Diet quality and biochemical parameters in individuals with type 2 diabetes across BMI categories: A cross-sectional...

Type 2 diabetes mellitus (T2DM) is closely associated with obesity and metabolic disturbances. Although diet quality has been linked to metabolic outcomes, its role relative to adiposity remains unclear. This study aimed to evaluate differences in biochemical parameters across body mass index (BMI) categories and examine relationships between diet quality and biochemical markers.

This cross-sectional study included 150 individuals with T2DM aged 46-60 years attending an endocrinology outpatient clinic between September 2023 and May 2024. Participants were classified as being of normal weight, overweight, or obese based on BMI. Diet quality was assessed using three-day food consumption records and calculated using the Healthy Eating Index-2015 (HEI-2015). Biochemical parameters were obtained from medical records. Between-group comparisons were performed using one-way ANOVA with Bonferroni post hoc tests and Pearson correlation analysis was used to assess associations. Benjamini-Hochberg false discovery rate (BH-FDR) correction was applied for multiple testing.

Several biochemical parameters differed significantly across BMI categories (p <0.05). Obese individuals had higher triglyceride, uric acid, C-reactive protein, liver function, and fasting insulin levels, whereas normal-weight individuals had higher high-density lipoprotein cholesterol and estimated glomerular filtration rate. No significant differences were observed in HEI-2015 scores across BMI groups (p >0.05). Weak correlations between diet quality and biochemical markers were not significant after BH-FDR correction.

Biochemical parameters differed across BMI categories, highlighting the role of adiposity in metabolic risk. Associations between diet quality and biochemical markers were limited, suggesting that BMI-based stratification may be more informative than diet quality alone.