Especially if weight-related diseases run in your family, you’ve probably wondered, “What are some health risks of obesity?”
Some side effects of excessive weight gain, such as needing a mobility aid to move around, may seem minor. However, the long-term effects of obesity are linked to major health complications, such as a heart attack.
Ahead, find more critical information on the health risks of obesity as we address common questions like “How does obesity affect the body?”
How Does Obesity Affect the Body?
Overweight and obesity refer to terms defined in the body mass index (BMI). This tool is not intended to be used independently, but rather to help track trends in body weight over time. Using the BMI, a score of 30 or higher is considered to be obese.
A Quick Note On BMI and Obesity
BMI is not the best measurement of health and can be flawed, just like any other medical measurement system. For example, an athlete in great shape may measure as “obese” according to the BMI scale. But BMI is simply a formula and can fail to take body composition into account.
Work with your doctor and dietitian to better understand your BMI. As mentioned above, BMI is best used in collaboration with other indicators, such as risk factors. Weight loss interventions aren’t a “one-size-fits-all”, so it’s important to consult with your health team to find strategies and solutions that work for you.
Effects Beyond Body Fat
Obesity is more than excess body fat and weight gain often impacts most of your body’s organs. For example, excess weight can put wear and tear on your bones and joints over time.
If efforts aren’t taken to maintain a healthy weight, one of the body’s most important muscles and organs, the heart, can wear down as well. Obesity increases the risk for coronary heart disease as well as other risk factors, like high LDL or “bad” cholesterol.
10 Health Risks of Obesity
Lack of physical activity contributes to weight gain, but so do bad diet, sleep, and stress management habits. To further motivate yourself to maintain a healthy weight, it’s crucial to understand the risks linked with obesity.
1. Type 2 Diabetes
One condition closely associated with body weight is type 2 diabetes. High blood sugar over time can lead to a diabetes diagnosis. A recent study found that, regardless of genetic predisposition, obesity and lifestyle habits (like poor diet and lack of exercise) were associated with a higher risk for type 2 diabetes.
The good news? It’s never too late to implement positive lifestyle changes to help balance blood sugar or manage your diabetes.
2. High Blood Pressure
A rise in BMI is also linked to a rise in blood pressure (hypertension). However, when obesity occurs, blood pressure can increase due to the following factors:
• Alterations in the structure of blood vessels and other organs
• Impaired hormone signals
• Nervous system dysfunction
Essentially, excess body fat increases the demand a pressure put upon the body. Even a 3% reduction in body weight (as little as about 10 pounds) can significantly lower blood pressure.
If left untreated, obesity can even lead to a condition called resistant hypertension, in which case blood pressure is uncontrolled. The risks of developing heart disease also rise when hypertension enters the picture.
3. Heart Disease
Another diagnosis associated directly with body weight is cardiovascular (heart) disease. Heart disease can be linked with other obesity risks as well, such as:
• High blood pressure
• High blood sugar
• High LDL or “bad” cholesterol
• High triglycerides
The risks listed above should be treated as red flags. When ignored, symptoms can lead to more serious consequences, like coronary artery disease (CAD) and cardiovascular death.
4. Heart Attack and/or Stroke
Speaking of serious consequences, both heart attacks and strokes are associated with obesity. Obesity can cause changes in heart function and structure. CAD is the most common cause of heart attack, and obesity is also linked to increasing the risk of CAD.
Blockages and blood clots in the body can also result in increased stroke risk. Obesity is estimated to raise the risk of stroke by almost 65%. Strokes can cause serious damage and even death, so this association is not to be taken lightly.
5. Mental Illness
Another sneaky symptom related to obesity is the decline in mental health. Since some hormones that regulate mood are impacted by gut health, poor gut health can be linked to mental illnesses like anxiety and depression.
In fact, studies confirm that the gut microbiome, or the intestinal environment, of people who qualify as obese was less diverse. Since a certain balance of “good” and “bad” bacteria is needed for proper gut health, this imbalance can have implications on the body and mind.
Beyond the link between gut health and mental health, those with obesity face higher rates of depression. Interestingly, researchers are still struggling to find out whether obesity causes depression or if depression causes obesity. Many experts believe that the two conditions play into one another, with obesity worsening depression and depression worsening obesity.
Additionally, complicated conditions like diabetes (which obesity also raises the risk of) are also related to higher rates of depression. Although many people acknowledge the bodily effects of obesity, the effects on the mind are worth considering as well.
