Body Composition and Lifestyle Characteristics of Blue- and White-Collar Workers: A Cross-Sectional Study

Background: Lifestyle plays a major role in preventing obesity and shaping overall health. Blue-collar and white-collar jobs differ in terms of lifestyle and level of physical activity (PA) during work. Aims: The aim of this study was to investigate the relationship between occupational factors (primarily type of work—blue-collar or white-collar, working hours, and night shift work) and body composition in adults aged over 40. Methods: A survey on occupation, hours worked per week, night shift work, education, age, sex, dietary habits and amount of PA based on the IPAQ-SF was conducted. Body composition was assessed using a bioelectrical impedance analysis device, with a focus on body fat percentage (BF%) and skeletal muscle mass (SMM%). The study was conducted between November 2023 and February 2025 in Konstancin-Jeziorna, Poland. Results: The study sample consisted of 203 adults undergoing rehabilitation (55.17% men, 39.41% blue-collar workers), aged 40–70 years (mean age: 53.4 ± 7.6). After adjustment for sex and age, significant differences in SMM% (F = 2.38; p = 0.018) and BF% (F = 2.71; p = 0.008) were observed among industries, with the mechanical manufacturing and transport workers group showing higher SMM% and lower BF%. than the services and sales group. No significant differences were found in body composition parameters between blue-collar and white-collar workers after adjustment for sex and age. A higher declared PA was associated with a lower BF% (ρ = −0.1487; p = 0.04) and a higher SMM% (ρ = 0.1872; p = 0.009). Conclusions: This study highlights occupational differences between industries, with the mechanical manufacturing and transport workers group showing higher SMM% and lower BF% compared to the services and sales group. These findings suggest that differences in the organization and physical demands of work may be associated with differences in employees’ body composition.