A major new study published in JAMA delivers a sobering message—but also an important opportunity for action. Researchers found that obesity among U.S. adults has more than doubled over the past 30 years and is projected to continue rising well into the future. For people living with cancer—and for cancer survivors—this trend matters deeply.
Why obesity matters in cancer care
Obesity is not just a number on a scale. It is closely linked to higher risks of developing several cancers, including breast, colorectal, endometrial, pancreatic, kidney, and liver cancers. For those already diagnosed with cancer, obesity is associated with:
- More treatment-related side effects
- Increased surgical and radiation complications
- Higher risk of cancer recurrence
- Reduced physical function and quality of life
- Greater risk of heart disease, diabetes, and other chronic illnesses
This new study estimates that over 42% of U.S. adults were living with obesity in 2022, and by 2035, nearly 1 in 2 adults may fall into this category if trends continue. These numbers help explain why cancer survivors increasingly face complex health challenges long after treatment ends.
Disparities that affect real people
The study also highlights important differences by age, sex, race, ethnicity, and geography. Obesity rates were highest among women—especially Black and Hispanic women—and were particularly concerning among younger adults. Earlier onset of obesity means the body is exposed longer to inflammation, hormonal changes, and metabolic stress, all of which can influence cancer risk and long-term survivorship.
For cancer survivors, this reinforces an essential truth: your health journey does not end when treatment ends. Survivorship is about restoring strength, function, confidence, and long-term well-being—no matter your age or background.
The good news: lifestyle change works
While these statistics may feel overwhelming, they also point toward solutions that are within reach. Decades of research show that regular physical activity and healthy lifestyle habits can:
- Improve treatment tolerance
- Reduce fatigue, anxiety, and depression
- Improve strength, balance, and daily function
- Help manage body weight and metabolic health
- Lower the risk of cancer recurrence and other chronic diseases
Exercise is not about perfection or extreme workouts. Even modest, consistent movement—tailored to your abilities and treatment status—can have powerful benefits.
Exercise is Medicine—for survivors
At CancerFitness.org, we believe exercise is a form of medicine for cancer survivors. Structured, safe physical activity programs—often called Exercise Oncology—are designed specifically for people before, during, and after cancer treatment. These programs focus on:
- Aerobic fitness (walking, cycling, swimming)
- Strength training to rebuild muscle
- Balance and flexibility to reduce fall risk
- Individualized progression based on energy, symptoms, and goals
Importantly, exercise can be adapted for everybody, at every stage of cancer care.
A call to action for survivors
This new obesity research is not meant to alarm—it is meant to empower. If you are living with cancer or navigating survivorship, now is the time to take an active role in your long-term health:
- Talk with your oncology team about safe physical activity
- Start small and build gradually
- Seek programs led by professionals trained in cancer exercise
- Focus on progress, not perfection
You are not alone on this journey. With the right guidance, movement can become a source of strength, control, and hope.
Your body has already endured a great deal. Exercise is one way to help it heal, recover, and thrive.
For practical guidance, survivor-friendly resources, and evidence-based programs, explore more at CancerFitness.org.
Reference: US State-Level Prevalence of Adult Obesity by Race and Ethnicity From 1990 to 2022 and Forecasted to 2035. Nicole K. DeCleene, BS; Ethan Kahn, MPH; Chun-Wei Yuan, PhD; et al. JAMA. doi:10.1001/jama.2025.26817 Published online January 28, 2026.
