Association between the rs17782313 polymorphism near the MC4R gene, ultra-processed food consumption, and postpartum weight retention: Preliminary results

Abstract

Objective

To investigate the association between the MC4R rs17782313 polymorphism, ultra-processed food (UPF) consumption, and postpartum weight retention (PPWR).

To investigate the association between the MC4R rs17782313 polymorphism, ultra-processed food (UPF) consumption, and postpartum weight retention (PPWR).

Methods

This study included adult women (=20 years) between 6 and 12 months postpartum whose most recent pregnancy resulted in a singleton birth. Participants were recruited at Gaffrée e Guinle University Hospital (HUGG), Rio de Janeiro, Brazil, between March 2024 and October 2025. Women who were pregnant at the time of data collection, diagnosed with HIV infection, or unable to complete the interview were excluded. Data were collected using a structured questionnaire covering sociodemographic characteristics and clinical and obstetric history. UPF consumption on the previous day was assessed according to the Brazilian Ministry of Health guidelines. Weight and height were measured, while pre-pregnancy weight was self-reported. PPWR was calculated as the difference between current and pre-pregnancy weight. Genotyping of the rs17782313 polymorphism was performed by real-time PCR using genomic DNA extracted from saliva samples. Statistical analyses were performed using SPSS version 25. Continuous variables were described as medians and interquartile ranges (IQR) and compared using the Mann-Whitney U test. Categorical variables were expressed as frequencies and compared using Pearson's chi-square test. Statistical significance was set at P < 0.05. The study was approved by the Research Ethics Committee (CAAE 70713423.8.0000.5258; approval no. 6.273.645).

This study included adult women (=20 years) between 6 and 12 months postpartum whose most recent pregnancy resulted in a singleton birth. Participants were recruited at Gaffrée e Guinle University Hospital (HUGG), Rio de Janeiro, Brazil, between March 2024 and October 2025. Women who were pregnant at the time of data collection, diagnosed with HIV infection, or unable to complete the interview were excluded. Data were collected using a structured questionnaire covering sociodemographic characteristics and clinical and obstetric history. UPF consumption on the previous day was assessed according to the Brazilian Ministry of Health guidelines. Weight and height were measured, while pre-pregnancy weight was self-reported. PPWR was calculated as the difference between current and pre-pregnancy weight. Genotyping of the rs17782313 polymorphism was performed by real-time PCR using genomic DNA extracted from saliva samples. Statistical analyses were performed using SPSS version 25. Continuous variables were described as medians and interquartile ranges (IQR) and compared using the Mann-Whitney U test. Categorical variables were expressed as frequencies and compared using Pearson's chi-square test. Statistical significance was set at P < 0.05. The study was approved by the Research Ethics Committee (CAAE 70713423.8.0000.5258; approval no. 6.273.645).

Preliminary results

Among 160 women, 67.5% had the TT genotype, 26.3% the CT genotype, and 6.3% the CC genotype. The prevalence of PPWR was 58.1%, with a median retention of 6.0 kg (IQR: 3.0–10.5). No significant difference in PPWR was observed between TT and CT/CC genotypes (5.9 kg [IQR: 3.0–11.0] vs. 6.9 kg [IQR: 3.2–8.8], P = 0.818). Regarding UPF consumption, 40.6% of participants reported consuming hamburgers or processed meats, 15.6% consumed packaged snacks or instant noodles, and 73.8% consumed sugar-sweetened beverages on the previous day. No significant associations were found among PPWR, rs17782313 genotypes, and UPF consumption.

Among 160 women, 67.5% had the TT genotype, 26.3% the CT genotype, and 6.3% the CC genotype. The prevalence of PPWR was 58.1%, with a median retention of 6.0 kg (IQR: 3.0–10.5). No significant difference in PPWR was observed between TT and CT/CC genotypes (5.9 kg [IQR: 3.0–11.0] vs. 6.9 kg [IQR: 3.2–8.8], P = 0.818). Regarding UPF consumption, 40.6% of participants reported consuming hamburgers or processed meats, 15.6% consumed packaged snacks or instant noodles, and 73.8% consumed sugar-sweetened beverages on the previous day. No significant associations were found among PPWR, rs17782313 genotypes, and UPF consumption.

Conclusion

PPWR showed a high prevalence in this population; however, it was not associated with the rs17782313 polymorphism or UPF consumption. Further analyses considering additional variables, potential confounders, and gene-diet-environment interactions are needed to better understand the determinants of PPWR and support future Precision Nutrition strategies for women of reproductive age.

PPWR showed a high prevalence in this population; however, it was not associated with the rs17782313 polymorphism or UPF consumption. Further analyses considering additional variables, potential confounders, and gene-diet-environment interactions are needed to better understand the determinants of PPWR and support future Precision Nutrition strategies for women of reproductive age.