ObjectivesHerein, we investigate the relationships between the COVID‐19 pandemic and overcoming the virus, and its effects on body composition parameters in young adults from Slovakia.MethodsWe assessed 773 adults aged 18 to 30 years in pandemic‐status sub‐groups. Individual lifestyles and overcoming the COVID‐19 effects were evaluated by a detailed questionnaire, and body composition parameters were analyzed using the InBody 770 bioimpedance analyzer.ResultsStatistically significant lower values were observed in the male group during the pandemic for the following parameters; proteins and minerals, fat free mass (FFM), skeletal muscle mass (SMM), lean body mass (LBM) and its values in the right and left arm and trunk, total body water (TBW) and its values in the right and left arm and trunk, body cell mass (BCM), basal metabolic rate (BMR) and phase angle (PA). The regression analysis confirmed the negative pandemic effect and the negative impact of COVID‐19 on men in the following parameters: proteins (p = .027 for pandemic and p = .005 for COVID‐19), FFM (p = .023 for pandemic and p = .005 for COVID‐19), LBM (p = .022 for pandemic and p = .004 for COVID‐19), SMM (p = .028 for pandemic and p = .005 for COVID‐19), TBW (p = .020 for pandemic and p = .004 for COVID‐19), BMR (p = .024 for pandemic and p = .005 for COVID‐19) and PA (p = .009 for pandemic). Physical activity was a further significant predictor in men for all the above parameters.ConclusionsWe observed significantly lower body composition parameters associated with fat free mass in young adult men during the pandemic than before it. However, future research is warranted to determine if these effects have long‐term significance.