A composite visualization of (right to left) an overweight male toddler an obese school-age boy and an obese adult male. All are depicted with visible cardiovascular system subcutaneous fat and some skeletal bones. Overweight and obesity rates among children ages 2-19 have more than tripled since 1970. The school-age boy drinks a soda pop one of the main sources of low-nutrient calories consumed by young people in the U.S. Photo credits: Ed Yourdon and Steven Fruitsmaak