The food that we eat is required for the growth and energy expenditure by our body. Our body needs energy to perform its functions. Like our heart needs energy to pump blood, our liver needs energy for the metabolism of food, kidneys need energy to throw out body wastes and so on. Apart from this, we need energy for our day- to- day activities like walking, talking, sitting and so on. Ideally, the food intake should be equal to the energy expenditure. Obesity results when a person ingests more calories than he or she can burn off. If this happens regularly over a period of time, the body will store the extra calories as fat. The body is able to burn off calories as energy needed throughout the day, but if the energy is not burned away, it will be stored as fat. Every person has his or her own metabolic rate. This is the rate at which calories are used or burned off within the body. People who take a lot of exercise or are employed in strenuous jobs usually have a very high metabolic rate. They require a lot of calories, but burn them off easily. People who do not take a lot of exercise or are involved in jobs such as office work do not need as many calories.The body stores extra calories as fat and if a person continually eats calories that he or she cannot burn off, obesity may occur.

Overweight is weighing more than normal, necessary or allowed, especially having more body weight than is considered normal or healthy for one's age or build.

Obesity is defined as an abnormal accumulation of body fat, usually 20% or more over an individual's ideal body weight, which is associated with increased risk of illness, disability and death. The World Health Organization (WHO) defines "overweight" as a BMI equal to or more than 25, and "obesity" as a BMI equal to or more than 30. These cut-off points provide a benchmark for individual assessment but there is evidence that risk of chronic disease in population increases progressively from a BMI of 21. On the basis of body fat percentage, women with over 30% body fat and men with over 25% body fat are considered obese. A certain amount of body fat is necessary for storing energy, heat insulation, shock absorption, and other functions. The normal amount of body fat (expressed as percentage of body fat) is between 25%-30% in women and 18%-23% in men.

Obesity and overweight pose a major risk for serious diet-related chronic diseases, including type 2 diabetes, cardiovascular disease, hypertension and stroke, and certain forms of cancer. The health consequences range from increased risk of premature death, to serious chronic conditions that reduce the overall quality of life. Of especial concern is the increasing incidence of child obesity.

FACTS ABOUT OBESITY