Abstract： Objective:To analyze the current status of physical composition in medical workers and the evaluation effects of each indicator on nutritional status.Methods:It was a cross-sectional study. A total of 313 medical workers from one hospital in Beijing were recruited from May 21st to June 22nd in 2021 for body composition measurement. Variance analysis was used to compare the age and gender distribution differences in total body fat, fat-free body weight, body fat percentage, skeletal muscle, protein, water, mineral, and basal metabolic rate indicators among the medical workers. Protein content, body fat percentage, and body mass index (BMI) were used to evaluate the nutritional status of medical workers, and the evaluation effects were analyzed too.Results:Of the 313 medical workers included in this study, there were 221 females and 92 males. In females, total body fat, fat-free body weight, skeletal muscle mass, and basal metabolic rate were all positively correlated with age ( F=19.823, 6.745, 6.561, 6.707) (all P<0.001). There was no significant differences in body composition indicators among male participants of different age groups (all P>0.05). The total body fat in female medical workers was significantly higher than that in males (17.58 kg vs 17.08 kg). Total water, protein, minerals, fat-free body weight, skeletal muscle mass, and basal metabolic rate were all significantly lower in female medical workers when compared with those in males [30.40 kg vs 41.78 kg, 8.07 kg vs 11.26 kg, 2.96 kg vs 3.88 kg, 41.43 kg vs 56.92 kg, 22.37 kg vs 31.98 kg, 1 264.86 kcal (1 kcal=4.184 kJ) vs 1 599.39 kcal] (all P<0.05). Among the medical workers, 190 cases (60.7%) had normal protein levels, 103 cases (32.9%) had protein deficiencies, and 20 cases (6.3%) had protein levels exceeding the standard. Additionally, 110 cases (35.1%) had normal body fat ratios, 193 cases (61.6%) had excessive body fat ratios, and 10 cases (3.2%) had insufficient body fat ratios. Concerning body mass index (BMI), 198 cases (63.2%) had normal BMI. Among them, 145 cases (73.2%) had normal body fat ratios, 53 cases (26.7%) had excessive body fat ratios, 108 cases (54.5%) had normal protein levels, 89 cases (44.9%) had insufficient protein levels, and 1 case (0.5%) had excessive protein levels. Furthermore, 103 cases (32.9%) had excessive BMI, with 20 cases (19.4%) having normal body fat ratios indicating the muscle/bone strength type, and 83 cases (80.6%) having normal protein levels indicating the muscular type. Lastly, 12 cases (3.8%) had insufficient BMI, including 6 cases (50.0%) with normal body fat ratios. Conclusion:There are significant gender differences in body composition distribution among healthcare workers. In females, total body fat, lean body mass, skeletal muscle, and basal metabolic rate are all correlated with age. Evaluating individual nutrition status based solely on BMI would underestimate the obesity rate. Individuals with low or high protein/muscle content should not be assessed using BMI.