Complications of Obesity

“It’s not a willpower problem. The biology behind it involves genetics, hormones, the gut-brain axis, and the way the body regulates appetite and energy storage over time,” says Georgia-based Jessica Duncan, MD, a board-certified obesity medicine physician and the chief medical officer at Ivim Health. The complications of obesity can be wide-ranging and complex.

Cardiovascular Risks: Heart Disease, Stroke, and Hypertension

“BMI alone is an imperfect measure of health,” says Savita Srivastava, MD, a board-certified gastroenterologist in Virginia. “It misses an important group of individuals who look lean on the outside but carry dangerous visceral fat on the inside. Waist circumference measures visceral fat. It’s a better predictor of heart disease risk than BMI alone.”

Metabolic Health: Diabetes, Liver, and Gallbladder

“Insulin resistance tells the liver to dump more cholesterol into the bile,” says Dr. Srivastava. “When bile becomes supersaturated with cholesterol, it crystallizes to form gallstones.”

Physical Impacts: Joints and Respiratory Function

Carrying extra weight affects how a person moves, breathes, and sleeps by putting both physical and chemical stress on the body.

“I will often tell my patients that belly fat is an organ itself designed to increase chronic inflammation,” says Srivastava. “These very same inflammatory cytokines are known triggers for conditions like asthma and osteoarthritis.”

The Link Between Obesity and Mental Health

• Cognitive behavior therapy
• Dialectical behavior therapy
• Interpersonal psychotherapy
• Motivational interviewing

• diethylpropion (Tenuate)
• liraglutide (Saxenda)
• naltrexone/bupropion (Contrave)
• orforglipron (Foundayo)
• orlistat (Xenical)
• phendimetrazine (Bontril)
• phentermine (Adipex-P)
• phentermine/topiramate (Qsymia)
• semaglutide (Wegovy)
• setmelanotide (Imcivree)
• tirzepatide (Zepbound)

Cancer Risk and Obesity

• Adenocarcinoma of the esophagus
• Breast (postmenopausal)
• Colon and rectum
• Gallbladder
• Kidney
• Liver
• Meningioma (a type of brain cancer)
• Multiple myeloma
• Ovary
• Pancreas
• Thyroid
• Upper stomach
• Uterus

Insights From Obesity Specialists

“The gut produces hormones like ghrelin, GLP-1, and PYY that tell the brain when to eat and when to stop,” says Dr. Duncan. In people with obesity, these signals are often dysregulated. The hunger hormone, ghrelin, stays elevated while fullness signals become blunted.

“It’s one contributor to what my patients describe as 'food noise,' a constant background hum of thinking about food, planning the next meal, or fighting cravings that are not about hunger at all,” she says. “It would be pretty tough to out-discipline a hormone.”

The medical community is also shifting how it approaches treatment.

“The biggest shift is the move away from treating obesity primarily as a weight problem and toward treating it as a chronic, relapsing disease with the end goal of preventing organ damage, not just hitting a number on a scale,” says Toronto-based Fady Hannah-Shmouni, MD, an endocrinologist and geneticist, and the medical director at Eli Health.

People with obesity don’t need to lose drastic amounts of weight to see real health benefits. “Overall, a 5 to 10 percent decrease is clinically meaningful and, importantly, achievable and sustainable for most of the population,” says Dr. Hannah-Shmouni. He explains that losing 5 percent of one’s total body weight can reduce strain on the heart, lower blood pressure, and improve cholesterol levels. Some people can even reverse conditions like prediabetes and mild diabetes with this moderate weight loss.

The Takeaway

• Obesity significantly increases the risk of life-threatening cardiovascular and metabolic issues, including hypertension, stroke, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease.
• Excess weight places both physical and chemical stress on the body, leading to joint degradation, respiratory issues like sleep apnea, and an increased risk of 13 types of cancer.
• There is a strong bidirectional link between obesity and mental health disorders as well.
• Obesity specialists emphasize that losing 5 to 10 percent of one’s total body weight can provide meaningful health benefits and help reverse certain complications of obesity.