Exploring The Interplay Between BMI, Subjective Body Image Perception, And Health Behaviors

Body Mass Index (BMI) is widely used to classify weight status and is linked to physical activity (PA) levels. However, BMI has limitations, as it only accounts for height and weight, ignoring critical psychological factors that impact health behaviors. Self-body image perception (SBIP), including negative body image perception (NBIP), plays a significant role. Negative body image can lead to chronic stress, emotional distress, and low self-esteem, creating barriers to PA participation, reducing motivation, and worsening management of metabolic risk factors associated with chronic diseases. PURPOSE: This study analyzed the impact of discrepancies between BMI and SBIP on metabolic risk factors, PA, sedentary behavior (SB), sleep time (ST), and stress levels. METHODS: Data from 8,634 participants in the 8th Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed. Participants were categorized into three groups: Accurate Perception (SBIP = BMI), Group B (SBIP < BMI), and Group C (SBIP > BMI). Chi-square tests, ANOVA, and multinomial logistic regression assessed the associations between SBIP-BMI discrepancies and health behaviors. RESULTS: Group B showed higher obesity and metabolic risks, including elevated fasting glucose (102.11 mg/dL) and triglycerides (161.74 mg/dL). Group C had better HDL cholesterol (59 mg/dL) and a lower risk of hyperlipidemia and hypertension. Moderate-to-vigorous PA was lowest in Group C (97.88 min/week), followed by Group A (133.18 min/week) and Group B (169.64 min/week). SBIP discrepancies had a stronger effect on PA and SB than BMI alone, with Group C being 1.30 times more likely not to meet PA guidelines. Stress levels were significantly higher in those with lower BMI or higher SBIP (OR = 1.93, p < 0.01). CONCLUSIONS: SBIP may have a stronger influence on health behaviors than BMI alone, particularly in shaping PA patterns. Supported by: This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea