Rapid versus gradual weight loss for achieving clinically meaningful obesity treatment targets

touchENDOCRINOLOGY coverage of ECO 2026

Could you give us a brief overview of the health and economic burden of obesity-related complications, and the rationale for targeting anthropometric thresholds such as BMI ≤27 kg/m² and waist-to-height ratio ≤0.53?

Obesity is now one of the dominant global public health challenges, and WHO approximates that more than 1 billion people live with obesity worldwide. The health consequences of obesity are numerous and serious and are increasingly well documented. The most prominent non-communicable diseases (NCDs) associated with overweight and obesity are cardiovascular diseases, type 2 diabetes, chronic kidney disease, certain cancers and musculoskeletal disorders.

The rationale for targeting body mass index (BMI) ≤ 27 kg/m² and waist-to-height ratio (WHtR) ≤ 0.53 is based on the work by Busetto et. al. 2025, which aimed to identify anthropometric values that correspond to a low-10-year risk of major obesity-related complications, specifically atherosclerotic cardiovascular disease, type 2 diabetes, hypertension and osteoarthritis.¹ Their key finding was that absolute BMI and WHtR measures after weight loss were more strongly associated with 10 year risk for obesity-related diseases than percentage weight change. This challenges the traditional focus on “≥ 5–10% weight loss” and instead supports a treat to target approach based on achieving specific anthropometric thresholds, like HbA1c or blood pressure targets in other chronic diseases.

Could you describe the aims, design and eligibility criteria of this study, including the rationale for comparing rapid and gradual weight loss approaches, and summarize the primary and exploratory endpoints and their key findings at 1 year?

The study was a 52 week randomized controlled trial in adults with obesity (BMI ≥ 30 kg/m²), designed to compare rapid versus gradual weight loss programs. Its primary aim was to assess differences in 1 year percentage total body weight loss. The achievement of clinically meaningful adiposity targets (BMI ≤ 27 kg/m² and WHtR ≤ 0.53), was exploratory outcomes. The rationale for the study was to challenge prevailing assumptions about RWL, generate high-quality evidence, and determine which strategy more effectively helps patients reach anthropometric thresholds linked to reduced long-term risk of obesity-related complications.

The study met its primary endpoint, demonstrating significantly greater 1 year weight loss with rapid versus gradual weight loss (−14.4% versus −10.5%). Importantly, rapid weight loss also led to substantially higher attainment of clinically meaningful BMI and WHtR targets linked to reduced long-term complication risk. Clinicians should interpret these differences as both statistically and clinically significant, indicating that rapid weight loss, when delivered in a structured setting, not only produces greater weight loss but more effectively moves patients into lower-risk categories for obesity-related disease.

Rapid weight loss approaches are sometimes associated with concerns around sustainability and safety. What did this study show regarding the challenges of long-term weight management and maintaining clinically meaningful outcomes over 52 weeks?

This study showed that following a low energy, food-based diet leading to rapid weight loss, is both effective and sustainable over 52 weeks when delivered within a structured and supervised programme. Participants in the RWL group not only achieved greater initial weight loss but also maintained superior weight loss and higher rates of clinically meaningful BMI and WHtR targets at 1 year, with no evidence of increased weight regain. These findings challenge the prevailing concern that rapid weight loss is inherently unsustainable and support its use as a durable strategy for long-term obesity management.

What do these findings mean for clinical practice, and what do you see as the future place of structured, professionally supervised rapid weight loss programmes within the treatment paradigm for obesity?

Based on individual assessment and shared decision-making, these findings suggest that RWL- programmes could play an important role in the treatment paradigm; both as an effective initial intervention for patients with obesity, and perhaps particularly relevant for those needing substantial and timely risk reduction. Such programmes could be positioned ahead of—traditional gradual lifestyle interventions. Further, the exploratory study findings support a shift toward a treat-to-target model, similar to other chronic diseases by using BMI and WHtR thresholds as clinical targets. RWL programmes could also function as an accessible alternative where medications or surgery are not available or affordable and a bridge or adjunct, potentially preparing patients for or enhancing outcomes of medical therapies. Lastly, RWL programmes could represent a potential to reduce healthcare burden by helping more patients achieve clinically meaningful risk reduction and thereby contribute to lower incidence of obesity-related complications. This may have implications for reducing long-term healthcare costs and system strain.

Taken together, our findings suggest that structured, professionally supervised rapid weight loss programmes should be considered a safe, effective, and sustainable component of obesity treatment. They challenge long-standing assumptions about weight loss strategies and support a shift toward earlier, more intensive intervention and clear, risk-based treatment targets.

In the future, RWL programmes have the potential to play a central role in a more proactive and target-driven approach to obesity management, particularly as scalable, non-pharmacological treatment options.