New research questions focus on percentage weight loss targets
New research presented at this year’s European Congress on Obesity (ECO 2025), suggests that weight loss programmes that set specific percentage weight loss goals are often falling short — and may not always reflect the most meaningful health outcomes for people living with obesity.
The international team behind the study, including Dr Sanjeev Sockalingam of Obesity Canada and the Centre for Addiction and Mental Health in Toronto, Canada, reviewed the evidence around percentage-based targets in obesity interventions. They argue that it may be time to move away from rigid weight-based outcomes and instead focus on improving obesity-related complications, quality of life and physical and social functioning.
The scoping review analysed data from 30 studies published between 1992 and 2024, drawing from databases including Cochrane, MEDLINE and EMBASE. The studies included both randomised controlled trials and non-randomised trials, all involving adults living with obesity. Most of the interventions targeted a weight loss of between 3 and 10 per cent, with a few aiming higher.
However, researchers found a frequent disconnect between the weight loss targets set and the results achieved. In some studies, only a third of participants managed to reach a 10 per cent weight loss goal, and a significant number of studies failed to report post-intervention outcomes such as BMI or weight change. The reasons for choosing specific targets also varied, ranging from disease-specific aims to general improvements in quality of life.
Notably, the commonly used 5 per cent weight loss target was originally derived from a small number of well-funded studies that linked this level of reduction to measurable health improvements. However, the new review highlights that these benefits may also be seen through interventions such as dietary changes, physical activity and lifestyle support — regardless of whether the individual achieves a particular weight loss target.
“Despite the prevalence of established weight loss targets, our review suggests these are often unattainable and unsustainable for most participants,” the authors conclude. “Obesity management interventions would benefit from shifting focus towards more comprehensive, patient-focused parameters, such as improvement of obesity-related complications, enhancing quality of life and overall physical and social functioning. This approach could provide more meaningful measures of success beyond mere weight reduction.”