People have been observing the beneficial effect of food on human health and wellbeing since the dawn of mankind. Healthy eating is still a relevant topic in our modern age. The development of new technologies and scientific advancements gave new insights and impulse for further development in the field of nutritional science. The Project of Human Genome provided new opportunities for researches in nutritional sciences linking it to genomic blueprint of an individual and giving rise to the new field of nutrigenomics, which studies interactions between human genes and diet. Nutrigenomic testing and counselling available on the market offers personalization of diet based on gene variants an individual has. In this thesis, commercially available nutrigenomics testing and counselling service was used to obtain a personalized diet and compare to diet personalization obtained through classical nutritional assessment using a five-day diet diary, anthropometric measurements and a short questionnaire on eating habits. The aim of the study was to determine whether nutrigenomic counselling justifies its higher price and ultimately, whether there are differences between nutrigenomical and classical nutrition counselling. Both approaches provided a similar recommendation for improving the existing diet. A nutritionist who uses the classical approach can personalise the diet of a cooperative individual just as well as a nutritionist who relies on the results of a nutrigenomical analysis.