What is Obesity?

Obesity is an excess proportion of total body fat. A person is considered obese when his or her weight is 20% or more above normal weight. The most common measure of obesity is the body mass index or BMI. A person is considered overweight if his or her BMI is between 25 and 29.9; a person is considered obese if his or her BMI is over 30.

"Morbid obesity" means that a person is either 50%-100% over normal weight, more than 100 pounds over normal weight, has a BMI of 40 or higher, or is sufficiently overweight to severely interfere with health or normal function.

What Causes Obesity...

Obesity occurs when a person consumes more calories than he or she burns. For many people this boils down to eating too much and exercising too little. But there are other factors that also play a role in obesity. These may include:

• Age. As you get older, your body's ability to metabolize food slows down and you do not require as many calories to maintain your weight. This is why people note that they eat the same and do the same activities as they did when they were 20 years old, but at age 40, gain weight.

• Gender. Women tend to be more overweight than men. Men have a higher resting metabolic rate (meaning they burn more energy at rest) than women, so men require more calories to maintain their body weight. Additionally, when women become postmenopausal, their metabolic rate decreases. That is partly why many women gain weight after menopause.

• Genetics. Obesity (and thinness) tends to run in families. In a study of adults who were adopted as children, researchers found that participating adult weights were closer to their biological parents' weights than their adoptive parents'. The environment provided by the adoptive family apparently had less influence on the development of obesity than the person's genetic makeup. In fact, if your biological mother is heavy as an adult, there is approximately a 75% chance that you will be heavy. If your biological mother is thin, there is also a 75% chance that you will be thin. Nevertheless, people who feel that their genes have doomed them to a lifetime of obesity should take heart. Many people genetically predisposed to obesity do not become obese or are able to lose weight and keep it off.

• Environmental factors. Although genes are an important factor in many cases of obesity, a person's environment also plays a significant role. Environmental factors include lifestyle behaviors such as what a person eats and how active he or she is.

• Physical activity. Active individuals require more calories than less active ones to maintain their weight. Additionally, physical activity tends to decrease appetite in obese individuals while increasing the body's ability to preferentially metabolize fat as an energy source. Much of the increase in obesity in the last 20 years is thought to have resulted from the decreased level of daily physical activity.

• Psychological factors. Psychological factors also influence eating habits and obesity. Many people eat in response to negative emotions such as boredom, sadness, or anger. While most overweight people have no more psychological disturbances than people at their normal weight, about 30% of people who seek treatment for serious weight problems have difficulties with binge eating. During a binge-eating episode, people eat large amounts of food while feeling they can't control how much they are eating.

• Illness. Although not as common as many believe, there are some illnesses that can cause obesity. These include hormone problems such as hypothyroidism (poorly acting thyroid slows metabolism), depression, and some rare diseases of the brain that can lead to overeating.

• Medication. Certain drugs, such as steroids and some antidepressants, may cause excessive weight gain.

Emotional Aspect of Obesity...

One of the most painful aspects of obesity may be the emotional suffering it causes. American society places great emphasis on physical appearance, often equating attractiveness with slimness or muscularity. In addition, many people wrongly stereotype obese people as gluttonous, lazy, or both. However, more and more evidence contradicts this assumption. Obese people often face prejudice or discrimination at work, at school, while looking for a job, and in social situations. Feelings of rejection, shame, or depression are common.

When To Seek Help for Obesity...

You should call your doctor if you are having emotional problems related to your obesity, need help losing weight, or if you fall into either of the following categories.

• If your BMI is 30 or greater, you're considered obese. You should talk to your doctor about losing weight since you are at high risk of having health problems.

• If you have an "apple shape" -- a so-called, "potbelly" or "spare tire" -- you carry more fat in and around your abdominal organs. Fat in your abdomen increases your risk of many of the serious conditions associated with obesity. Women's waist measurement should fall below 35 inches. Men's should be less than 40 inches. If you have a large waist circumference, talk to your doctor about how you can lose weight.

Health Problems of being overweight...

Obesity is bad news for both body and mind. Not only can it make a person feel tired and uncomfortable, carrying extra weight puts added stress on the body, especially the bones and joints of the legs. As they get older, kids and teens who are overweight are more likely to develop diabetes and heart disease.

The health problems that affect overweight teens include:

• Blount's disease. Excess weight on growing bones can lead to this bone deformity of the lower legs.

• Arthritis. Wear and tear on the joints from carrying extra weight can cause this painful joint problem at a young age.

• Slipped capital femoral epiphyses (SCFE). Obese children and teens are at greater risk for this painful hip problem. SCFE requires immediate attention and surgery to prevent further damage to the joint.

• Asthma. Obesity is associated with breathing problems that can make it harder to keep up with friends, play sports, or just walk from class to class.

• Sleep apnea. This condition (where a person temporarily stops breathing during sleep) is a serious problem for many overweight kids and adults. Not only does it interrupt sleep, sleep apnea can leave people feeling tired and affect their ability to concentrate and learn. It also may lead to heart problems.

• High blood pressure. When blood pressure is high, the heart must pump harder and the arteries must carry blood that's moving under greater pressure. If the problem continues for a long time, the heart and arteries may no longer work as well as they should. Although rare in most teens, high blood pressure, or hypertension, is more common in overweight or obese teens.

• High cholesterol. Long before getting sick, obese teens may have abnormal blood lipid levels, including high cholesterol, low HDL ("good") cholesterol, and high triglyceride levels. These increase the risk of heart attack and stroke when a person gets older.

• Gallstones. An accumulation of bile that hardens in the gallbladder forms gallstones. These may be painful and require surgery.

• Fatty liver. When fat accumulates in the liver, it can cause inflammation, scarring, and permanent liver damage.

• Pseudotumor cerebri. This is a rare cause of severe headaches in obese teens and adults. There is no tumor, but pressure builds in the brain. In addition to headaches, symptoms may include vomiting, an unsteady way of walking, and vision problems that may become permanent if not treated.

• Polycystic ovary syndrome (PCOS). Girls who are overweight may miss periods — or not get their periods at all — and may have elevated testosterone (the male hormone) levels in the blood. Although it is normal for girls to have some testosterone in their blood, too much can interfere with normal ovulation and may cause excess hair growth, worsening acne, and male-type baldness. PCOS is associated with insulin resistance, a precursor to developing type 2 diabetes. Women who are overweight also might have fertility problems.

• Insulin resistance and diabetes. When there is excess body fat, insulin is less effective at getting glucose, the body's main source of energy, into cells. More insulin becomes needed to maintain a normal blood sugar. For some overweight teens, insulin resistance may progress to diabetes (high blood sugar).

• Depression. People who are obese are more likely to be depressed and have lower self-esteem.

Luckily, it's never too late to make changes that can effectively control weight and the health problems it causes. Those changes don't have to be big. For a start, make a plan to cut back on sugary beverages, pass up on seconds, and get more exercise, even if it's just 5–10 minutes a day. Build your way up to big changes by making a series of small ones. And don't be afraid to ask for help!