Being overweight or obese means your weight is above an ideal weight range. Excess weight creates increased risk of heart disease, certain cancers, and other serious illnesses like diabetes. One tool used to estimate ideal and overweight ranges is called the body mass index (BMI). This scale determines weight ranges based on height. BMI levels include:

• Ideal weight range: 18.5-24.9
• Overweight: 25.0-29.9
• Obese: 30.0 or above
• Morbid obesity: 40 or above (35 and above with current health condition like diabetes or high blood pressure)

There are slightly different categories for teens and children.

Calories are taken in through food. They are used through physical activity and basic body functions. Excess weight gain occurs when this relationship is not kept in balance. High caloric intake and low usage will cause weight gain. If this happens regularly it will lead to obesity.

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
• Working varied shifts
• Decreased activity
• Sedentary lifestyle—Getting too little exercise and spending too much time in front of a TV or computer can contribute to obesity in children and adults.
• 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)
• Eating until full and eating quickly

Symptoms include:

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

Obesity is diagnosed by visual exam and body measurements using:

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

To rule out other medical conditions that may cause excess body weight, your doctor may order:

• Blood tests

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

• Cultural factors
• Personal habits
• Lifestyle
• Genetics

There are many different approaches to treating obesity. You are more likely to successfully lose weight and keep it off by using a combination of strategies, like diet, exercise, counseling, and/or medication. Talk to your doctor or ask for a referral to a dietician . They can help you develop a plan that is best for you. Plans for weight loss may include:

Your doctor may recommend that you:

• Reduce saturated and trans fats
• Limit the amount of refined carbohydrates that you eat
• Keep fat intake under 35% of total calories eaten daily

According to a recent study, the key to weight loss is in reducing the amount of calories that you consume, rather than following a specific kind of diet (like a low-carb diet). It is much more important to choose a low calorie diet you can stick with for the long haul. A dietitian can help you with your total calorie intake goal. This is based on your:

• Current weight
• Weight loss goals

Portion size also plays an important role. Using special portion control plates may help you succeed.

Keep track of everything you eat and drink.

Ask your doctor about an exercise program.

Add bits of activity through your day. Take stairs instead of elevators. Park a little further away. Limit the amount of time you spend watching television and using the computer. This is particularly important for children.

Behavior therapy may help you understand:

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

Weight loss programs do seem to work for some people. Some studies also suggest that a partner or group may help you improve your diet and fitness.

Weight loss medications include:

• Sibutramine (Meridia) —suppresses appetite
• Orlistat (Xenical) —interferes with the absorption of fat from the intestines

Medications alone are not a viable option for losing weight and keeping it off. Some have led to serious side effects. Do not use over-the-counter or herbal remedies without talking to your doctor.

The problem of obesity, of course, is not restricted to adults. There is evidence that the same changes in diet, exercise, and other behaviors can help children and teens lose weight. For example, kids may find success by participating in group therapy that focuses on diet and behavior changes.

When added to lifestyle changes, medications (eg, sibutramine, orlistat) have also been shown to help obese children and adolescents lose weight, though careful monitoring for potential adverse effects is required.

Surgical procedures reduce the size of the stomach. It will also rearrange the digestive tract. The smaller stomach can only hold a tiny portion of food at a time. Operations include:

• Gastric bypass
• Laparoscopic gastric banding

These procedures can have serious complications. They are only an option for people who are dangerously overweight.