6. Sleep Apnea
Another area of the body that can be affected by obesity is the lungs. Gaining weight around organs and muscles essential to breathing, such as the diaphragm, can seriously impact your ability to breathe.
While diseases like asthma may develop alongside obesity, a common complaint associated with obesity is sleep apnea. During this disorder, breathing stops and restarts while you sleep. Understandably, this order can be dangerous and deprive your body of getting enough air. It’s estimated that 50-75% of individuals with obstructive sleep apnea are also obese.
7. Liver Disease
The liver is a key organ in the body, breaking down nutrients and metabolizing medicine. In obese individuals, the risk of liver diseases like nonalcoholic fatty liver disease (NAFLD) increases. In NAFLD, as the name suggests, there is too much fat being stored in the liver cells.
NAFLD has become more common in Western nations, where obesity is also on the rise. Fatty livers can cause serious inflammation and eventually scarring that can cause injury to the liver.
Many risk factors and links exist between obesity and NAFLD, including:
• High blood sugar
• High cholesterol
• High triglycerides
• Insulin resistance
• Sleep apnea
• Type 2 diabetes
Fortunately, maintaining a healthy diet and weight can prevent the risks associated with both NAFLD and obesity.
8. Gallbladder Disease
The formation of gallstones has long been linked with obesity. Gallstones are created when an imbalance of bile exists inside the gallbladder. In obesity, higher levels of cholesterol and bile can increase the risk of gallstones.
Unsafe, rapid weight loss can prevent the gallbladder from functioning or emptying properly. Weight loss surgeries can also cause rapid weight loss and increase the risk of gallstones. In other words, sustainable weight loss habits (such as balanced meals and mindful movements) are thought to have better benefits for your gallbladder long-term.
As mentioned above, obesity puts pressure on bones and joints in the body. In an effort to support the added weight, wear and tear on bones and joints can develop. This can cause bones to break down and joints to be increasingly inflamed, ultimately leading to a chronic disability called osteoarthritis (OA).
When it comes to OA, obesity is considered both an influential and modifiable risk factor. In other words, since adipose (fat) tissue plays a crucial role in inflammation, reducing your risk of obesity can also reduce the risk of developing OA.
10. Certain Types of Cancer
While not entirely clear, there is a connection between certain types of cancer and obesity. Links between cancers of the pancreas (where insulin is produced), gallbladder, and kidneys make the most sense. Other types of cancer, like breast cancer, are still being studied to see how obesity affects disease progression.
One reason that cancer may be linked with obesity is that type 2 diabetes is also a cancer risk factor. Since obesity is a risk factor for diabetes, both conditions can increase cancer risk.
Another reason for this link is that fat tissue can cause chronic inflammation and chronic inflammatory disease. Over time, this stress on the body can lead to cell and DNA damage. Ultimately, this breakdown of body tissue can make the body more susceptible to certain cancers.
The Bottom Line on the Effects of Obesity
Losing weight can seem overwhelming at first, but it is worth it to avoid the harmful effects of obesity. Being overweight or obese is a risk factor for many diseases, including ones that affect both the physical body and mind. Understanding the risks of obesity today can help you avoid health risks in the future.
Edwards JM. How Obesity Can Increase Your Risk for Hypertension (and What You Can do About It). Healthline. Published April 2022.
Dieting & Gallstones. National Institute of Diabetes and Digestive and Kidney Diseases. Published November 2017.
Health Effects of Overweight & Obesity. CDC. Published September 2022.
Heart Attack Causes and Risk Factors. National Heart, Lung, and Blood Institute. Published March 2022.
Mayo Clinic Staff. Diabetes prevention: 5 tips for taking control. Mayo Clinic. Published June 2021.
Mayo Clinic Staff. Nonalcoholic fatty liver disease. Mayo Clinic. Published September 2021.
Obesity and Cancer. National Cancer Institute. Published April 2022.
Obesity Prevention Source. Harvard T.H.
Shabanzadeh DM. Incidence of gallstone disease and complications. Curr Opin Gastroenterol. 2018;34(2):81-89.
Tanaka M. Improving obesity in blood pressure. Hypertens Res. 2020;43(2):79-89.
Wang T, He C. Pro-inflammatory cytokines: The link between obesity and osteoarthritis. Cytokine Growth Factor Rev. 2018;44:38-50.