Introduction: Obesity and overweight is gradually becoming a major public health problem worldwide leading to cardiovascular problems, type 2 DM and adult obesity. The main reason of the problem is change in lifestyle specially the food habit and sedentary life. This study designed for understanding the knowledge, attitude and practice about healthy eating and physical activity among adolescent age group [10–19] years. Methodology:The cross sectional study was carried on 360 students from 12 government schools in Guwahati city between June 15^thto 25th august, 2016. Result: Out of 360 students 192 [53.35%] know that family history and 268 [74.44%] students know that less physical activity cause overweight and obesity. Most of the respondents don’t know that fast food [54.44%] and carbonated soft drinks [82.22%] can cause overweight and obesity.