Effects of a low-carbohydrate diet on insulin-resistant dyslipoproteinemia-a randomized controlled feeding trial

• Main Authors: Ebbeling, C.B (Author), Greco, K.F (Author), Johnson, A. (Author), Knapp, A. (Author), Ludwig, D.S (Author), Ma, C. (Author), Mora, S. (Author), Wong, J.M.W (Author)
• Format: Article
• Language: English
• Published: NLM (Medline) 2022
• Subjects: adolescent; Adolescent; adult; Adult; aged; Aged; blood; body mass; Body Mass Index; body weight loss; cardiovascular disease risk factors; Cholesterol, HDL; Cholesterol, LDL; complication; controlled study; Diet, Carbohydrate-Restricted; Diet, Reducing; dietary trial; dyslipidemia; Dyslipidemias; female; Female; high density lipoprotein cholesterol; human; Humans; insulin; Insulin; insulin resistance; Insulin Resistance; intention to treat analysis; Intention to Treat Analysis; low calorie diet; low carbohydrate diet; low density lipoprotein cholesterol; low-carbohydrate diet; macronutrients; male; Male; middle aged; Middle Aged; obesity; Obesity; procedures; randomized controlled trial; saturated fat; treatment outcome; Treatment Outcome; triacylglycerol; Triglycerides; Weight Loss; young adult; Young Adult
• Online Access: View Fulltext in Publisher

 BACKGROUND: Carbohydrate restriction shows promise for diabetes, but concerns regarding high saturated fat content of low-carbohydrate diets limit widespread adoption. OBJECTIVES: This preplanned ancillary study aimed to determine how diets varying widely in carbohydrate and saturated fat affect cardiovascular disease (CVD) risk factors during weight-loss maintenance. METHODS: After 10-14% weight loss on a run-in diet, 164 participants (70% female; BMI = 32.4 ± 4.8 kg/m2) were randomly assigned to 3 weight-loss maintenance diets for 20 wk. The prepared diets contained 20% protein and differed 3-fold in carbohydrate (Carb) and saturated fat as a proportion of energy (Low-Carb: 20% carbohydrate, 21% saturated fat; Moderate-Carb: 40%, 14%; High-Carb: 60%, 7%). Fasting plasma samples were collected prerandomization and at 20 wk. Lipoprotein insulin resistance (LPIR) score was calculated from triglyceride-rich, high-density, and low-density lipoprotein particle (TRL-P, HDL-P, LDL-P) sizes and subfraction concentrations (large/very large TRL-P, large HDL-P, small LDL-P). Other outcomes included lipoprotein(a), triglycerides, HDL cholesterol, LDL cholesterol, adiponectin, and inflammatory markers. Repeated measures ANOVA was used for intention-to-treat analysis. RESULTS: Retention was 90%. Mean change in LPIR (scale 0-100) differed by diet in a dose-dependent fashion: Low-Carb (-5.3; 95% CI: -9.2, -1.5), Moderate-Carb (-0.02; 95% CI: -4.1, 4.1), High-Carb (3.6; 95% CI: -0.6, 7.7), P = 0.009. Low-Carb also favorably affected lipoprotein(a) [-14.7% (95% CI: -19.5, -9.5), -2.1 (95% CI: -8.2, 4.3), and 0.2 (95% CI: -6.0, 6.8), respectively; P = 0.0005], triglycerides, HDL cholesterol, large/very large TRL-P, large HDL-P, and adiponectin. LDL cholesterol, LDL-P, and inflammatory markers did not differ by diet. CONCLUSIONS: A low-carbohydrate diet, high in saturated fat, improved insulin-resistant dyslipoproteinemia and lipoprotein(a), without adverse effect on LDL cholesterol. Carbohydrate restriction might lower CVD risk independently of body weight, a possibility that warrants study in major multicentered trials powered on hard outcomes. The registry is available through ClinicialTrials.gov: https://clinicaltrials.gov/ct2/show/NCT02068885. © The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.