Dangers of obesity

Obesity is a chronic disease that can pose major long-term health risks. Those risks include many other associated health conditions, known as comorbidities.

Without treatment, obesity and related conditions can have severe — even life-threatening — consequences. But with timely treatment, you may not only reduce your obesity but also some of its comorbidities.

“For a lot of patients, if we get control of the root cause and get control of the obesity, these other comorbidities are showing improvement and even resolution as people lose weight,” says Scot Currie, DO, director, bariatric surgery, UPMC Altoona.

Learn more about the risks of obesity and treatment options.

What Is Obesity?

Obesity is a common, chronic disease characterized by excess fat. If you’re heavier than is healthy for your height, you are overweight or obese. That’s according to the Centers for Disease Control and Prevention (CDC).

Your body mass index (BMI) can determine whether you are overweight or obese.

For adults, the CDC classifies BMIs between 25 and 30 as overweight and BMIs of 30 or higher as obese. A BMI of 40 or higher indicates severe obesity.

Dr. Currie says people often think of obesity as a behavioral disease related to diet and exercise — eating too much and exercising too little. But hormonal, metabolic, or molecular factors also can cause obesity.

“There’s that stigma that the person could have prevented it,” Dr. Currie says. “But in some cases, that’s not the truth.”

Obesity rates continue to climb in the U.S. According to the most recent National Health and Nutrition Examination Survey, released in 2021:

  • 19.7% of U.S. children and adolescents (2 to 19 years old) were obese.
  • 41.9% of U.S. adults (age 20 and over) were obese. Of these, 9.2% were severely obese.

Worldwide, the World Health Organization (WHO) says obesity has grown to “epidemic proportions.” The rise of obesity is a major concern because of the health issues it can cause.

Never Miss a Beat!

Get Healthy Tips Sent to Your Phone!

Message and data rates may apply. Text the word STOP to opt out and HELP for help. Click here to view the privacy and terms.

The Risks of Obesity

According to the WHO, more than 4 million people who are overweight or obese die each year worldwide from these conditions. This surprising death rate comes in large part because people who are obese are at risk of many other health conditions, known as comorbidities.

Health conditions related to obesity include:

  • Asthma.
  • Certain cancers.
  • Gallstones and gallbladder disease.
  • Heart disease.
  • High blood pressure.
  • High cholesterol.
  • Kidney disease.
  • Liver disease.
  • Mental health burdens, such as anxiety and depression.
  • Osteoarthritis.
  • Sleep apnea.
  • Stroke.
  • Type 2 diabetes.

Dr. Currie says many people aren’t aware of the link between obesity and these health conditions.

“A lot of people don’t look at obesity as the root cause,” he says. “[For] people who have, say, heart disease, there is definitely a genetic predisposition to heart disease with high cholesterol. But that’s compounded with people who have obesity.”

If you are overweight or obese, your risks grow with your BMI — the higher your BMI, the higher the risk. Also, the longer you go without treating obesity and related conditions, the greater the risk. For example, diabetes can have long-term effects like blindness, non-healing wounds, and limb amputation.

“Getting ahead of the game when it comes to your weight and getting it under control quickly will definitely decrease the chance of you developing a comorbidity or will allow the comorbidities that you already have developed to improve and get better quicker,” Dr. Currie says.

Treatment Options for Obesity

Treatment options for obesity include lifestyle changes (such as diet and exercise), medication, and weight loss surgery. For people with severe obesity, surgery is often the best option for lasting results. However, you must meet certain criteria to qualify for surgery.

Diet and exercise

Lifestyle changes are often the first treatment option for obesity. These include eating a healthier diet and getting more exercise.

But for those changes to last, you need to make a long-term commitment to that lifestyle, Dr. Currie says.

Calorie-restricted diets can put your body into “starvation mode” or “survival mode,” he adds. When this occurs, your body slows its metabolism and holds onto fat stores for energy.

While few people manage to lose weight and keep it off, most people regain some or all of the weight they lost. Some gain back even more.

“Unless they continue to stay on that diet and continue to restrict portions, make good food choices, and have an exercise program, then when they fall off the wagon and stop doing that, they will put all that weight back on plus more,” Dr. Currie says.


The U.S. Food and Drug Administration (FDA) has approved some medications that can help with weight loss. The medication “basically causes us to feel full rather quickly,” Dr. Currie says.

Similar to lifestyle adjustments, there also is a risk of regaining weight if you stop taking the medication, Dr. Currie says.

“When we come off the medication, we’re right back where we started,” he says. “We’ve lost that ability to feel full early, and we put that weight back on and some additional.”

Weight loss surgery

For people with severe obesity, weight loss surgery is one treatment option. But to qualify for surgery, you must meet certain criteria:

  • A BMI of 40 or higher.
  • A BMI of 35 or higher, along with a serious comorbidity (type 2 diabetes, heart disease, sleep apnea, or more).
  • A BMI of 30 or higher, along with type 2 diabetes that is difficult to control through medical treatments and lifestyle changes.

Weight loss surgery options include gastric sleeve and gastric bypass procedures.

  • For the gastric sleeve procedure, the surgeon removes part of the stomach, leaving a smaller “sleeve.” This sleeve makes you feel fuller sooner.
  • Gastric bypass also makes your stomach smaller. However, the surgeon also reroutes part of your intestines. This way, you don’t absorb all the calories you consume.

Depending on your individual case, you may prove a better candidate for one procedure than the other.

For people with severe obesity, surgery is often the best chance for long-term results, Dr. Currie says.

“About 90% of our patients after bariatric surgery will lose 50% of their excess weight and then keep it off,” he says. “For a lot of people, that’s at least 50 pounds or more that they’re losing and then going to keep off in the long term with their surgery.”

Surgery also can reduce — and potentially even eliminate — comorbidities, Dr. Currie adds. Studies show weight loss surgery can lower a person’s risk of death from any cause by over 40%, he says.

“If we add lifespan to people’s lives because we’ve taken away their diabetes or we’ve taken away their heart disease or their high blood pressure and they don’t have the stroke that they would have had otherwise, those kinds of things are important,” he says.

Weight loss surgery comes with significant lifestyle changes afterward, including a restricted diet. Following a healthy diet and exercising after surgery are important for long-term results.

“Surgery is just a tool to kind of help us with the weight loss,” Dr. Currie says. “It’s not going to do it by itself. Those lifestyle choices are still going to be important to make.”

How to Seek Treatment for Obesity

If you are overweight or obese and want to know if you’re a candidate for surgery or other treatments, talk to your doctor.

Dr. Currie says you can contact UPMC Bariatric Services to speak with someone about your treatment options. You can go over the criteria for surgery to find out about the procedures and learn if you’re a candidate. You also can visit the website of the American Society for Metabolic and Bariatric Surgery for more information.

The sooner you seek treatment for obesity, the better, Dr. Currie says. Treatment can help you address both your weight and related conditions.

“If we can get control of obesity early and either prevent the comorbidity from ever happening or have it corrected in the early stages of it, then we keep ourselves from going down that road of chronic disease,” Dr. Currie says.

Centers for Disease Control and Prevention, Adult Obesity Facts. Link

Centers for Disease Control and Prevention, Defining Adult Overweight and Obesity. Link

National Health Statistics Reports, National Health and Nutrition Examination Survey 2017–March 2020 Prepandemic Data Files Development of Files and Prevalence Estimates for Selected Health Outcomes. Link

World Health Organization, Obesity. Link

About UPMC

Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 800 doctors’ offices and outpatient centers, with locations throughout Pennsylvania, Maryland, New York, West Virginia, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. We are dedicated to providing Life Changing Medicine to our communities.