A study from Princeton published in the February issue of the journal Pharmacology, Biochemistry and Behavior(PDF) shows that high fructose corn syrup (HFCS), used as a cheap sweetener in everything from Coke to Progresso soup, is not the same as table sugar, namely for the way that it makes you gain 48% more weight.

http://www.foodpolitics.com/wp-content/uploads/HFCS_Rats_10.pdf

Since HFCS was introduced into the American food supply as a cost-effective sweetener, the population's obesity rate has shot up from 15% in 1970 to nearly 33% today.