(This is Part 10 of a continuing series. Go back to Part 9.)
This trend of increased meat and dairy consumption has accelerated since World War II, to the point that most people in Western societies now eat meat and/or dairy at every meal. This is an extraordinary new development in human history, and while it's been advancing for a century or two, has existed in its present form only for the last couple of generations.
As societies have become wealthier, two types of foods that were negligible before have become predominant: animal foods and processed foods. Both of these types of foods tend to have caloric densities that are vastly higher than the unprocessed plant foods that were the mainstay of our diet previously.
Consider: We go to a fast food restaurant and order a cheeseburger (1200 calories/pound). Or we sit in front of the TV and eat potato chips (2500 calories/pound).
Moreover, the meat we eat nowadays is far different from what it used to be. An animal in the wild normally has about 12-15% body fat. But today's livestock, deliberately fattened, can be several times that.
Most animal foods eaten today are 25-75% fat by calories, ranging from chicken (25%) and turkey (35%) to fish (25 to 75%), eggs (70%), cheese (70%), steak (70%) and so on. Compare that to grains (average 10-11%), vegatables (average 6-7%) and fruits (average 4-5%).
And let's remember that fat is 9 calories per gram whereas protein and carbohydrates are 4 calories per gram. So as human diets become higher in animal foods they also tend to become much higher in fat and calories as well.
Then there's processed foods, which are often fat-carb combinations—a calorie-dense mixture of carbohydrates and fats. Examples are potato chips, cakes, pies, cookies, french fries, pizza, lasagna, ice cream, croissants, meat tacos, chocolate bars and on and on.
A second major category of processed foods is refined carbohydrates. As in: white bread, french bread, noodles, bagels, pasta, white rice, sugared breakfast cereals, candy. Or a 20-ounce soda with the equivalent of 17 teaspoons of sugar. Besides being almost devoid of fiber, minerals and vitamins, such foods quickly add excess calories.
Our body's calorie-regulation systems, which developed over millions of years of low-density natural foods, are deceived by these "modern" foods, which tend to be much more calorie-dense.
So we eat a bacon cheeseburger or a piece of chocolate cake and our calorie-regulation systems tend to misjudge the full extent of the calories coming in, and so don't signal "full" as readily as if we're eating natural, low-fat, plant-based foods.
In addition, as mentioned above, we're naturally drawn to calorie-dense foods—but a Big Mac and fries weren't on the menu back when we lived in nature and developed this instinct. Thus we naturally, without thinking about it, ate far fewer calories for most of human history.
(This is the end of Part 10. Go to Part 11.)
—jim sloman, 9.24.04 for Jul 26
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