The input of molecular genetic biomarkers allows individual assessment of metabolic pathways and the behaviour of the major enzymes responsible for nutrient conversion. This in turn enriches the nutrigenetic information fund, and the panels of well-studied gene variants and their interaction with nutrients can be used to create precise personalized diets. Our objective was to determine the significance of the rs174547 genetic variant in the fatty acid desaturase 1 (FADS1) gene in the metabolism of saturated and unsaturated fatty acids ingested with food and to identify the potential of FADS1 rs174547 as a molecular genetic marker to be included in a panel of nutrigenetic studies in order to prepare a personalized diet plan. A total of 123 volunteers (43 men and 80 women) from Bulgaria, aged 28 to 65 years, were tested for rs174547 in the FADS1 gene. A DNA sample was taken from each volunteer by a non-invasive method (buccal swabs), and the genetic variant of each individual was determined by molecular genetic approaches. Their general health was assessed by taking anthropometric and body impedance measurements data and completing a lifestyle survey. The lipid profile included testing for triglycerides, total cholesterol, HDL and LDL cholesterol, and blood sugar. Information on the total food intake was collected through questionnaire methods. The results of the statistical tests show that there is a statistically significant difference between the two genotypes only in HDL cholesterol levels (P = 0.044, at P < 0.05) - carriers of the C/T genotype have lower mean concentration values of HDL-cholesterol (1.27 mmol/l) than for T/T variant carriers (1.48 mmol/l). Among men, there were statistically significant differences in mean levels of total cholesterol (P = 0.012) and HDL cholesterol (P = 0.008) between the two genotypes. Among women, there was a statistically significant difference between the two genotypes only in terms of mean triglyceride levels (P = 0.007). The differences in the other studied indicators do not satisfy the criterion for significance (P < 0.05). The results suggest an effect of the intake of SFA (saturated fatty acids) and MUFA (monounsaturated fatty acids) on the relationship between rs174547 polymorphism and plasma lipids (total and LDL-cholesterol) only in men. Studies of the Bulgarian population prove extremely low intake of omega-3 fatty acids due to low consumption of fish. These findings and the lack of data for Bulgaria on genetic variants of FADS1 are a prerequisite for conducting in-depth studies of both risk groups, such as patients with cardiovascular disease, dyslipidaemia or nutritional deficiency of LC-PUFAs, and in healthy people.