What Is the Relationship Between Obesity and Inflammation?
Obesity and inflammation are closely linked and can create a harmful cycle that disrupts your body's systems, harms organs, and raises the risk of serious health problems.
"Accumulation of excess fat tissue in the body creates a state of chronic, low-grade inflammation," says Caroline Collins, MD, an internist and lifestyle medicine doctor. "This type of inflammation doesn't fight infection; it damages tissues over time and contributes to diseases like type 2 diabetes, heart disease, fatty liver disease, and some cancers."
With a better understanding of how obesity and inflammation are related, you can do things to improve your health. Research shows that making lifestyle changes – from eating a healthier diet to exercising more – can reduce inflammation.
GLP-1 receptor agonist medications – such as liraglutide (Saxenda, Victoza), semaglutide (Ozempic, Rybelsus, Wegovy), and tirzepatide (Mounjaro, Zepbound) – have also proven to reduce inflammation in fat tissue.
"They're amazing in that they help with weight loss, and they help people from being hungry all the time," says Randolph DiLorenzo, MD, the medical director of Northwell Syosset Hospital in Syosset, New York. "By doing so, it helps people start exercising more and change their lifestyle and their diet. This really is beneficial to the patient – both mentally and physically."
Does Obesity Cause Inflammation?
Obesity directly causes inflammation in fat tissue. At its core, obesity triggers changes in how your body processes energy. As fat cells grow larger, they release hormones and other chemicals that cause inflammation to spread throughout your body.
This inflammation, in turn, can interfere with how your body uses insulin, leading to insulin resistance and causing serious health problems.
"These changes turn fat tissue from anti-inflammatory to a pro-inflammatory one, which can spread inflammation throughout the body," says Collins, who is also an assistant professor at Emory University's School of Medicine. "Obesity leads to persistent activation of the immune system, creating a low-grade, chronic inflammatory state."
Does Inflammation Cause Weight Gain?
Inflammation can lead to weight gain by causing insulin resistance and impacting the hormones that control appetite and metabolism.
DiLorenzo says chronic inflammation "doesn't cause weight gain on its own" – it's "bi-directional. The inflammation doesn't cause the weight gain per se; they both cause each other."
"The inflammation promotes a biological environment that promotes the fat to be stored and the person's appetite to be increased," he says. "Then, the person has a reduced energy use – all of which makes it harder to maintain a healthy weight."
"It's a vicious circle," he says.
Collins adds that inflammation can contribute to weight gain "by interfering with hormones that regulate appetite and metabolism."
"For example, fat cells release leptin, a hormone that typically tells the body you are full," she says. "However, in obesity, the body becomes resistant to leptin, leading to increased appetite and overeating."
Adipose tissue inflammation
There are many ways that adipose tissue, or body fat, can cause inflammation.
When fat tissue expands, especially around your organs, it gets stressed and recruits immune cells. These cells release pro-inflammatory cytokines – proteins that send signals – causing chronic inflammation throughout your body.
Visceral body fat, the type that lies within your abdomen around your organs, tends to become more inflamed as a result.
"That's how you get all the consequences of the obesity-related inflammation: insulin resistance, metabolic syndrome, and other types of diseases," says DiLorenzo, who is also an assistant professor of medicine at Hofstra University.
How Is Obesity Related to Chronic Inflammation?
Obesity can trigger low-grade chronic inflammation, often called metaflammation. This type of inflammation isn't visible, like when you hurt your ankle and it swells.
But the consequences of chronic inflammation can be much more serious because of its impact throughout your body.
"As fat cells enlarge, they become stressed and release inflammatory molecules called adipokines and cytokines," Collins says. "These attract immune cells like dysfunctional macrophages into the fat tissue. This ongoing, chronic immune activation creates systemic inflammation that can affect many organs."
Can Inflammation Cause Other Health Conditions?
Inflammation can interfere with the body's ability to respond to insulin, leading to insulin resistance, a condition that disrupts how your body regulates blood sugar and fats.
When this happens, sugar and fat build up in your bloodstream. Over time, elevated levels of glucose and lipids can contribute to high blood pressure, bad cholesterol, and other metabolic changes.
Together, these issues form metabolic syndrome and increase your risk of health problems, including:
- Type 2 diabetes
- Diseases of your heart and blood vessels (cardiovascular disease)
- Fatty liver disease
- Kidney disease
- Gallstones
Obesity also increases your risk of 13 types of cancer, including pancreatic, breast, colorectal, uterine and ovarian cancers. Over time, it also may also increase your risk of Alzheimer's disease and dementia.
How to Reduce Inflammation in the Body
To reduce inflammation, you can follow a healthy diet and get regular exercise.
Research shows that one of the best things you can do is to eat a diet high in fruits, vegetables, whole grains, nuts, and lean protein. Experts also recommend limiting ultra-processed foods, sugary drinks, and cereals high in sugar.
"One of the worst things you can do is eat these highly processed packaged foods and fast foods," DiLorenzo says.
Collins adds that regular physical activity, adequate sleep, stress management, and avoiding smoking and alcohol can also reduce inflammation.
Medications like GLP-1 receptor agonists also reduce inflammation in fat tissue.
"Even a modest decrease in fat tissue can lower inflammatory markers," Collins says.
"I've had a tremendous number of obese patients with severe arthritis, with knee pain, back problems – as soon as they lose the weight, the diabetes either resolves or gets significantly decreased," DiLorenzo says. "Their cholesterol comes down. They just feel so much better because they're not carrying around all this extra weight."
Takeaways
Obesity and inflammation are deeply connected. Excess fat tissue creates chronic, low-grade inflammation, putting an obese person at risk of serious health issues.
Improving your diet and getting regular exercise can reduce inflammation and improve your health. Newer medications have also proven to be effective at reducing weight, thereby reducing inflammation.
Obesity and Inflammation FAQs
What is the No. 1 habit you should break if you have inflammation?
Researchers recommend making changes to your diet and exercising more to reduce inflammation throughout your body.
"I'm big on exercise and sleep," DiLorenzo says. "Exercise is phenomenal, for well-being, for mental health, for overall health. It's great for controlling weight gain – but really diet is key."
With those changes, he says, people will "feel dramatically different and dramatically better. They would say, 'Wow, I wish I knew about this before.' "
Collins agrees, saying, "Both exercise and nutrition are important when talking about reducing inflammation in the body. Nutrition has the largest impact on weight loss in general. Regular consumption of ultra-processed, high-sugar, and high-fat foods promotes obesity and increased inflammation. Replacing them with whole, minimally processed foods is one of the best steps to reduce inflammation.
"However, I cannot stress enough how important exercise, both aerobic and strength training, is to improve inflammation and overall health span."
Will losing weight always reduce inflammation?
Not necessarily. Collins says she tells patients to remember that "not all weight loss is good." For instance, if you are losing muscle instead of fat tissue, she says, "This is not beneficial."
It's best to lose visceral fat, the type that lies deep within your abdomen around your organs. "Visceral fat loss in particular tends to have the biggest impact on lowering inflammation," Collins says. And the good news is, you lose visceral fat the same way you lose fat in any other parts of your body – with good nutrition and exercise.
