Background: Physical fitness and a healthy body mass are important predictors of a good performance of military tasks. The purpose of this study was to assess the physical activity level and nutrition, in terms of the frequency of consumption of individual food groups, of Polish Navy soldiers and Maritime Unit of the Border Guard officers. Materials and Methods: This study was conducted on 131 Polish Navy soldiers aged 33.1 ± 6.3 years old and 132 Maritime Unit of the Border Guard officers aged 38.6 ± 5.5 years old. In order to carry out research on physical activity, the International Physical Activity Questionnaire was used. Eating habits were assessed based on a Food Frequency Questionnaire for 61 groups of food products. Results: Over 80% of the soldiers and officers studied indicated high levels of physical activity. Only 8.2% of soldiers and 4.3% of officers indicated a low level of physical activity. Of the 61 food product groups analyzed, significant differences were found in the frequency of consumption of 17 products. These differences concerned almost all groups (except dairy products and eggs). Conclusions: To summarize, soldiers and officers presented high and moderate levels of physical activity. Taking into account the demonstrated frequent consumption of high-energy and high-fat products, such as sausages and red meat, as well as margarine, mayonnaise, and sugar, with the low frequency of fruit and vegetable consumption in both studied groups, it is advisable to conduct training among soldiers and officers in the field of health education.