Sport of higher achievements requires hard training from athletes in a hard time mode for many years. Therefore, it is very important to monitor the diet of athletes. The aim of this research is development of a complex herbal antioxidant that can be used to increase the quality of the oils, fats and fat-containing products included in the diet. The current state of the use of antioxidants is assessed. The features of plant and synthetic antioxidants are described. The development of antioxidant is carried out from such plant materials as walnut leaves and calendula flowers. The chemical composition of the active antioxidant substances of walnut leaves and calendula flowers is given. The methods used in the work are aimed at obtaining extracts, estimating rational extraction parameters, and testing the antioxidant abilities of the extracts from periods of induction of products with different fatty acid composition. It is also used to plan and process the results of a full factorial experiment, to develop a technology for stabilizing fat-containing products to oxidation processes. It is proved that the developed complex antioxidant can increase the stability of food products to oxidation processes, protecting the product from the accumulation of free radicals. The rational parameters of the process of extraction of antioxidant substances from the studied plant materials are indicated. Data from induction periods, by which the quality of the extracts was assessed, is obtained using the Oxy test device. Synergism between tocopherols and antioxidant substances of walnut leaf extracts and calendula flowers is studied. The effectiveness of the antioxidant in relation to the products of different fatty acid composition is shown, which gives the right to use the antioxidant in a wide range of fat-containing products. A scheme for the stabilization of vegetable oils by the developed antioxidant is proposed. Recommendations on the enrichment of the diet of athletes by developed antioxidant are given