hansen3
1Department of Gastroenterology and Hepatology, Odense University Hospital, and Institute of Clinical Research, University of Southern Denmark, Odense, Denmark (C.D.H., M.B.H., N.T., M.K., S.J., K.H.T., M.S.T.).
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 A1c (mean difference in change, -6.1 mmol/mol [95% CI, -9.2 to -3.0 mmol/mol] or -0.59% [CI, -0.87% to -0.30%]) and lost more weight (mean difference in change, -3.8 kg [CI, -6.2 to -1.4 kg]). Both groups had higher high-density lipoprotein cholesterol and lower triglycerides at 6 months. Changes in low-density lipoprotein cholesterol were less favorable in the LCHF diet group than in the HCLF diet group (mean difference in change, 0.37 mmol/L [CI, 0.17 to 0.58 mmol/L] or 14.3 mg/dL [CI, 6.6 to 22.4 mg/dL]). No statistically significant between-group changes were detected in the assessment of NAFLD. Changes were not sustained at the 9-month follow-up.
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.
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