Childhood obesity - what is single most common cause?

POOR EATING HABITS: And lack of exercise.

Excessive food : Calories in >calories out. Kids are exposed to sugary beverages, sugary cereals and many other processed foods of limited nutritional value. At the same time, portion sizes have grown and children are spending less time outdoors engaged in physical activity. The combination is a killer and children today will have a shorter lifespan than their parents.

Eating junk food: 1. unhealthy food 2. inadequate physical activity 3. frequent snaking on sugary/fatty foods 4. environmental factors such as school lunches, daycare 5. gentics: this is a relatively rare cause of childhood obesity