Philadelphia School Battles Students’ Bad Diets - NYTimes.com
There was a reason for this. While research suggests that as little as an extra 200 calories a day can make an adult overweight, a recent study led by Gary D. Foster, the director of the Center for Obesity Research and Education at Temple University, found that children were getting 360 calories a day from chips, candy and sugary drinks — all for an average of $1.06.
…
Scientists have demonstrated the power of sugar since at least 1974, when a Brooklyn College professor, Anthony Sclafani, found that lab rats were so drawn to Froot Loops that they would suppress their natural fear to eat in the exposed areas of their cages. Researchers using brain imagining technology have since found that foods high in sugar or fat activate the same reward system as cocaine and other drugs, and can also set off the release of the neural chemical dopamine, which can cause the brain to override the biological brakes that prevent overeating. (source)