Metabolic Syndrome Among Professional Soldiers of the Polish Air Force and Land Forces: Prevalence, Biochemical Profile, and Lifestyle Correlates—A Cross-Sectional Study

Background/Objectives: Data on metabolic syndrome (MetS) among Polish professional soldiers remain limited despite the health and fitness requirements of military service. This study determined MetS prevalence and examined its associations with laboratory parameters, diet, and physical activity among Polish Air Force and Land Forces personnel. Methods: This cross-sectional study included 259 professional soldiers (235 men, 24 women; mean age, 39.5 ± 9.3 years). MetS was diagnosed using harmonized AHA/NHLBI/IDF criteria. Anthropometric and laboratory parameters, food-group consumption frequency, and physical activity were assessed. Associations with MetS were examined using separate multivariable logistic regression models. Results: MetS was identified in 69 participants (26.6%; 95% CI: 21.6–32.3%). In the total sample, elevated blood pressure (54.4%) and abdominal obesity (54.1%) were most prevalent; among participants with MetS, abdominal obesity (98.6%) and elevated blood pressure (91.3%) predominated. In age- and sex-adjusted models, HOMA-IR ≥ 2.5 and elevated ALT activity were associated with MetS (aOR = 14.99; 95% CI: 6.75–33.32 and aOR = 4.25; 95% CI: 1.61–11.24, respectively). Exploratory comparisons indicated higher self-reported vigorous physical activity among participants without MetS. In exploratory dietary models adjusted for age, sex, smoking, and total physical activity, more frequent consumption of nuts and seeds and natural dairy products was associated with lower odds of MetS, whereas alcoholic-beverage consumption was associated with higher odds. Conclusions: MetS affected more than one-quarter of the soldiers despite their current medical fitness for service. The strongest laboratory associations involved HOMA-IR and ALT. Dietary associations were exploratory, were not adjusted for military branch or multiple comparisons, and remain subject to residual confounding and the limitations of self-reported lifestyle assessment. They do not establish independent protective or adverse effects of individual food groups. The cross-sectional design precludes causal inference. These results support systematic cardiometabolic risk assessment in military personnel.