Obesity has become the most common nutritional disorder in Western societies.
Obesity is defined as excessive accumulation of fat in the body, causing an increase in body weight beyond the limitation of physical requirement.
It is generally accepted that a person is obese when he or she has a Body Mass Index of 30 or over.
Obesity is commonly caused by consumption of more food than is required for daily activities. Excessive alcohol intake and a sedentary lifestyle also increase the risk.
Heritability studies have indicated that genetic factors may also be responsible for up to 70% of the variation in people's weight. The lack of certain gene products such as the hormone leptin increases appetite and decreases metabolic rate. This induces the growth of fat cells and weight gain.
Various health complications such as diabetes mellitus, hypertension, cardiovascular diseases, coronary artery disease, colon cancer, gallbladder disease, knee osteoarthritis, gout, low back pain, sleep apnea (temporary absence or cessation of breathing during sleep), are co-morbid in obese persons.
References:
"Obesity" Concise Medical Dictionary. Oxford Reference Online. Oxford University Press. 17 October 2007.
Yanovski, J. & Yanovski S. (1999) Recent advances in basic obesity research. JAMA, 282, 1504-1506.
Must A, Spadano J, Coakley EH, Field AE, Colditz G, Dietz WH. The disease burden associated with overweight and obesity. JAMA 1999; 282: 1523 -1529.[Medline]
Mikhail, N., Golub, M. & Tuck, M. (1999) Obesity and hypertension. Prog Cardiovasc Dis, 42, 39-58.