Although definition of obesity and overweight has changed over time, it can be defined as an excess of body fat (BF). There is no consensus on a cut-off point for excess fatness of overweight or obesity in children and adolescents. A study by conducted by Williams et al. (1992), on 3,320 children in the age-group of 5–18 years classified children as fat if their percentage of body fat was at least 25% for males and 30% for females, respectively.The Center for Disease Control and Prevention defined overweight as at or above the 95th percentile of body mass index (BMI) for age and “at risk for overweight” as between 85th to 95th percentile of BMI for age.European researchers classified overweight as at or above 85th percentile and obesity as at or above 95th percentile of BMI.

An Indian research study has defined overweight and obesity as overweight (between ≥85th and <95th percentile) and obesity (≥95th percentile).Another study has followed World Health Organization 2007 growth reference for defining overweight and obesity.