Interactions between Total Energy, and Protein Intake, and the MC4R rs17782313 Variant on Lipid Levels in Saudi Adults: A Cross-Sectional Study.

Introduction: Genetic variations, including rs17782313 (C/T) in the MC4R gene, are associated with lipid levels. Gene-diet interactions contribute to disease development. This study aimed to investigate the effects of interactions between total energy intake, protein intake, and MC4R rs17782313 on lipid parameters in Saudi adults.

Methods: In a cross-sectional study of 268 Saudi adults (aged 20-55 years), dietary data were assessed using a 136-item validated semiquantitative food frequency questionnaire, and MC4R (rs17782313) was genotyped using real-time polymerase chain reaction.

Results: Total energy and protein calorie intake interacted with the MC4R rs17782313 polymorphism to influence total cholesterol (TC) (p_interaction = 0.036 and p_interaction = 0.021, respectively). Low total energy and protein intake was associated with decreased TC levels in all genotypes at rs17782313. The interaction between total energy intake and MC4R rs17782313 affected triglyceride levels (p_interaction = 0.039). Protein calorie intake significantly interacted with MC4R rs17782313 in determining low-density lipoprotein (p_interaction = 0.042). However, none of these interactions remained significant after applying Bonferroni correction (p > 0.01).

Conclusion: Low total energy and protein intake is associated with low lipid levels among all genotypes at rs17782313 in Saudi adults. Further validation in larger cohorts is warranted to confirm these findings and explore their clinical implications.