Aim: There is a clinical perception that adults with more severe obesity have lower weight loss compared to people with lower grades of obesity. This study aimed to compare weight loss in people with clinically severe obesity (body mass index [BMI] >35kg/m2 and at least one significant obesity-related complication) following 12 months in a publicly funded multidisciplinary weight management program (WMP) across different BMI categories, and also compared the prevalence of Type 2 diabetes (T2D) in these BMI categories.
Methods: A retrospective review of all adult patients with clinically severe obesity who commenced a publicly funded WMP in Sydney between March 2018 and April 2024 and followed up at 12 months, comparing weight loss and T2D prevalence across BMI groups.
Results: Of 398 participants, 68% female, age 50.2±13.1 years, mean weight 149.6±34.8kg, BMI 53.1±10.1kg/m2, and 70% Caucasian, mean percentage body weight loss (%BWL) at 12 months was 5.4±7.3%. Mean %BWL within the groups was, respectively: 3.2±8.3% (BMI 35-39.9kg/m2, n=22); 5.7±7.1% (BMI 40-49.9kg/m2, n=147); 5.4±7.1% (BMI 50-59.9kg/m2, n=136); 5.5±6.7% (BMI 60-69.9 kg/m2, n=60) and 5.2 ±8.3 (BMI >70 kg/m2, n=33). No significant difference in mean %BWL was found between the BMI classes (p=0.67).
The prevalence of T2D across groups was 68.2% (BMI 35-39.9kg/m2, n=22), 53.7% (BMI 40-49.9kg/m2, n=147), 42.6% (BMI 50-59.9kg/m2, n=136), 33.3% (BMI 60-69.9kg/m2, n=60), and 36.4% (BMI >70kg/m2, n=33). There was a negative association between BMI group and T2D status with the proportion of T2D decreasing with increasing BMI group (p=0.01) although this was not adjusted for age, sex or race.
Conclusions: Participation in a multidisciplinary weight management program for twelve months facilitated modest weight loss across all BMI categories in people with severe obesity with no significant difference between the BMI categories despite clinical perceptions. Paradoxically the higher BMI groups seemed to have a lower prevalence of T2D.