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.
Study Goal
The researchers aimed to compare the effects of a high-carbohydrate, low-fat (HCLF) diet versus a low-carbohydrate, high-fat (LCHF) diet on glycemic control and nonalcoholic fatty liver disease (NAFLD) in individuals with type 2 diabetes mellitus (T2DM).
Results Summary
The HCLF diet showed less improvement in glycemic control and weight loss compared to the LCHF diet, but changes in low-density lipoprotein cholesterol were less favorable in the LCHF group. No significant differences were found in NAFLD assessment, and improvements were not sustained after the intervention ended.
Population
165 participants with type 2 diabetes mellitus (mean age 56 years, 58% women).
Effective Dosage
HCLF diet with 50-60% carbohydrates, 20-30% fats, and 20-25% proteins.
Duration
6-month intervention with a 3-month follow-up.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low-carbohydrate, high-fat (LCHF) diet | decrease | hemoglobin A1c | participants with T2DM | 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%] | greater improvements in | #1 |
low-carbohydrate, high-fat (LCHF) diet | decrease | weight | participants with T2DM | mean difference in change, -3.8 kg [CI, -6.2 to -1.4 kg] | lost more | #2 |
low-carbohydrate, high-fat (LCHF) diet | increase | high-density lipoprotein cholesterol | participants with T2DM | - | higher | #3 |
low-carbohydrate, high-fat (LCHF) diet | decrease | triglycerides | participants with T2DM | - | lower | #4 |
low-carbohydrate, high-fat (LCHF) diet | increase | low-density lipoprotein cholesterol | participants with T2DM | 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] | less favorable changes in | #5 |
low-carbohydrate, high-fat (LCHF) diet | no change | NAFLD | participants with T2DM | - | no statistically significant between-group changes were detected in the assessment of | #6 |
low-carbohydrate, high-fat (LCHF) diet | decrease | glycemic control | Persons with T2DM | - | greater clinically meaningful improvements in | #7 |
low-carbohydrate, high-fat (LCHF) diet | decrease | weight | Persons with T2DM | - | greater clinically meaningful improvements in | #8 |
low-carbohydrate, high-fat (LCHF) diet | no change | glycemic control and weight | Persons with T2DM | - | changes were not sustained | #9 |
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.