Climate Change May Increase Obesity, Researchers Suggest


David Merron / Getty Images

Key Takeaways

  • As climate threats grow, people may become more sedentary, a recent commentary notes.
  • This change will likely drive up transportation using fossil fuels, worsening the climate crisis.
  • Both obesity and climate effects tend to harm low-income areas disproportionately, making these potential changes even more of a concern.

Climate change is widely considered a threat to human health in multiple ways, and now researchers are suggesting one more effect that could be problematic—increased obesity. Published in the journal Hormone and Metabolic Research, commentary from researchers at Fox Chase Cancer Center in Philadelphia state that greenhouse gas emissions from the burning of fossil fuels have increased exponentially for the last 70 years.

They suggest this usage could continue its upward trajectory as severe weather events lead to more sedentary behavior—and subsequent use of fossil-fuel-dependent transportation—among people who have obesity.

“When temperatures rise, people typically become less physically active and that’s associated not only with obesity prevalence but also with more use of gas-powered transportation,” according to study co-author Christian Koch, MD, PhD, FACP, MACE the director of the Fox Chase Cancer Center’s division of endocrinology.

That means it is a bidirectional relationship. As climate change worsens, obesity is likely to increase and when it does, it will negatively impact the environment even more.

Potential Cancer Uptick

As obesity rates increase, it’s highly likely that cancer prevalence will rise as well for cancers that are associated with obesity, Dr. Koch says. He notes that this includes a wide range of cancers including breast, endometrial, esophageal, colorectal, and liver cancers. Other cancers that may be associated with obesity include multiple myeloma and cancers of the thyroid, pancreas, kidney, and gallbladder.

Christian Koch, MD, PhD

With this commentary, we’re trying to raise awareness about how things interconnect. People need to know about these associations.

— Christian Koch, MD, PhD

Dr. Koch says there are a number of reasons that people might be at much higher risk for these conditions. A major factor is that obesity often involves higher insulin levels, which have been associated with cancer development. Also, he adds, fat tissue in women can produce estrogens that are connected with breast, ovarian, and endometrial cancers.

“With this commentary, we’re trying to raise awareness about how things interconnect,” says Dr. Koch. “People need to know about these associations.”

Disproportionate Effect

Although it wasn’t part of the recent commentary, both obesity rates and climate change have been previously determined to affect low-income areas disproportionately. That means a surge in issues like cancer could also hit this population harder than others.

Already, addressing obesity on its own in these neighborhoods is challenging, especially childhood obesity, according to Erica Kenney, ScD, MPH, an Assistant Professor of Public Health Nutrition at the Harvard T.H. Chan School of Public Health.

Erica Kenney, ScD, MPH

It’s like any chronic disease. Prevention is much easier than treatment.

— Erica Kenney, ScD, MPH

Dr. Kenney indicates that it is a difficult issue to address because there are so many aspects of a child’s environment that will influence what they eat and how active they can be. These two variables have the most influence when it comes to the development of obesity.

“Even with school-based programs, there’s limited effect because what happens when they go home," she says. "What if their neighborhood lacks a place to play? That means they sit inside and watch TV for hours.”

Research published in Health & Place found that “neighborhood disadvantage” in childhood is significantly associated with obesity in adulthood. And once obesity takes hold, Dr. Kenney says it can be very difficult to reverse.

“It’s like any chronic disease,” she says. “Prevention is much easier than treatment. In the case of childhood obesity, that’s true at the highest possible level.

Multi-Level Approach

To address all the risks that are interrelated—climate change, obesity, cancer, and other health issues—requires more recognition about the problem, says Dr. Koch. However, pulling on one thread here will likely affect the others in a positive way as well.

For instance, if community-based programs can keep people active and using less transportation, it would have a beneficial effect on cancer rates and greenhouse gases. Similarly, encouraging urban designers to add more bicycling and walking paths and incentivizing cities into promoting shared rides and bus travel could continue to bring risks down.

“We know there is a bidirectional relationship between climate change and obesity,” says Koch. “That means strategies that improve the health of each individual can also have an effect on the planet.”

What This Means For You

As the planet warms, people are likely to become more sedentary. Researchers suggest this change in activity levels could cause not just an increase in obesity, but also a surge in related health issues. It also could negatively impact the environment as well as the use of cars and other types of transportation increase. If you would like to make changes to your activity levels, talk to a healthcare provider or a certified personal trainer for advice.


4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Koch CA, Sharda P, Patel J, Gubbi S, Bansal R, Bartel MJ. Climate change and obesity. Horm Metab Res. 2021 Sep;53(9):575-587. doi:10.1055/a-1533-2861

  2. Kim TJ, von dem Knesebeck O. Income and obesity: what is the direction of the relationship? A systematic review and meta-analysisBMJ Open. 2018;8(1):e019862. doi:10.1136/bmjopen-2017-019862

  3. Levy BS, Patz JA. Climate change, human rights, and social justiceAnn Glob Health. 2015;81(3):310-322. doi:10.1016/j.aogh.2015.08.008

  4. Alvarado SE. The indelible weight of place: Childhood neighborhood disadvantage, timing of exposure, and obesity across adulthoodHealth Place. 2019;58:102159. doi:10.1016/j.healthplace.2019.102159

By Elizabeth Millard
Elizabeth Millard is a freelance journalist specializing in health, wellness, fitness, and nutrition.