Patients with Obesity: Baseline Body Composition, Follow-Up Retention, and Longitudinal Changes-A Single-Center...

Using real-world data from an obesity clinic, we aimed primarily to define the body composition phenotype associated with increasing obesity severity and to quantify follow-up retention and clinically meaningful weight loss. As a secondary exploratory objective, we also examined how diabetes mellitus (DM) relates to these patterns beyond BMI.

Among 5350 screened adults in the Obesity Clinic database, 2879 eligible individuals were included in the baseline cross-sectional analyses, including a non-obese comparison subgroup with BMI < 30 kg/m². The longitudinal cohort comprised 730 patients with obesity who returned for regular follow-up and had repeat BIA measurements at least 6 months after baseline. Patients were classified according to BMI and glycemic status.

Increasing BMI was associated with higher glucose, HbA1c, uric acid, triglyceride, C-reactive protein, and leukocyte levels and with lower HDL cholesterol. Body composition deterioration was driven predominantly by disproportionate increases in visceral fat score, fat mass, and total fat-to-muscle ratio rather than by parallel gains in muscle compartments. As obesity severity increased, the proportion of patients with diabetes also increased. Only 29.3% of the baseline obesity cohort achieved regular 6-month follow-up, and 79.0% of those followed lost less than 5% of baseline body weight. In age- and sex-adjusted analyses, the most pronounced DM-related body composition differences were observed in the BMI 30-39.9 kg/m² group, particularly through higher waist-to-height ratio and total fat-to-muscle ratio.

This study shows that increasing obesity severity is accompanied by a more adverse metabolic profile and a body composition pattern characterized by greater adiposity. Within this framework, diabetes-related body composition differences were not homogeneous across BMI categories and appeared to be most evident in the BMI 30-39.9 kg/m² group. The weaker association observed in the BMI ≥ 40 kg/m² group may be related to the reduced discriminative value of waist-based measures in severe obesity, where fat accumulation may extend across multiple compartments. Given the low continuity of follow-up and the limited rates of clinically meaningful weight loss, these findings support a more refined phenotyping approach in obesity management that incorporates body composition and fat distribution in addition to BMI.