Health Risks of Being Overweight
What kinds of health problems are linked to overweight and obesity?
Excess weight may increase the risk for many health problems, including
- type 2 diabetes
- high blood pressure
- heart disease and strokes
- certain types of cancer
- sleep apnea
- fatty liver disease
- kidney disease
- pregnancy problems, such as high blood sugar during pregnancy, high blood pressure, and increased risk for cesarean delivery (C-section)
Body Mass Index
The BMI is one way to tell whether you are at a normal weight, are overweight, or have obesity. It measures your weight in relation to your height and provides a score to help place you in a category:
- normal weight: BMI of 18.5 to 24.9
- overweight: BMI of 25 to 29.9
- obesity: BMI of 30 or higher
Another important number to know is your waist size in inches. Having too much fat around your waist may increase health risks even more than having fat in other parts of your body. Women with a waist size of more than 35 inches and men with a waist size of more than 40 inches may have higher chances of developing diseases related to obesity.
Know your health numbers
Below are some numbers to aim for.1,2
|Waist Size||Men: less than 40 in.
Women: less than 35 in.
|Blood Pressure||120/80 mm Hg or less|
|LDL (bad cholesterol)||Less than 100 mg/dl|
|HDL (good cholesterol)||Men: more than 40 mg/dl
Women: more than 50 mg/dl
|Triglycerides||Less than 150 mg/dl|
|Blood sugar (fasting)||Less than 100 mg/dl|
Type 2 Diabetes
What is type 2 diabetes?
Type 2 diabetes is a disease in which blood sugar levels are above normal. High blood sugar is a major cause of heart disease, kidney disease, stroke, amputation, and blindness. In 2009, diabetes was the seventh leading cause of death in the United States.
How is type 2 diabetes linked to overweight?
More than 87% of adults with diabetes are overweight or obese.4 It isn't clear why people who are overweight are more likely to develop this disease. It may be that being overweight causes cells to change, making them resistant to the hormone insulin. Insulin carries sugar from blood to the cells, where it is used for energy. When a person is insulin resistant, blood sugar cannot be taken up by the cells, resulting in high blood sugar. In addition, the cells that produce insulin must work extra hard to try to keep blood sugar normal. This may cause these cells to gradually fail.
High Blood Pressure
What is high blood pressure?
Every time your heart beats, it pumps blood through your arteries to the rest of your body. Blood pressure is how hard your blood pushes against the walls of your arteries. High blood pressure (hypertension) usually has no symptoms, but it may cause serious problems, such as heart disease, stroke, and kidney failure.
A blood pressure of 120/80 mm Hg (often referred to as "120 over 80") is considered normal. If the top number (systolic blood pressure) is consistently 140 or higher or the bottom number (diastolic blood pressure) is 90 or higher, you are considered to have high blood pressure.
How is high blood pressure linked to overweight?
High blood pressure is linked to overweight and obesity in several ways. Having a large body size may increase blood pressure because your heart needs to pump harder to supply blood to all your cells. Excess fat may also damage your kidneys, which help regulate blood pressure.
What is heart disease?
Heart disease is a term used to describe several problems that may affect your heart. The most common type of problem happens when a blood vessel that carries blood to the heart becomes hard and narrow. This may keep the heart from getting all the blood it needs. Other problems may affect how well the heart pumps. If you have heart disease, you may suffer from a heart attack, heart failure, sudden cardiac death, angina (chest pain), or abnormal heart rhythm. Heart disease is the leading cause of death in the United States.3
How is heart disease linked to overweight?
People who are overweight or obese often have health problems that may increase the risk for heart disease. These health problems include high blood pressure, high cholesterol, and high blood sugar. In addition, excess weight may cause changes to your heart that make it work harder to send blood to all the cells in your body.
What is a stroke?
A stroke happens when the flow of blood to a part of your brain stops, causing brain cells to die. The most common type of stroke, called ischemic stroke, occurs when a blood clot blocks an artery that carries blood to the brain. Another type of stroke, called hemorrhagic stroke, happens when a blood vessel in the brain bursts.
How are strokes linked to overweight?
Overweight and obesity are known to increase blood pressure. High blood pressure is the leading cause of strokes. Excess weight also increases your chances of developing other problems linked to strokes, including high cholesterol, high blood sugar, and heart disease.
What is cancer?
Cancer occurs when cells in one part of the body, such as the colon, grow abnormally or out of control. The cancerous cells sometimes spread to other parts of the body, such as the liver. Cancer is the second leading cause of death in the United States.3
How is cancer linked to overweight?
