Food Intake According to Clock Gene Polymorphisms: A Systematic Review

This systematic review investigated differences in daily energy intake among genotypes of circadian clock genes, potentially supporting personalized nutritional strategies for health. This topic can help develop personalized nutritional strategies for metabolic health by evaluating SNPs in circadian clock genes that may influence dietary intake. We searched the PubMed, EMBASE, and Cochrane Library databases following PRISMA guidelines and assessed the risk of bias using the Joanna Briggs Institute (JBI) tool (PROSPERO: CRD42024601530). Ten studies were included, involving 12,115 adult and elderly participants (mean age 40.8 ± 8.6 years; 60.6% women). Six studies investigated the SNP CLOCK rs1801260, while four analyzed the SNPs CLOCK rs4580704, CLOCK rs3749474, CRY1 rs2287161, and CRY2 rs11605924, with one study for each. Only one study found an association between the minor allele of CLOCK rs1801260 and increased energy, carbohydrate, and lipid intake, as well as later meal timing. Individuals with at least one risk allele (C) had higher intake and later mealtimes than those with the wild-type allele (TT). The inconsistent associations across studies may be attributed to methodological limitations, including dietary assessment, sample size, genetic model classification, population characteristics, and environmental factors, such as including dietary patterns, chronotype, night shift work, sleep, and meal timing. Future research should adopt more comprehensive approaches to better clarify the impact of circadian gene variants on eating behavior.