Association of MC4R Gene Variants with Body Fat, Diet, and Stress in Obese Young Adults: A Cross-Sectional Study

Abstract

Introduction: Melanocortin-4 receptor (MC4R) gene plays a central role in appetite regulation and energy homeostasis. However, limited evidence exists on interactions between MC4R gene-polymorphisms (rs12970134) and lifestyle factors in obese individuals.

Objectives: Analytical cross-sectional study investigated association of MC4R gene-polymorphism with body composition, dietary patterns, and perceived stress levels among obese young adults.

Methods: Total 60 obese individuals of both genders aged 18–25 years were enrolled. Participants were screened and categorized based on Asia-Pacific BMI classification. Anthropometric measurements and body composition were assessed using bioelectrical impedance analysis, dietary intake was evaluated using food frequency questionnaire, stress was measured using Perceived Stress Scale and MC4R genotyping was performed using Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR-RFLP).

Results: BMI was 34.37±5.88 kg/m², with mean body fat mass (BFM) of 42.08±12.88 kg and percent body fat (BF%) of 48.58±7.87%. Genotype allele distribution GG (46.7%), GA (41.7%) and AA (11.7%) was in Hardy-Weinberg equilibrium. AA genotype individuals showed higher BMI, BFM, and BF% compared to GG and GA genotypes. A significant negative correlation was observed between MC4R genotype and total fat intake (p=0.018), while no associations were found with BMI or BFM. About 70% participants reported moderate stress which correlated insignificantly with BMI and BFM.

Conclusions: MC4R gene-polymorphism in young obese individuals do not show association with anthropometric indicators. However, significant associations with dietary fat intake suggests the role of gene-polymorphism in appetite-regulation pathways thereby influencing food preferences. Large sample studies are needed to elucidate gene–environment interactions in obesity.