Imagine being asked what success in obesity treatment would look like for you.
Maybe it’s having enough energy to get through the day. Walking further without pain. Improving your blood pressure or blood sugar. Sleeping better. Feeling more comfortable doing the things you enjoy.
Now imagine being told that success will actually be judged by one thing: the percentage of body weight you lose.
That disconnect has become an important question in obesity research.
Our earlier research looked closely at how percent weight loss became a common measure of success in obesity treatment and research. The conclusion was not that percent weight loss has no role in care, but that percent weight loss alone cannot tell us everything we need to know about whether treatment is improving someone’s health.
So the next question was a practical one:
If we want a broader definition of success, what should be in it?
A newly published study involving Obesity Canada and an international group of people living with obesity, clinicians, researchers, and organizational representatives begins to answer that question.
Moving from measuring percent weight loss to what people value
Our previous research showed that widely used percent weight loss targets often trace back to the same relatively small body of evidence. If also found that even in supported research settings, the proportion of people reaching those targets varied significantly.
That raised a larger issue: obesity is a complex chronic disease, yet treatment success is often judged by a single outcome.
That can leave important changes outside of the frame.
A person may experience improvements in an obesity-related health condition. They may be able to move more easily, feel better mentally, participate more fully in daily life or experience a better overall quality of life. Those changes can be meaningful even when the number on the scale doesn’t meet a specific target.
The new study shifts the conversation from identifying that problem to beginning to build something better.
What should count as success in obesity treatment?
Researchers brought together 18 people with different relationships to obesity care for an international workshop in Toronto, Canada, including people with lived experience, clinicians, researchers, and representatives from obesity organizations. Rather than asking one group to define success for everyone else, the process put different forms of knowledge around the same table.
Participants used a prioritization exercise called MoSCoW. Despite the name, the idea is straightforward: sort potential elements into what a future obesity management framework must have, should have, could have, and won’t have.
The conversation resulted in 15 themes to inform a future obesity management framework, including health gains, physical function, mental health, quality of life and patient-reported outcomes alongside weight.
What must be there
Participants said a future approach must recognize the different pillars of evidence-based obesity care, including behavioural support, medications, and surgery where appropriate.
They also prioritized valid ways to measure obesity-related health complications and patient-reported outcomes: changes in health and quality of life described by the person receiving care.
Another “must”: healthcare professionals need the knowledge and sensitivity to provide obesity care without reinforcing weight bias and stigma.
What should be there
Mental health and physical function emerged as important parts of the picture.
So did personalized measures of success.
That distinction is important. Two people receiving obesity treatment may have very different health concerns, priorities, or reasons for seeking care. A meaningful goal for one person may have little relevance to another.
A better approach needs room for both evidence and individualized goals.
What could strengthen care
Participants also identified opportunities such as ongoing education, team-based care and stronger connections between obesity care and health policy.
These ideas recognize that treatment doesn’t happen in isolation. Whether someone can access appropriate care, continue treatment and receive long-term support is also shaped by the systems around them.
The group was also clear about what should be left behind
Sometimes defining progress means deciding what no longer belongs.
The workshop also helped clarify approaches that participants felt should not define treatment success or guide a future framework.
These included:
- stigmatizing and judgmental language
- appearance alone as a measure of success
- short-term “quick-fix” approaches to a chronic disease
- targets applied without considering the individual person, their health, and their circumstances
Altogether, those choices say something important about the direction obesity care can take.
The goal isn’t simply to replace one universal number with a longer universal checklist.
It’s to create a way of understanding progress through a combination of clinical evidence, meaningful health outcomes, and what the person receiving care actually wants to improve.
Shared decision-making can help define treatment success
One idea appeared across many of the workshop’s priorities: shared decision-making.
That means a healthcare professional and a person living with obesity can talk about what improved health would actually look like, identify meaningful goals together and decide how progress would be followed over time.
Weight may still be one measure when it is clinically relevant.
But it could sit alongside changes in metabolic health, obesity-related complications, physical function, mental health, quality of life and other outcomes that reflect the person’s priorities.
That is much closer to how we think about managing other chronic diseases: not simply asking whether one number moved enough, but whether treatment is helping a person achieve better health.
The obesity management framework is still to come
The 15 themes identified through this workshop are a foundation for the next stage of the work. They will help inform the development of a more comprehensive obesity management framework that can bring together clinical evidence, patient priorities, and considerations for how care is delivered.
But the direction is becoming clearer.
This study begins to show what a broader picture of success in obesity care can include. Because better obesity care isn’t simply about finding another number to aim for.
It’s about being clearer about the goal in the first place: better health, defined with the person receiving care rather than for them.
Read the research
Rethinking Obesity Management Targets: Findings from an International MoSCoW Prioritization Workshop
Obesity Pillars, 2026
Missing the Target: A Scoping Review of the Use of Percent Weight Loss for Obesity Management
Obesity Reviews, 2025
Read our impact story: Rethinking percent weight loss as the success measure in obesity treatment
