Many wonder the reason why Americans are so much fatter than Europeans, when we both each comparable amounts of food, and after researching the topic I think I may have found an answer!
High fructose corn syrup.
It's in everything you eat, unless you specifically choose foods that don't have it.
What is it?
High fructose corn syrup is a sugar, very similar to sucrose, or table sugar.
Why is it a problem?
Because it is in everything. Read just about any box's ingredients and you're likely to find it as one of the top ingredients. This is essentially like eating spoonfuls of sugar every day, and I am of the belief that this is the cause of overweightness in America.
The reason why I think it is the problem, is because due to the quantity and cheapness to produce, and there is legislation in Europe which limits the addition to food products.
Humans love sugar and sodium, most living creatures do, and so it is a weak addictive as well. We like foods that taste good, and sugar tastes good, so we buy it again.
Back when we weren't so reliant on junk foods and T.V. dinners, and families cooked dinner for everyone, America wasn't known for being overweight. Now it is different, and we aren't cooking our meals from scratch.
Need more? Here's some resources.
http://www.sfgate.com/cgi-bin/article.cgi?f=/chronicle/archive/2004/02/18/FDGS24VKMH1.DTL
http://www.westonaprice.org/motherlinda/cornsyrup.html
http://www.thenutritionreporter.com/fructose_dangers.html
http://www.thehealthierlife.co.uk/article/3059/high-fructose-corn-syrup.html