Obesity raises the risk of cardiovascular diseases such as atherosclerosis, high blood pressure, angina, hyperlipidemia, myocardial infarction and heart failure by 50%. Even a small weight gain can make you short of breath when climbing stairs or walking fast, which shows how much obesity affects the heart. As obesity increases, high blood pressure also becomes more common: compared with people of normal weight, the risk of high blood pressure is 2.5 times higher in men and 4 times higher in women. Childhood obesity is a growing problem these days and is likely to continue into adult obesity. Even if obesity in childhood or adolescence does not raise blood pressure right away, high blood pressure is likely if obesity continues into adulthood.
Diabetes is one of the chronic diseases whose incidence is steadily rising. There are many factors that cause diabetes, but the most important is obesity. In fact, many people with obesity have diabetes, and losing weight often makes blood sugar much easier to control. The risk of diabetes rises by 20% for every 1 kg/m2 increase in BMI. Compared with people of normal weight, people with obesity have a 5 to 13 times higher risk of developing diabetes.
Hyperlipidemia is a condition in which blood cholesterol is 240 mg/dL or higher and triglycerides are 150 mg/dL or higher. It is a problem because it is a major cause of atherosclerosis and is linked to angina, myocardial infarction and stroke. A common question is, "I hardly eat meat, so why do I have hyperlipidemia?" In such cases, people often overeat rice or flour-based foods with salty side dishes. Rice and flour-based foods are mainly carbohydrates, but when eaten in excess they are converted into fat and stored in the body, which affects hyperlipidemia. This also explains why high triglycerides are still more common than high cholesterol in Korea, while high cholesterol is more common in Western countries. Fortunately, hyperlipidemia caused by obesity mostly improves when obesity is treated.
Skin conditions caused by obesity fall into two main types. One is stretch marks on the abdomen, calves and thighs caused by rapid weight gain. The problem is that stretch marks are very difficult to restore completely, even with surgery, medication or other treatments. The other is inflammation and contact dermatitis in areas with thick fat layers, such as the armpits and groin, where skin rubs against skin.
In people with obesity, the liver makes more fat, and fat that cannot be processed builds up in the liver, which easily leads to fatty liver. If fatty liver continues, you may notice reduced liver function and chronic fatigue. There are even reports that about 90% of people with obesity have fatty liver. In the past the biggest cause of fatty liver was alcohol, but fatty liver caused by diabetes and obesity has been increasing recently. Fortunately, fatty liver caused by obesity can improve with a low-calorie diet and weight control.
Excess weight increases the load on the joints, putting a lot of strain on the lower back, knees and ankles. In severe cases, excess weight can overload the joints and cause arthritis. One study found that every 1 kg of weight gain puts 7 kg of load on the knee joint, wearing down the cartilage. For people with obesity, it is important to lose weight to reduce the force on the joint cartilage and prevent joint damage.
Gallstone disease is a condition in which stones form in the gallbladder or bile ducts and cause pain. It may be accompanied by abdominal pain, vomiting and jaundice. Gallstones are closely linked to obesity from a high-fat diet, so good weight management is important to prevent them. However, rapid weight loss can also cause or worsen gallstones, so it is best to lose weight gradually without straining your body.
Sleep apnea is a condition in which the airway becomes blocked during sleep so that not enough oxygen is taken in, and it becomes more common as obesity becomes more severe. Fat around the neck presses on the airway, making sleep apnea more likely. Sleep apnea causes inflammation throughout the body, which speeds up aging and raises the risk of cardiovascular complications. The first-line treatment for sleep apnea is weight loss.
GERD is a condition in which stomach acid or stomach contents flow back into the esophagus, causing a burning pain or heartburn in the chest, and it increases in proportion to BMI. Abdominal obesity is thought to raise pressure in the stomach, causing acid reflux, and various inflammatory substances made by visceral fat are thought to affect the function of the esophagus and stomach. In fact, people with obesity have lower pressure in the lower esophageal sphincter, so reflux occurs more easily.
Excess body fat also upsets the balance of sex hormones. In women with obesity, both female and male hormones increase, which can cause menstrual problems, irregular periods and ovulation disorders, and even infertility. Hormonal imbalance can reduce ovarian function, and excess estrogen raises the risk of endometrial cancer and breast cancer. The recent increase in breast cancer in Korea is also strongly linked to obesity. People with obesity also often tire easily and have reduced libido. When obesity causes diabetes, sexual function may also decline.
Obesity affects not only the body but also the mind. Some people develop anxiety or depression because of difficulties in relationships or finding a job, or limits on marriage and sexual life. Some people lack confidence in front of others because of their appearance and begin to avoid social contact, and reduced self-confidence can lower work performance and overall quality of life.
Obesity can lead to eating disorders such as anorexia nervosa, bulimia nervosa and binge eating disorder. These are not simple eating problems but mental illnesses. People with these eating disorders show abnormal eating behaviors such as extreme dieting or binge eating, and after bingeing they may make themselves vomit or take drugs such as diuretics for fear of gaining weight. They may also become pathologically obsessed with their weight.
