Obesity is not just a cosmetic consideration; it is harmful to one’s health as it is a risk factor for many conditions. Patients with a BMI over 40 have a reduced life expectancy. Obesity also increases the risk of developing a number of chronic diseases, including the following:
- Insulin resistance
Insulin is necessary for the transport of blood glucose (sugar) into the cells of muscle and fat (which the body uses for energy). By transporting glucose into cells, insulin keeps the blood glucose levels in the normal range. Insulin resistance (IR) is the condition whereby there is diminished effectiveness of insulin in transporting glucose (sugar) into cells. Fat cells are more insulin resistant than muscle cells; therefore, one important cause of insulin resistance is obesity. The pancreas initially responds to insulin resistance by producing more insulin. As long as the pancreas can produce enough insulin to overcome this resistance, blood glucose levels remain normal. This insulin resistance state (characterized by normal blood glucose levels and high insulin levels) can last for years. Once the pancreas can no longer keep up with producing high levels of insulin, blood glucose levels begin to rise, resulting in type 2 diabetes, thus insulin resistance is a pre-diabetes condition.
- Type 2 (adult-onset) diabetes
The risk of type 2 diabetes increases with the degree and duration of obesity. Type 2 diabetes is associated with central obesity; a person with central obesity has excess fat around his/her waist (apple-shaped figure).
- High blood pressure (hypertension)
Hypertension is common among obese adults.
- Heart attack
A prospective study found that the risk of developing coronary artery disease increased three to four times in women who had a BMI greater than 29. A Finnish study showed that for every 1 kilogram (2.2 pounds) increase in body weight, the risk of death from coronary artery disease increased by 1%. In patients who have already had a heart attack, obesity is associated with an increased likelihood of a second heart attack.
- Congestive heart failure
Obesity is a risk factor for cancer of the colon in men and women, cancer of the rectum and prostate in men, and cancer of the gallbladder and uterus in women. Obesity may also be associated with breast cancer, particularly in postmenopausal women. Fat tissue is important in the production of estrogen, and prolonged exposure to high levels of estrogen increases the risk of breast cancer.
- Gout and gouty arthritis
- Osteoarthritis (degenerative arthritis) of the knees, hips, and the lower back
- Sleep apnea
In general, overweight and obesity indicate a weight greater than what is healthy. Obesity is a chronic condition defined by an excess amount of body fat. A certain amount of body fat is necessary for storing energy, heat insulation, shock absorption, and other functions.