Obesity is a state of excess storage of body fat in the body. Although there is no clear cut measurement of obesity, Body mass index or BMI or Quetelet index is a reasonably good measure of obesity (BMI = weight/height2, where weight is in kilograms and height is in meters). Estimation of percentage of body fat is another measure for obesity (Uwaifo and Arioglu, 2009). In men, body fat >25% is suggestive of obesity and in women, >33% is an indication of obesity (Uwaifo and Arioglu, 2009).
The most widely accepted definition of obesity is that by the WHO: “for adults, grade 1 overweight (commonly and simply called overweight) is a BMI of 25-29. 9 kg/m2, grade 2 overweight (commonly called obesity) is a BMI of 30-39. 9 kg/m2 and grade 3 overweight (commonly called severe or morbid obesity) is a BMI greater than or equal to 40 kg/m2” (Uwaifo and Arioglu, 2009). In children, BMI greater than 85th percentile is considered as over weight and that above 95th percentile is considered as obesity (Uwaifo and Arioglu, 2009). According to statistics, atleast 100 million adults in the United States suffer from overweight or obesity.
31% of men and 33% of women above 19years of age are either overweight or obese (Uwaifo and Arioglu, 2009). The incidence in children is about 20-25% (Uwaifo and Arioglu, 2009). The prevalence of obesity is higher in certain minority groups like Mexican Americans, Pima Indians and African Americans either due to genetic and familial factors or due to sedentary lifestyles. The prevalence in both the sexes is equal (Uwaifo and Arioglu, 2009). The main cause for obesity is positive imbalance between calorie intake and calorie expenditure.
However, there are many other factors which contribute to obesity. Obesity runs in families probably due to genetic aspects or due to common lifestyle habits and shared diet (Galleta and Khandwalla, 2005). Depression, boredom and anger increase the intake of food and contribute to obesity. Sedentary habits, lack of exercise and physiological states like pregnancy and lactation contribute to obesity. Certain diseases like Cushing syndrome, hypothyroidism, depression, polycystic ovarian syndrome and Prader-Willi syndrome also lead to obesity (Galleta and Khandwalla, 2005).
For majority of over weight and obese people, the best treatment of obesity is to eat less and perform more exercises and physical activity. Decreasing calorie intake by 500 calories or expending extra 500 calories during exercise sessions will help decrease weight by about a pound per week (Galleta and Khandwalla, 2005). Exercise of atleast 30 minutes for 5 times a week is essential to achieve weight loss. In children, weight loss must not be aimed at. Rather, the aim must be to reduce the rate of weight gain to such an extent that they fall into the expected profile gradually.