What is Obesity and What Causes it?

Obesity means having excess body fat. Even a modest weight loss of 5%-10% of initial weight and the long-term maintenance of that weight loss can bring significant health benefits by lowering blood pressure and lowering the risks of diabetes and heart disease.

For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the "body mass index" (BMI).

For children and teens, BMI ranges above a normal weight have different labels (overweight and obese). Defining Overweight and Obesity.

In general, overweight and obesity indicate a weight greater than what is considered healthy. Obesity is a chronic condition defined by an excess amount body fat. Obesity is best defined by using the body mass index. The body mass index is calculated using a person's height and weight.

The body mass index (BMI) equals a person's weight in kilograms (kg) divided by their height in meters (m) squared. Since BMI describes body weight relative to height, it is strongly correlated with total body fat content in adults.

What causes obesity?

Many reason what cause obesity. Eat more calories than what we need and what body can burns or metabolizes will gains weight becouse body will store the excess energy as fat.The role of carbohydrates in weight gain is not clear. Carbohydrates increase blood glucose levels, which in turn stimulate insulin release by the pancreas, and insulin promotes the growth of fat tissue and can cause weight gain. This higher insulin release, some scientists believe, contributes to weight gain.

Genetics. A person is more likely to develop obesity if one or both parents are obese. Genetics also affect the hormones involved in the regulation of fat.Leptin (hormone produced in fat cells and also in the placenta)controls weight by signaling the brain to eat less when body fat stores are too high.

Overeating. Overeating leads to weight gain, especially if the diet is high in fat. Epidemiologic studies have shown that diets high in fat contribute to weight gain.

Frequency of eating. The relationship between frequency of eating and weight is somewhat controversial. There are many reports of overweight people eating less often than people with normal weight. One possible explanation is that small frequent meals produce stable insulin levels, whereas large meals cause large spikes of insulin after meals.

Slow metabolism, Women have less muscle mass than men. As a result, a slower metabolism than men, and weight loss more difficult than men.

 Physical inactivity. Sedentary people burn fewer calories than people who are active.

Medications. Weight gain may also be seen with some high blood pressure medications and antihistamines. The reason for the weight gain with the medications differs for each medication.

Psychological factors.For some people, emotions influence eating habits. While most overweight people have no more psychological disturbances than normal weight people, about 30% of the people who seek treatment for serious weight problems have difficulties with binge eating.