Quick Links
About MyObesityTeam
Powered By
Obesity is a health condition defined by having more body weight or fat than what is considered healthy for your height. This condition may affect your life expectancy (the average number of years you’re expected to live). Being diagnosed with obesity can also increase the risk of developing serious health problems, such as heart disease, diabetes, and certain types of cancer.
As rates of obesity around the world have increased, researchers have been studying the effect of obesity on life expectancy. Studies have found that obesity may shorten life expectancy as much as or more than smoking cigarettes.
It’s important to remember that your weight isn’t a direct indication of how healthy you are. However, having a higher body weight or being diagnosed with obesity can increase the risk of health conditions that may affect life expectancy. In this article, we’ll discuss what the research says about life expectancy with obesity and why obesity can shorten how long you’re expected to live.
Several studies have found that obesity can affect life expectancy.
A 2014 study reviewed the results of 20 other studies to compare the cause of death in people with class 3 obesity — body mass index (BMI) greater than 40 — and people with a BMI of 18.5 to 24.9. Researchers found people with class 3 obesity lived about 6.5 to 13.7 years less than those with a lower BMI.
How long people live may differ based on obesity class. People with class 2 obesity (BMI of 35 to 39.9) and class 3 obesity have a higher risk of dying compared to people with a higher body weight or class 1 obesity (BMI of 30 to 34.9). A 2016 study found that people with a higher body weight or class 1 obesity didn’t have an increased risk of death.
Obesity at a younger age may result in a bigger decrease in life expectancy. A 2018 study from Australia found that younger adults aged 20 to 29 with obesity had the highest number of years of life expectancy lost. Based on these study results from the International Journal of Obesity, men aged 20 to 29 with obesity may have their life expectancy shortened by 5.6 to 7.6 years, while women with obesity of the same age may lose 8.1 to 10.3 years.
Obesity is a risk factor for several other medical conditions that can affect your health and how long you live. It’s also linked to several comorbidities — other health conditions that occur at the same time. For example, having heart disease, stroke, and diabetes together may shorten your life expectancy by about 15 years. With two of these conditions, life expectancy might be reduced by 12 years.
Below are several comorbidities that are more likely to affect people with obesity.
Heart disease is the No. 1 cause of death in the United States and many other parts of the world. Heart disease (also known as cardiovascular disease) is a health condition that affects blood flow to your heart. If you have decreased blood flow to your heart, it can cause a heart attack. A heart attack can decrease your life expectancy by more than 16 years.
Obesity — especially abdominal obesity (excess fat around your waist) — is associated with metabolic syndrome. Metabolic syndrome is a group of health conditions associated with an increased risk of heart disease, stroke, and diabetes.
Obesity can increase your risk of heart disease because it also increases your risk of other heart disease risk factors, such as hypertension (high blood pressure). About 58 percent of people diagnosed with obesity have high blood pressure. Other risk factors for heart disease associated with obesity include:
Cancer develops when some cells in your body begin to grow and divide out of control. Life expectancy with cancer differs based on the type and stage of cancer.
Obesity is linked to an increased risk of several different types of cancer, including:
Some studies have found people with excess body fat have an increased risk of cancer, but it’s unclear how obesity increases the risk. Researchers think that excess fat around your organs can cause inflammation. Over time, inflammation from excess fat may damage the cells of your body, increasing your risk for cancer. Esophageal cancer can be caused indirectly by acid reflux, which is more severe in people with obesity.
Diabetes develops when your blood sugar is too high. People with obesity have an increased risk of developing type 2 diabetes. This type of diabetes happens when your body doesn’t use insulin properly. Insulin is the hormone responsible for helping the cells in your body use sugar to make energy. When your body can’t use insulin how it should, your blood sugar levels increase. This can damage several parts of your body. Diabetes is linked to some health conditions that can lower your life expectancy, including metabolic syndrome, heart disease, and stroke.
Diabetes is common in people with obesity. About 23 percent of people with obesity also have diabetes. On average, people with type 2 diabetes at age 50 have a life expectancy that’s six years shorter compared to those without it.
Obesity can increase your risk of kidney disease by directly affecting your kidneys and by increasing your risk of other conditions linked to kidney disease. Obesity can put stress on your kidneys by causing inflammation and making them work harder. Other health conditions, like diabetes, heart disease, and high blood pressure, can also damage your kidneys.
The life expectancy for someone with kidney disease depends on how serious the condition is and the age at which it begins. Talk to your healthcare team about your risk of kidney disease based on your comorbidities.
Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are liver diseases associated with obesity. MASLD and MASH cause a buildup of fat in the liver, which can eventually lead to liver failure. Additionally, liver disease increases your risk of liver cancer, heart disease, and stroke.
About 75 percent of people with a higher body weight, and 90 percent of people with class 3 obesity also have MASLD. It’s estimated that from 30 percent to 60 percent of people with type 2 diabetes have MASLD.
If liver disease progresses to cirrhosis (permanent liver scarring), life expectancy is between seven and 15 years.
Some studies have found that people with obesity may have better outcomes with some health conditions compared to people without obesity. This is known as the obesity paradox.
Although obesity is associated with an increased risk of heart disease and cancer, some research has found people with obesity may be less likely to die from these conditions. The reason for this is unclear but may be related to protective fat deposits.
However, recent research from the Obesity Medicine Association questions the obesity paradox. For example, BMI — the most common measure of excess fat — may not be accurate at predicting outcomes in people with heart disease. Additionally, conditions such as cancer and heart disease may cause weight loss. This finding may lead to studies reporting a lower weight when someone is diagnosed with these conditions.
Your healthcare team can help you understand how your comorbidities may affect your health outcomes.
Research has found that managing your comorbidities can increase your life expectancy. For example, a 2023 study found that people with good heart health have a life expectancy of almost nine years longer than people with poor heart health.
Making small changes can go a long way in increasing your life expectancy. Weight loss of just 5 percent to 10 percent of your body weight can make a big difference in your health risks. Talk to your healthcare team about obesity treatment options, such as obesity surgery.
Meeting treatment goals related to your health conditions can also help increase your life expectancy. Research has found that if you meet your treatment goals for type 2 diabetes, you can extend your life expectancy by as much as 10 years. Your healthcare team can help you understand your treatment goals and how best to achieve them.
To reduce your risk of heart disease, cancer, and other comorbidities associated with obesity, doctors recommend the following:
On MyObesityTeam, the social network and online support group for people with obesity and their loved ones, more than 56,000 members come together to share experiences, seek advice, and offer support.
Have you been diagnosed with obesity? What steps have you taken to increase your life expectancy? Share your comments below, or start a conversation by posting on your Activities page.
Flaviu Titus Patrascanu, M.D.
is a physician specializing in endocrinology and diabetes, nutritional, and metabolic disorders.
Learn more about him here.
Amanda Jacot, Pharm.D
earned a Bachelor of Science in biology from the University of Texas at Austin in 2009 and a Doctor of Pharmacy from the University of Texas College of Pharmacy in 2014.
Learn more about her here.
Get updates directly to your inbox.
Become a member to get even more:
Your Privacy Choices
We'd love to hear from you! Please share your name and email to post and read comments.
You'll also get the latest articles directly to your inbox.