A genotype-guided nutritional intervention to reduce cardiometabolic risk factors in young adults: Study protocol for a randomized controlled trial

Abstract

Background & aims: Cardiometabolic diseases (CMD), including cardiovascular disease, obesity and diabetes, are major public health challenges influenced by lifestyle factors (e.g., diet), vitamin D status, and genetic predisposition. Single nucleotide polymorphisms (SNPs) contribute to genetic risk scores for CMD-related traits (M-GRS) and recent research suggests that genotype-based nutritional interventions have the potential to reduce these risks. This study aims to evaluate the effectiveness of genotype-guided nutritional interventions versus standard dietary recommendations in young adults.

Methods: This 12-month study includes a 6-month intervention phase and a 6-month free-living phase. Data will be collected at baseline, 3, 6 and 12 months. We plan to recruit young adults (aged 23-29) previously genotyped from the Obesity, Lifestyle, and Diabetes in Brazil (BOLD) study and randomized by BMI, sex, and M-GRS based on 34 SNPs. The control group will follow a standard Brazilian diet with CMD-related recommendations and 1000 IU of vitamin D3 daily. The personalized intervention group will receive a genotype-guided dietary plan based on gene-diet interactions for SNPs in the M-GRS, along with personalized vitamin D3 supplementation (1000 or 4000 IU) based on their genetic risk for deficiency (D-GRS). Body composition, biochemical markers and metabolomics will be assessed, with the reduction in body fat percentage as the primary outcome.

Discussion: This study will contribute to precision nutrition by assessing genotype-guided dietary recommendations for CMD risk management, potentially demonstrating how genetic information can optimize dietary interventions and reduce CMD burdens, improving overall health outcomes.