Prevention & Risk Assessment
What causes obesity?
In many ways, obesity is a puzzling disease. How the body regulates weight and body fat is not well understood. On one hand, the cause appears to be simple in that if a person consumes more calories than he or she expends as energy, then he or she will gain weight.
However, the risk factors that determine obesity can be a complex combination of genetics, socioeconomic factors, metabolic factors, and lifestyle choices, as well as other factors. Some endocrine disorders, diseases, and medications may also exert a powerful influence on an individual's weight.
Factors which may influence the occurrence of obesity include, but are not limited to, the following:
- Genetics - Studies have shown that a predisposition toward obesity can be inherited. Although researchers have identified several genes that appear to be associated with obesity, most believe that one gene is not responsible for the entire obesity epidemic. The majority of current and future research aims to better understand the interaction between these gene variations and our ever-changing environment in the development of obesity.
- Metabolic factors How a particular person expends energy is different from how someone else's body uses energy. Both metabolic and hormonal factors are not the same for everyone, but these factors play a role in determining weight gain. Recent studies show that levels of ghrelin, a peptide hormone known to regulate appetite, and other peptides in the stomach, play a role in triggering hunger and producing a feeling of fullness (satiety).
- Socioeconomic factors- There is a strong relationship between economic status and obesity, especially among women. Women who are poor and of lower social status are more likely to be obese than women of higher socioeconomic status. The occurrence of obesity is also highest among minority groups, especially among women.
- Lifestyle choices Overeating, along with a sedentary lifestyle, contributes to obesity. These are lifestyle choices that can be affected by behavior change.
- Eating a diet in which a high percentage of calories come from sugary, high-fat, refined foods promotes weight gain. And, as more U.S. families eat on the go, high-calorie foods and beverages are often selected.
- Lack of regular exercise contributes to obesity in adults and makes it difficult to maintain weight loss. In children, inactivity, such as watching television or sitting at a computer, contributes to obesity.
Who is affected by obesity?
Physical factors contributing to excess body fat in adolescents include the following:
- Increased insulin levels
- Elevated lipid and lipoprotein levels
- Elevated blood pressure
Behavioral and other factors contributing to a positive energy balance stored as fat over long periods of time include the following:
- Excessive intake of high energy foods
- Inadequate exercise in relation to age
- More sedentary lifestyle
- Low metabolic rate
- Increased insulin sensitivity
What are the symptoms of obesity?
The following are the most common symptoms that indicate an adolescent is obese. However, each adolescent may experience symptoms differently. Symptoms may include:
- Facial features often appear disproportionate
- Adiposity (fat cells) in the breast region in boys
- Large abdomen (white or purple marks are sometimes present)
- In males, external genitals may appear disproportionately small
- Puberty may occur early
- Increased adiposity in the upper arms and thighs
- Genu valgum (knock kneed) is common
Adolescents who are obese often experience significant social pressure, stress, and difficulties accomplishing developmental tasks. Psychologic disturbances are also very common. The symptoms of obesity may resemble other conditions or medical problems. Always consult your adolescent's doctor for a diagnosis.
Health effects of obesity
Obesity has a far-ranging negative effect on health. Each year obesity-related conditions cost over 100 billion dollars and cause premature deaths in the U.S. The health effects associated with obesity include, but are not limited to, the following:
- High blood pressure: Additional fat tissue in the body needs oxygen and nutrients in order to live, which requires the blood vessels to circulate more blood to the fat tissue. This increases the workload of the heart because it must pump more blood through additional blood vessels. More circulating blood also means more pressure on the artery walls. Higher pressure on the artery walls increases the blood pressure. In addition, extra weight can raise the heart rate and reduce the body's ability to transport blood through the vessels.
- Diabetes: Obesity is the major cause of type 2 diabetes. Obesity can cause resistance to insulin, the hormone that regulates blood sugar. When obesity causes insulin resistance, the blood sugar becomes elevated. Even moderate obesity dramatically increases the risk of diabetes.
- Heart disease: Atherosclerosis (hardening of the arteries) occurs more often in obese people compared to those who are not obese. Coronary artery disease is also more prevalent because fatty deposits build up in arteries that supply the heart. Narrowed arteries and reduced blood flow to the heart can cause chest pain (angina) or a heart attack. Blood clots can also form in narrowed arteries and cause a stroke.
- Joint problems, including osteoarthritis: Obesity can affect the knees and hips because of the stress placed on the joints by extra weight. Joint replacement surgery, while commonly performed on damaged joints, may not be an advisable option for an obese person because the artificial joint has a higher risk of loosening and causing further damage.
- Sleep apnea and respiratory problems: Sleep apnea, which causes people to stop breathing for brief periods, interrupts sleep throughout the night and causes sleepiness during the day. It also causes heavy snoring. Respiratory problems associated with obesity occur when added weight of the chest wall squeezes the lungs and causes restricted breathing. Sleep apnea is also associated with high blood pressure.
- Cancer: In women, being overweight contributes to an increased risk for a variety of cancers including breast, colon, gallbladder, and uterus. Men who are overweight have a higher risk of colon and prostate cancers.
- Metabolic syndrome: The National Cholesterol Education Program has identified metabolic syndrome as a complex risk factor for cardiovascular disease. Metabolic syndrome consists of six major components: abdominal obesity, elevated blood cholesterol, elevated blood pressure, insulin resistance with or without glucose intolerance, elevation of certain blood components that indicate inflammation, and elevation of certain clotting factors in the blood.
- Psychosocial effects: In a culture where often the ideal of physical attractiveness is to be overly thin, people who are overweight or obese frequently suffer disadvantages. Overweight and obese persons are often blamed for their condition and may be considered to be lazy or weak-willed. It is not uncommon for overweight or obese conditions to result in persons having lower incomes or having fewer or no romantic relationships. Disapproval of overweight persons expressed by some individuals may progress to bias, discrimination, and even torment