LCHF and HCLF diets both improve HRQoL in type 2 diabetes, with no significant between-group difference

BACKGROUND: Health-related quality of life (HRQoL) is a central aspect of overall health and a crucial factor in dietary interventions, as it may determine both dietary compliance and sustained adherence. OBJECTIVES: We assessed the effect on HRQoL between: 1) the low-carbohydrate high-fat (LCHF) diet and 2) the high-carbohydrate low-fat (HCLF) diet and evaluated the impact on dietary compliance and sustained adherence. METHODS: This is a prespecified secondary analysis from a randomized controlled trial in people with type 2 diabetes. Participants were randomly assigned 2:1 to follow either LCHF or HCLF for 6 mo with a postintervention visit 9 mo after inclusion. Liver biopsies were performed at baseline and after 6 mo, the Diabetes-39 HRQoL questionnaire, standard clinical and compliance assessments were conducted at baseline, 3 mo, 6 mo, and 9 mo (postintervention). Sustained adherence was assessed at the postintervention visit. RESULTS: We randomly assigned 165 participants; 96 (58%) were female. At baseline, the median age was 56 [interquartile range (IQR) 50-63] y, mean body mass index was 33 + 7 kg/m, total median HRQoL score was 88 (IQR, 70-111), mean hemoglobin A1c was 56+10 mmol/mol, and 141 (88%) had metabolic dysfunction-associated steatotic liver disease. After 6-mo intervention, HRQoL improved in both groups {LCHF: -14.5 [95% confidence interval (CI): -20.7, -8.36]; P < 0.001; HCLF; -13.7 (95% CI: -22.7, -4.6); P = 0.003} with no mean difference in change between groups (Δ) P = 0.855. Higher improvements in HRQoL were associated with a higher compliance with the diets (Spearman's rho; -0.183; P = 0.0378) and increased the likelihood of sustained adherence to the LCHF diet. CONCLUSIONS: HRQoL improved in both dietary intervention groups with no difference between groups. Dietary compliance was associated with improved HRQoL and may play a role in sustained adherence to the LCHF diet. This trial was registered at clinicaltrials.gov as NCT03068078.