PHILADELPHIA (October 12, 2021)—When people think of global warming and climate change, they tend to think of melting glaciers, rising sea levels, and drought. They do not, however, generally think of obesity and other potential health effects.
That relationship was explored in a recent review article authored by Christian Koch, MD, PhD, FACP, MACE, director of the Section of Endocrinology, and other colleagues at Fox Chase Cancer Center.
“This article is about raising awareness about how things interconnect; the average person needs to be aware of how these factors affect each other,” Koch said.
In their review, the researchers noted that there is a clear and complex relationship between obesity and global warming. With increased temperatures due to global warming, people become less physically active and less able to burn fat, all the while producing a higher carbon footprint.
In addition, those who are overweight or obese have a higher cancer risk than those of average weight, the researchers wrote: “Obesity is associated with risk of various malignancies, including breast and endometrial cancers, cancer of the esophagus, gastric cardia, colon, rectum, liver, gallbladder, pancreas, kidney, thyroid gland, and multiple myeloma.”
There are a variety of reasons for this increased risk, the authors note. One is the increase in insulin levels in obese people, which can lead to a higher risk for colon, kidney, prostate, and endometrial cancer. In women, fat tissue can generate estrogens that can promote endometrial, breast, and ovarian cancer. Elevated cancer risk is a reality for all individuals with a body mass index (BMI) above 25; a healthy BMI is between an 18.5 and 24.9.
The urbanization of land, use of motorized vehicles, and the high rates of consumption of animal products have all contributed to increasing rates of greenhouse gases and obesity globally, the authors write. Further exacerbating the problem is the elevated rate at which obese people consume energy, thus raising atmospheric temperature and leading to an increase in weight gain.
When atmospheric temperature rises, the ability of people to perform thermogenesis—the rate at which the human body burns off energy in different climates—is affected. In adaptive thermogenesis, the body’s resting metabolic rate is slowed down, so less energy is expended than would have normally been the case.
This process results in a cycle in which it becomes easier to gain weight, which then leads to more greenhouse gas emissions from using automobile and air transportation due to greater body weight and feeling less energetic and becoming less physically active.
“What we need to go back to is ‘less-is-more’ to address the problem,” said Koch. “It is better to have an excellent quality product that would cost more but is healthier rather than something that is lower quality, cheaper, and less healthy. We need to look at the whole picture and how we can make this world better.”
But it’s not only the quality of things such as food that is key, but how that food is combined. For example, the researchers noted, diets lower in meat such as a Mediterranean diet “have been estimated to reduce greenhouse gas emissions by 72%, land use by 58%, and energy consumption by 52%.”
The article, “Climate Change and Obesity,” was published in Hormone and Metabolic Research, and Koch said it has been one of the journal’s most-read articles since it was posted two months ago.