The comparative dynamics of lipids and some fatty acids in the muscles of mature females and males of threespine stickleback from the White Sea kept in aquariums under the conditions of experimental short-term fasting and subsequent renewal of nutrition under different feeding regimens was studied. The most significant differences and the selectivity of lipid utilization are demonstrated between females and males in the process of an aquarium experiment, including their fasting and various dietary regimens. The results indicate the ability of the metabolic systems of male stickleback muscles to rapidly recover and store the requisite level of lipids after the termination of fasting. The relatively constant level of total lipids during fasting in the muscles of females can be explained by its maintenance due to the priority, up to the full, use of energy lipids, as well as individual structural lipids. The increase of the cholesterol level in the muscles of males and females during fasting and after the resumption of nutrition is most likely due to increased gluconeogenesis and increased resistance of the organism. A specificity of the expenditure of certain physiologically significant polyunsaturated fatty acids was observed – docosahexaenoic in males and eicosapentaenoic in females, most probably due to their special physiological roles in the fish organism. The temporal changes in the content of different lipids and fatty acids during fasting and the investigated feeding resumption regimens differ, reflecting the physiological and biochemical status of the organism, as well as the functional role and significance of individual lipid groups in the organism.