Obesity

Obesity is an abnormally high proportion of body fat.

Causes

A person becomes obese when calorie intake is consistently greater than the number of calories burned through activity and basic metabolic processes.
Several factors can influence Obesity, including:

Genetic tendency
Biologic factors (such as the amount and activity of certain chemicals in the body)
Medications (corticosteroids, antidepressants, and antipsychotics)
Underactive thyroid
Cushing's disease
Polycystic ovary syndrome
Froehlich's syndrome
Prader-Willi syndrome
Laurence-Moon-Biedl syndrome

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Advancing age
Quitting smoking
Working varied shifts
Decreased activity
Sedentary lifestyle
Imbalance of excess calories versus decreased activity

Symptoms

Symptoms include:

Increased weight
Thickness around the midsection
Obvious areas of fat deposits

Diagnosis

The doctor can often determine if you are obese by looking at your body and assessing the percentage of body fat.
Methods of assessing body fat include:

Height and weight tables
Body mass index
Measuring body folds with a caliper
Measuring waist-to-hip ratio
Water-displacement tests

Tests may include:

Blood tests – to rule out other medical conditions that may cause excess body weight

Treatment

Obesity is difficult to treat. Cultural factors, personal habits, lifestyle, and genetics all affect Obesity treatment.
Approaches to weight loss include:
Keep a Food Diary
Keep track of everything you eat and drink.
Increase Physical Activity and Exercise
Ask your doctor about how to begin an appropriate exercise program. Limit the amount of time you spend watching television and using the computer. This is especially important for children.
Reduce Total Calories Eaten Per Day
Your doctor or a dietitian can determine what your total calorie intake should be, based on:

Your current weight
Your weight loss goals

Reduce Dietary Fat
Keep fat intake under 30% of total calories eaten daily.
Behavior Therapy
Behavior therapy may help you understand:

When you tend to overeat
Why you tend to overeat
How to combat overeating tendencies

Weight Loss Programs
Research on the effectiveness of weight loss programs is limited. They do seem to work for some people, however.
Team Up with a Partner
Some studies suggest that a partner or group may help you improve your diet and fitness.
Medications
Medications for weight loss are available, but some have led to serious complications. Do not use over-the-counter or herbal remedies for weight loss unless your doctor monitors you for side effects. Your doctor can make recommendations about prescription weight loss drugs.
Bariatric Surgery
Surgical procedures reduce the size of the stomach and rearrange the digestive tract. The smaller stomach can only hold a tiny portion of food at a time. Operations include gastric bypass and laparoscopic gastric banding. These procedures are only an option for people who are dangerously overweight, due to the potential for serious complications.
Note:
Complications of untreated obesity include:

Decreased energy
Heart disease
High blood pressure
Type 2 diabetes
Gallstones
Worsening arthritis symptoms
Increased risk of certain cancers
Gout
Infertility
Sleep apnea
Poor self-image, depression

Prevention

Preventing obesity can be difficult because so many factors influence your weight. General recommendations include:

Consult your doctor or a dietitian about an appropriate number of calories to eat per day.
Eat a diet with no more than 30% of daily calories from fat.
Follow a medically approved, appropriate exercise program.
Talk to your doctor or a qualified exercise professional about working physical activity into your daily life.
Ask a dietitian for help planning a diet that will help you maintain a healthy weight or lose weight if necessary.