How does Obesity affect Health?

While obesity itself is mainly of cosmetic concern, a large number of medical conditions have been associated with obesity. Disease associations may be dependent or independent of the distribution of adipose tissue.

Central Obesity

Central obesity (male-type or waist-predominant obesity, characterised by a high waist-hip ratio), is an important risk factor for the metabolic syndrome, the clustering of a number of diseases and risk factors that heavily predispose for cardiovascular disease. These are:

diabetes mellitus type 2
high blood pressure
high blood cholesterol
triglyceride levels (combined hyperlipidemia)

There alterations in the body's response to insulin (insulin resistance), a proinflammatory state and an increased tendency to thrombosis.

Apart from the metabolic syndrome, obesity is also correlated with a variety of other complications. For some of these complaints, it has not been clearly established to what extent they are caused directly by obesity itself, or have some other cause (such as limited exercise) that causes obesity as well.

Cardiovascular: congestive heart failure, enlarged heart and its associated arrhythmias and dizziness, cor pulmonale, varicose veins, and pulmonary embolism
Endocrine: polycystic ovarian syndrome (PCOS), menstrual disorders, and infertility
Gastrointestinal: gastroesophageal reflux disease (GERD), fatty liver disease, cholelithiasis (gallstones), hernia, and colorectal cancer
Renal and genitourinary: erectile dysfunction, urinary incontinence, chronic renal failure, hypogonadism (male), breast cancer (female), uterine cancer (female), stillbirth
Integument (skin and appendages): stretch marks, acanthosis nigricans, lymphedema, cellulitis, carbuncles, intertrigo
Musculoskeletal: hyperuricemia (which predisposes to gout), immobility, osteoarthritis, low back pain
Neurologic: stroke, meralgia paresthetica, headache, carpal tunnel syndrome, dementia
Respiratory: dyspnea, obstructive sleep apnea, hypoventilation syndrome, Pickwickian syndrome, asthma
Psychological: Depression, low self esteem, body dysmorphic disorder, social stigmatization

While being severely obese has many health ramifications, those who are somewhat overweight face little increased mortality or morbidity. Osteoporosis is known to occur less in slightly overweight people.