Gaining weight as an adult increases the risk for several cancers, even if the weight gain doesn't result in overweight or obesity. It isn't known exactly how being overweight increases cancer risk. Fat cells may release hormones that affect cell growth, leading to cancer. Also, eating or physical activity habits that may lead to being overweight may also contribute to cancer risk.
What kinds of cancers are linked to overweight and obesity?
Being overweight increases the risk of developing certain cancers, including the following5:
- breast, after menopause
- colon and rectum
- endometrium (lining of the uterus)
What is sleep apnea?
Sleep apnea is a condition in which a person has one or more pauses in breathing during sleep. A person who has sleep apnea may suffer from daytime sleepiness, difficulty focusing, and even heart failure.
How is sleep apnea linked to overweight?
Obesity is the most important risk factor for sleep apnea. A person who is overweight may have more fat stored around his or her neck. This may make the airway smaller. A smaller airway can make breathing difficult or loud (because of snoring), or breathing may stop altogether for short periods of time. In addition, fat stored in the neck and throughout the body may produce substances that cause inflammation. Inflammation in the neck is a risk factor for sleep apnea.
What is osteoarthritis?
Osteoarthritis is a common health problem that causes pain and stiffness in your joints. Osteoarthritis is often related to aging or to an injury, and most often affects the joints of the hands, knees, hips, and lower back.
How is osteoarthritis linked to overweight?
Being overweight is one of the risk factors for osteoarthritis, along with joint injury, older age, and genetic factors. Extra weight may place extra pressure on joints and cartilage (the hard but slippery tissue that covers the ends of your bones at a joint), causing them to wear away. In addition, people with more body fat may have higher blood levels of substances that cause inflammation. Inflamed joints may raise the risk for osteoarthritis.
Fatty Liver Disease
What is fatty liver disease?
Fatty liver disease, also known as nonalcoholic steatohepatitis (NASH), occurs when fat builds up in the liver and causes injury. Fatty liver disease may lead to severe liver damage, cirrhosis (scar tissue), or even liver failure.
Fatty liver disease usually produces mild or no symptoms. It is like alcoholic liver disease, but it isn't caused by alcohol and can occur in people who drink little or no alcohol.
How is fatty liver disease linked to overweight?
The cause of fatty liver disease is still not known. The disease most often affects people who are middle-aged, overweight or obese, and/or diabetic. Fatty liver disease may also affect children.
What is kidney disease?
Your kidneys are two bean-shaped organs that filter blood, removing extra water and waste products, which become urine. Your kidneys also help control blood pressure so that your body can stay healthy.
Kidney disease means that the kidneys are damaged and can't filter blood like they should. This damage can cause wastes to build up in the body. It can also cause other problems that can harm your health.
How is kidney disease linked to overweight?
Obesity increases the risk of diabetes and high blood pressure, the most common causes of chronic kidney disease. Recent studies suggest that even in the absence of these risks, obesity itself may promote chronic kidney disease and quicken its progress.
What are pregnancy problems?
Overweight and obesity raise the risk of health problems for both mother and baby that may occur during pregnancy. Pregnant women who are overweight or obese may have an increased risk for
- developing gestational diabetes (high blood sugar during pregnancy)
- having preeclampsia (high blood pressure during pregnancy that can cause severe problems for both mother and baby if left untreated)
- needing a C-section and, as a result, taking longer to recover after giving birth
Babies of overweight or obese mothers are at an increased risk of being born too soon, being stillborn (dead in the womb after 20 weeks of pregnancy), and having neural tube defects (defects of the brain and spinal cord).
How are pregnancy problems linked to overweight?
Pregnant women who are overweight are more likely to develop insulin resistance, high blood sugar, and high blood pressure. Overweight also increases the risks associated with surgery and anesthesia, and severe obesity increases surgery time and blood loss.
Gaining too much weight during pregnancy can have long-term effects for both mother and child. These effects include that the mother will have overweight or obesity after the child is born. Another risk is that the baby may gain too much weight later as a child or as an adult.
If you are pregnant, check the sidebar for general guidelines about weight gain. Talk to your health care provider about how much weight gain is right for you during pregnancy.
How many pounds should I gain during pregnancy?
Guidelines from the Institute of Medicine and the National Research Council, issued in 2009, recommend the following amount of weight gain during pregnancy6:
|Pre-pregnancy Weight||Amount to Gain|
(BMI < 18.5)
(BMI 18.5 - 24.9)
(BMI 25 - 29.9)
(BMI - 30+)
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.