Yes, there is something in the meat. (I just read
The End of Food, so that's where the following comments are coming from.) Most of what we eat is processed to until much of its natural flavour is lost. To replace this lost yumminess, food manufacturers rely almost entirely on three additives: fat, sugar and salt. Quite a lot of commercial food contains all three, and all three make you fat.
The human body evolved during cycles of food scarcity and as a result of this, holds onto any fat it can get its hooks into as a kind of "snack" for times of famine. We also evolved to eat a very small amount of meat - about a twentieth of what the average American eats today.
Apart from the meat, there's the problem of high-fructose corn syrup. I can't remember the exact details, but the most commonly used sweetener in most of our food is one that does not penetrate the part of our brain that tells us whether or not we are satisfied, or "full". So we tend to consume endless amounts of sweets and sugary drinks because we never get that message. Unfortunately, it's also a type that the body can not metabolize very well, and makes us fat.
I don't know why Americans are getting fatter than Canadians though - we get a lot of the same products, but I don't know anyone who isn't into some kind of physical activity. Even my 90 year old grandma potters around in the garden all day. So maybe that helps. I also don't know a lot of people (besides teenagers) who like to drink pop. (We prefer beer.
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