Obesity is abnormally high proportion of body fat.

A person becomes obese when calorie intake is always greater than the number of calories burned through activity and basic metabolic processes.

Factors that can influence obesity are:

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

Risk factors include:

• Advancing age
• Quitting smoking
• Working varied shifts
• Decreased activity
• Sedentary lifestyle
• Imbalance of excess calories versus decreased activity
• High level of fast food intake
• High alcohol consumption
• Eating foods with a high glycemic index such as refined carbohydrates (eg, instant mashed potatoes, baked white potatoes, instant rice)

Symptoms include:

• Increased weight
• Thickness around the midsection
• Obvious areas of fat deposits

Your doctor can determine if you are obese by looking at your body and assessing the percentage of body fat.

Methods of assessing body fat:

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

Tests:

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

Obesity is difficult to treat. Things that affect treatment are:

• Cultural factors
• Personal habits
• Lifestyle
• Genetics

Approaches to weight loss include:

Keep track of everything you eat and drink.

Ask your doctor about how to begin an exercise program right for you. Limit the amount of time you spend watching television and using the computer. This is especially important for children.

Your doctor or a dietitian can determine what your total calorie intake should be. This is based on:

• Your current weight
• Your weight loss goals

Portion size is also an important determinant of calorie intake. If you are obese and also have type 2 diabetes , using special portion-control plates may help you succeed in losing weight and reducing diabetes medications. *¹

Your doctor may recommend that you reduce saturated and trans fats , as well as limit the amount of refined carbohydrates that you eat. Keep fat intake under 35% of total calories eaten daily.

You may have more success at losing weight by following the Mediterranean diet or the low-carb diet , rather than the low-fat diet.*²

Behavior therapy may help you understand:

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

Research on the effectiveness of weight-loss programs is limited. They do seem to work for some people, however.

Some studies suggest that a partner or group may help you improve your diet and fitness.

Medications for weight loss are available. Medications include:

• Sibutramine (Meridia)
• Orlistat (Xenical)
• Metformin (Glucophage)

Some medications 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.

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.