What is obesity?
Obesity is defined as a generalized accumulation of body fat. An adolescent is considered obese if he (or she) is significantly over the ideal weight for his or her height.
Overweight refers to increased body weight in relation to height, but this may be due to excess body fat and/or lean muscle. (In professional athletes, for example, overweight does not necessarily mean too fat).
Research studies suggest that overweight adolescents may become overweight adults.
What causes obesity?
During the 1990s, one physiologist proposed a set point theory which has continued to gain support. This theory suggests that weight is determined by complex interactions of neural, hormonal, and metabolic factors. Genetic and familial influences contribute to metabolic rates, and physical activity levels are important to energy expenditure.
Experts now identify and address two types of obesity:
What are the physical side effects of obesity?
- Endogenous: obesity with specific organic cause or origin
- Exogenous: obesity caused by simple excessive caloric intake, genetic/familial, psychogenic, or mixed factors
Physical factors contributing to excess body fat in adolescents include the following:
How do adolescents become obese?
- Increased insulin levels
- Elevated lipid and lipoprotein levels
- Elevated blood pressure
Over long periods of time, many behaviors can lead to obesity, including:
What are the symptoms of obesity?
- Excessive intake of high-calorie foods
- Inadequate exercise in relation to age
- More sedentary lifestyle
- Low metabolic rate
- Increased insulin sensitivity
The following are the most common symptoms that indicate an adolescent is obese. However, each adolescent may experience symptoms differently. Symptoms may include:
Adolescents who are obese often experience significant social pressure, stress, and difficulties accomplishing developmental tasks. Psychological disturbances are also very common. The symptoms of obesity may resemble other conditions or medical problems, and a physician should always confirm the diagnosis.
- Facial features often appear disproportionate
- In males, fat cells in the breast region
- Large abdomen (sometimes with white or purple marks)
- In males, external genitals may appear disproportionately small
- Early onset of puberty
- Increased number of fat cells in the upper arms and thighs
- Symptoms of knock knees
How is obesity diagnosed?
Obesity is always diagnosed by a physician, and body mass index (BMI) is usually used to help confirm the diagnosis. Two categories of obesity are defined:
- BMI at the 95th percentile or more for age and sex, or BMI of more than 30 (whichever is smaller). BMI findings in this category indicate the need for a complete medical work-up.
- BMI between the 85th and 95th percentile, or BMI equal to 30 (whichever is smaller). Findings in this category suggest the need for a second level screening which includes evaluation of the following five health risks:
What is the treatment for obesity?
- Family history of cardiovascular disease
- Total cholesterol levels of parents
- Parental diabetes or obesity
- Elevated blood pressure
- Total cholesterol level
- Large increases in BMI assessments from year to year
- Concerns about weight, including personal (emotional or psychological) concerns related to weight and perception of self as overweight
The specific treatment for obesity will be determined by the adolescent's physician based on the following factors:
What are the treatments for obesity?
- The adolescent's age, overall health, and medical history
- Extent of the condition
- The adolescent's tolerance for specific medications, procedures, or therapies
- The child or parent’s opinion or preference
The treatment for obesity usually involves a nutritionist, qualified mental health professionals, and an exercise specialist. Specific actions may include the following:
Treatment goals should be realistic, focus on modest reduction of food intake and changes in eating habits, and incorporate a healthy exercise-oriented lifestyle.
- Nutritional and individual diet counseling
- Modification of diet and caloric content
- Increased exercise or participation in an appropriate exercise program
- Behavior modification
- Individual or group therapy focused on changing behaviors and confronting feelings related to weight and normal developmental issues
- Support and encouragement for making changes and following recommended treatment recommendations
How can obesity be prevented?
Specific programs or procedures to prevent obesity have not been identified at this time. Encouraging healthy eating habits and realistic attitudes toward weight and diet are important. Early detection and intervention into unhealthy eating and lifestyle habits can impact weight-related issues, enhance the adolescent's normal growth and development, and improve the quality of life experienced by adolescents with a physical predisposition or behavioral tendencies toward obesity.
Determining Body Mass Index (BMI)
What is body mass index (bmi)?
Determining how much an adolescent should weigh is not a simple matter of looking at an insurance height-weight chart, but includes considering the amount of bone, muscle, and fat in his/her body's composition. The amount of fat is the critical measurement.
A good indicator of how much fat an adolescent carries is the body mass index (BMI). Although it is not a perfect measure, it gives a fairly accurate assessment of how much of an adolescent's body is composed of fat.
To calculate BMI using the English formula:
Example: a person who weighs 165 pounds and is 5 feet 4 inches tall has a BMI of 28.
- BMI can be calculated using pounds and inches.
- BMI = Weight in Pounds x 703 divided by
(Height in Inches) x (Height in Inches)
To calculate BMI using the Metric formula:
- 165 lbs x 703 = 28 divided by
(64 inches) x (64 inches)
Example, a person who weighs 99.79 kilograms and is 1.905 meters tall has a BMI of 27.5.
- BMI can be calculated using kilograms and meters.
- BMI = Weight in Kilograms divided by
(Height in Meters) x (Height in Meters)
BMI between 25 and 29 is considered overweight. Any measurement over 30 is considered obese.
99.79 Kg = 27.5 divided by
(1.905 Meters) x (1.905 Meters)
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Obesity - Departments & Programs - Children's National Medical Center