Читать книгу Intermittent Fasting For Dummies - Janet Bond Brill - Страница 19

For more than a hundred thousand years, humans roamed the earth. They were foragers, so they’d fast until they found, caught, or killed their food. Like so many animals in the wild, human’s paleolithic ancestors regularly experienced extended time periods with little or no food. The timing of eating depended on the availability of food; they ate opportunistically. Because humans evolved in environments where food was relatively scarce, they developed numerous adaptations that enabled them to function at a high level, both physically and cognitively, when in a food-deprived/fasted state. Importantly, metabolic, endocrine, and nervous systems evolved in ways that facilitated high levels of physical and mental performance when in the fasted state (from approximately 12 to 36 hours without food). Both the metabolic shift to ketone utilization (a chemical derivative of fat), and adaptive responses of the brain and nervous system to food deprivation play major roles in the fitness-promoting and disease-allaying effects of intermittent fasting.

Hunter-gatherers gathered berries off bushes; dug up tubers; hunted mammals; scavenged meat, fat, and organs from previously killed carcasses; and discovered how to fish and hunt with spears, nets, bows, and arrows. Furthermore, their activity level is a far cry from the sedentary lifestyle so many people today lead. By the 20th century, most hunter-gatherers had vanished from the face of the earth (currently only a few scattered tribes of hunter-gatherers remain on the planet).

Then came farming

Some 10,000 to 12,000 years ago, things began to change. Homo sapiens altered their lifestyle from hunting and gathering to a more sedentary routine of farming — what’s termed the agricultural revolution. The human diet also took a major turn with the invention of agriculture. The domestication of grains created a plentiful and predictable food supply — food security — which allowed for storing surplus food. Provisions became readily available, hence people no longer had to eat opportunistically, and fasting was no longer necessary. The development of agriculture also brought a great societal transformation. People shifted from a nomadic existence to living in permanent communities, agrarian cultures.

The Industrial Revolution changed it all

Then the Industrial Revolution happened in the United States from the mid-19th century until the early 20th century. This shift in work routines permanently altered the way Americans eat. Refrigeration and transportation allowed for storing, packaging, and transporting of foods. Work shifted from farm to factory, and the human-eating schedule went to the three-meals-per-day routine that is the current eating pattern. Today, most Americans eat three meals and multiple snacks and rarely go more than four daytime hours without eating.